Readers of of my December 2014 blog: "How Winters Are Changing":
( http://theminnesotarosegardener.blogspot.com/2014/12/how-winters-are-changing.html )
will recall that national climatology statistics clearly show that climate change is more pronounced in the northern latitudes and, in particular, Minnesota. My 53-year Extreme Minimum Temperature (EMT) trend lines (1962-2014 inclusive) statistically predict that the Twin Cities area will consistently be in USDA Zone 6 (where St. Louis, Detroit and Louisville used to be), within the next seven or eight years. In fact, the EMT recorded in early January for the winter of 2015 was -11 F, which is above the trend line and within one degree of Zone 6. In fact, most of our winters since the year 2000 have been in Zone 5, with only three in Zone 4, including last year, which was an anomaly all over the northern states. Yet, the USDA persists in rating the Twin Cities in Zone 4, based on 2005 data, now 10 years out of date. Close enough for government work? Not in my book!
This week, Minnesota Public Radio published a special report on the phenomenon of northern climate change with the article: "Climate Change in Minnesota: 23 Signs". And even though many of my readers don't live in Minnesota, or even in the United States, this makes very interesting reading. I will conclude with a sentence that I have written repeatedly:
"You might argue why it’s warmer in Minnesota these days, but you can’t deny the fact that it is warmer, and that has important implications for Northern Gardeners."
Here's that excellent Minnesota Public Radio article; enjoy and let me know what you think:
http://www.mprnews.org/story/2015/02/02/climate-change-primer
Jack Falker
February 2015
jrfalkersr@gmail.com
Thursday, February 5, 2015
Thursday, January 29, 2015
Composting in Winter
Composting isn't just for warm weather. It can be a year-round activity, which, in the winter months, allows you to compost "green" kitchen scraps and lots of coffee grounds for use on your roses in the spring. Even here in Minnesota, where the ground usually freezes hard and deep in winter, compost piles will generally remain mostly unfrozen beneath the snow because of the heat generated in the decomposition process. If you dig through the snow and open up holes in the pile, you can keep adding to it all winter. But that hasn't been necessary here this winter, as you can see in the picture below. Our low temperature in January was -11 f., which puts us almost in USDA Zone 6. We had a lot of days above freezing in late December and throughout January, and what little snow we had is just about gone.
As usual, some folks in Minnesota go to extremes. I heard a funny story in mid-November, when it was actually much colder and snowier than was in December and January. Someone, here in Minneapolis, had moved their composting operation into their basement for the winter, in one of those fancy (and expensive) rotating drums. I guess I was kind of incredulous and asked what they were going to do with it in the basement. The guy was kind of put out when I asked him why they just didn't leave it outside to compost naturally. I really can't imagine having that decomposition process going on in my basement. I just make a pile outside, where everything happens naturally, and the earthworms have a field day, leaving their castings (down deep where it's warm), year-round.
Today, I dumped about 200 lb. of Starbucks coffee grounds in my pile, along with lots of green kitchen scraps. When I opened up the pile, a cloud of steam puffed out; proof positive that the composting process is alive and well in mid-winter. Here's how it looked, after I finished pulling the shredded oak leaves back on top. Note the lack of snow and the two Christmas trees behind the pile doing double duty as a habitat for birds and other winter critters. The white stake in the foreground is a terminal post for my electric fence, which comes up from underground at that point for use in the summer. The small white stakes to the left, in the little bit of snow that's left, mark spots where I have seeded pollinating plants for stratification over the winter. This area around my mulch pile is one of several insectaries, designed to attract bees and other beneficial insects to my rose gardens. (See http://theminnesotarosegardener.blogspot.com/2014/12/bugs-and-roses.html ).
Tuesday, January 6, 2015
Don't "Sweat" the Wind-Chill on Your Roses!
Tonight is likely to be the coldest night of winter 2015, in the Twin Cities. Temperatures are predicted to fall to -13 F (-25 C) at Minneapolis-St. Paul Airport, which, in the context of winter history in Minnesota, is no big deal (It's 0 F [-18 C] right now at 9 PM). That will put us in the upper reaches of USDA Zone 5 for the year, i.e. approaching Zone 6, when the USDA still has us listed in Zone 4 (incorrect in my opinion).
Author's note: The actual low temperature recorded on the night mentioned above (January 6, 2015) was -11 F, which should be the extreme minimum temperature (EMT) for 2015. This puts the Twin Cities (MSP) just one degree shy of a USDA Zone 6 winter in 2015.
But to listen to the apoplectic, Twin Cities TV weather folks creating "shock and awe" among their listeners, the real news is that wind-chills are going to reach a "dangerous" -30 to -35 F (-34 to -37 C) by tomorrow morning. By doing this every day in the winter, they have created the idea among a very large number of people that temperatures are much colder than they really are. In point of fact, wind-chill is only relevant to the cooling of the exposed flesh of warm-blooded animals (with no fur like us, unless you grow a beard). It has nothing to do with the temperature of cars or houses or, most importantly, plants, which in our case means ROSES! (For a full explanation of the effects of windchill on roses, see the quotes below from my wind-chill blog of last January).
Looking at it another way, if you're foolish enough to run around outside in your birthday-suit tomorrow morning in Minneapolis you're going to freeze your "you-know-what" off in the "relative" -30 to -35 F wind-chill, because of the effect of the cold temperatures on your exposed flesh, plus the wind which doesn't allow your body to warm itself. But if you dress warmly with a coat, hat, gloves, ear-protection and maybe a scarf over your nose, you have nothing to worry about, except the real ambient temperature of -13, which is cold enough, without trying to make it sound worse.
Here a couple of images of one of my Buck Earthsong beds taken last year at this time, when we had a lot more snow than we have now, which was a good thing then:
And here are several quotes from my article "How Windchill Affects Roses" from last year at this time:
First, from a National Weather Service article:
"Wind chill is the term used to describe the rate of heat loss on the human body resulting from the combined effect of low temperature and wind. As winds increase, heat is carried away from the body at a faster rate, driving down both the skin temperature and eventually the internal body temperature. While exposure to low wind chills can be life threatening to both humans and animals alike, the only effect that wind chill has on inanimate objects, such as vehicles, is that it shortens the time that it takes the object to cool to the actual air temperature (it cannot cool the object down below that temperature)."
And from a Kansas State University article:
Plants Don’t Care if the Wind Chill Tanks
"When wind chill temperatures plummet, gardeners chafe about their landscape and fruit plants' odds for survival. Some gardeners worry too much.... Cold can be a killer if people are growing marginally hardy plants or if air temperatures drop well below what's usual where they live. Hard freezes are particularly destructive when plants aren't fully dormant. But cold and wind chill aren't the same thing. Wind chill only affects warm-blooded animals -- including people. It's an indexed, scientific measure of how wind speed and air temperature combine to impact animal heat loss.... We know, for example, that our heat-loss rate will speed up as the air temperature drops. The faster the wind is blowing, however, the more dramatic that heat loss is going to be .... Wind chill has no meaning for plants. Unlike warm-blooded animals, they don't try to maintain a particular body temperature year-round".
And another:
"Of course, we know that roses feel the winter cold and die back according to the level of protection afforded them. And winter-winds do, of course, have an effect on that die-back, desiccating the canes, but the important thing to understand is that wind does not make a plant "feel" colder than the actual temperature, even though it shortens the time it takes for the plant to reach that temperature.
And this one is important:
Here's an example: Suppose that the ambient temperature is 35 F and the wind is blowing 30 MPH. According to an NWS chart, the wind chill is 22 F. So are your roses freezing? Or, better yet, are the puddles in your garden freezing? Of course not, because the freezing point of water is 32 F. However, if you go out in your garden without a hat and jacket, you will feel like it is 22, not 35, because of the combined effects of the cold temperature and the high wind on your flesh."
And here's that whole article from last January:
http://theminnesotarosegardener.blogspot.com/2014/01/how-windchill-affects-roses.html
Let me know if you have any questions. I'll be safely bundled up tomorrow morning when I go outside.
Jack Falker
@mnrosegardener
jack@falkerinvestments.com
01/06/2014
Author's note: The actual low temperature recorded on the night mentioned above (January 6, 2015) was -11 F, which should be the extreme minimum temperature (EMT) for 2015. This puts the Twin Cities (MSP) just one degree shy of a USDA Zone 6 winter in 2015.
But to listen to the apoplectic, Twin Cities TV weather folks creating "shock and awe" among their listeners, the real news is that wind-chills are going to reach a "dangerous" -30 to -35 F (-34 to -37 C) by tomorrow morning. By doing this every day in the winter, they have created the idea among a very large number of people that temperatures are much colder than they really are. In point of fact, wind-chill is only relevant to the cooling of the exposed flesh of warm-blooded animals (with no fur like us, unless you grow a beard). It has nothing to do with the temperature of cars or houses or, most importantly, plants, which in our case means ROSES! (For a full explanation of the effects of windchill on roses, see the quotes below from my wind-chill blog of last January).
Looking at it another way, if you're foolish enough to run around outside in your birthday-suit tomorrow morning in Minneapolis you're going to freeze your "you-know-what" off in the "relative" -30 to -35 F wind-chill, because of the effect of the cold temperatures on your exposed flesh, plus the wind which doesn't allow your body to warm itself. But if you dress warmly with a coat, hat, gloves, ear-protection and maybe a scarf over your nose, you have nothing to worry about, except the real ambient temperature of -13, which is cold enough, without trying to make it sound worse.
Here a couple of images of one of my Buck Earthsong beds taken last year at this time, when we had a lot more snow than we have now, which was a good thing then:
First, from a National Weather Service article:
"Wind chill is the term used to describe the rate of heat loss on the human body resulting from the combined effect of low temperature and wind. As winds increase, heat is carried away from the body at a faster rate, driving down both the skin temperature and eventually the internal body temperature. While exposure to low wind chills can be life threatening to both humans and animals alike, the only effect that wind chill has on inanimate objects, such as vehicles, is that it shortens the time that it takes the object to cool to the actual air temperature (it cannot cool the object down below that temperature)."
And from a Kansas State University article:
Plants Don’t Care if the Wind Chill Tanks
"When wind chill temperatures plummet, gardeners chafe about their landscape and fruit plants' odds for survival. Some gardeners worry too much.... Cold can be a killer if people are growing marginally hardy plants or if air temperatures drop well below what's usual where they live. Hard freezes are particularly destructive when plants aren't fully dormant. But cold and wind chill aren't the same thing. Wind chill only affects warm-blooded animals -- including people. It's an indexed, scientific measure of how wind speed and air temperature combine to impact animal heat loss.... We know, for example, that our heat-loss rate will speed up as the air temperature drops. The faster the wind is blowing, however, the more dramatic that heat loss is going to be .... Wind chill has no meaning for plants. Unlike warm-blooded animals, they don't try to maintain a particular body temperature year-round".
And another:
"Of course, we know that roses feel the winter cold and die back according to the level of protection afforded them. And winter-winds do, of course, have an effect on that die-back, desiccating the canes, but the important thing to understand is that wind does not make a plant "feel" colder than the actual temperature, even though it shortens the time it takes for the plant to reach that temperature.
And this one is important:
Here's an example: Suppose that the ambient temperature is 35 F and the wind is blowing 30 MPH. According to an NWS chart, the wind chill is 22 F. So are your roses freezing? Or, better yet, are the puddles in your garden freezing? Of course not, because the freezing point of water is 32 F. However, if you go out in your garden without a hat and jacket, you will feel like it is 22, not 35, because of the combined effects of the cold temperature and the high wind on your flesh."
http://theminnesotarosegardener.blogspot.com/2014/01/how-windchill-affects-roses.html
Let me know if you have any questions. I'll be safely bundled up tomorrow morning when I go outside.
Jack Falker
@mnrosegardener
jack@falkerinvestments.com
01/06/2014
Sunday, December 21, 2014
How Winters Are Changing
Climate Central (CC), an independent organization that surveys and conducts research on climate change, recently published a series of maps showing the relative extent of climate change in all regions of the United States. What's most notable about these maps is that the northern tier of states has experienced the most winter-warming since 1970, and that the upper-midwest, especially Minnesota, has warmed more than the any other area. Here's that article:
http://www.climatecentral.org/news/winter-climate-trends-18409
What really jumped out at me when I saw CC's maps was that they show exactly (and not surprisingly) what my own trend-line graphs of Extreme Minimum Temperatures (EMT) indicate, which is (1) that the whole northern tier of states has gotten significantly warmer and (2) that the further north you go the sharper the change. The difference between CC's work and mine is that the Minnesota Rose Gardener graphs cover a longer period, i.e. since 1962 vs.1970, and that my graphs are dynamic, in that the trend lines, being statistically valid, are predictive of the future.
Here is CC's map of the United States:
Note that the upper-midwest generally has warmed more than the rest of the country and that the areas around and just north of the Twin Cities, and in the northwest corner of Minnesota, have warmed more than just about anywhere else in the country (my upstate NY and New Hampshire readers will be happy to note they are paralleling the upper-midwest).
This is very clear when you look at my 53 year EMT trend-line graph for the Twin Cities. Note the relatively sharp slope of the line and how it points upwards to USDA Zone 6. I will show several other cities' EMT graphs below, which show definite warming, but with shallower trend lines than Minnesota, just as the CC map shows.
Here is a regional close-up of the upper-midwest from CC's article:
And now let's look at the EMT chart for Milwaukee to see the difference in the slope of their warming trend-line:
Note that the slope of the trend-line, while definitely upward, is not quite as sharp as the Twin Cities' line and, while they've had two winters solidly in USDA Zone 7 in this decade, the line predicts that it will be quite a few years before they move into Zone 7.
Here is Detroit, which has now crossed into Zone 7, as predicted by the trend line, albeit with a very shallow slope over quite a few years.
Here is CC's regional close-up of the Ohio Valley:
And here is my EMT graph of St. Louis, which has moved solidly into Zone 7, with a fairly sharp upward trend:
And here is Chicago, which perennially was in Zone 5 but now has moved solidly into Zone 6. Note that the slope of its trend line is very similar to Milwaukee's, which should be no surprise, but they too are quite a long way from being consistently in Zone 7.
Finally, here is Indianapolis, which has a trend line a bit shallower than Chicago or Milwaukee, but the line projects that it is almost in Zone 7 (and actually had a Zone 8 winter in 2012).
So What Happened Last Winter?
That's a perfectly logical question, in the face of all the trend line evidence of warming. Most climate scientists believe that the "polar vortex" phenomenon we experienced last year was (or is) a product of climate change and that it is unlikely to repeat itself with regularity. However, that is certainly not to say that it won't happen again or that we might not see variations of it. Note in the graphs above that last winter was a big departure from all trend lines, especially in some of the warmer midwest cities like Detroit, St. Louis and Indianapolis. With a developing El Nino, which is also a child of climate change, it seems unlikely that we could see another major vortex incursion in the winter of 2014-15. For a more detailed explanation of the polar vortex and its presumed causes, please see my October 2014 blog: "Winter Protecting Roses in a Climate Change Environment".
http://jack-rosarian.blogspot.com/2014/10/winter-protecting-roses-in-climate.html .
Conclusion
Finally, I would like to emphasize the statistical validity of the trend-lines generated on the graphs in this article. As mentioned earlier, these trends are both predictive and dynamic, in that you should be able to extend them into the future with a fair degree of accuracy, regardless of one year anomalies in either direction. For example, it is logical to conclude that the Twin Cities will see more winters in Zone 6 than in Zone 4 in coming years and that, within the next seven or eight years we will see consistent Zone 6 winters. This can be clearly seen on the St. Louis graph, as it progressed along its trend line to where it crossed into Zone 7. And the same can be seen on the Detroit chart, although its change was more gradual and over more years.
Having said all of this, I am not implying that winter-protecting roses isn't important to prevent the inevitable freeze-thaw cycle. Rather, I am saying that extreme measures, such as the Minnesota Tip, are unnecessary, if sensitive roses are properly planted with bud unions below ground. Please see the article cited above, as well as my September 2013 article "Winter Protecting Your Roses" for more complete explanations:
http://jack-rosarian.blogspot.com/2013/09/winter-protecting-your-roses.html .
Jack Falker
@mnrosegardener
jack@falkerinvestments.com
December 2014
http://www.climatecentral.org/news/winter-climate-trends-18409
What really jumped out at me when I saw CC's maps was that they show exactly (and not surprisingly) what my own trend-line graphs of Extreme Minimum Temperatures (EMT) indicate, which is (1) that the whole northern tier of states has gotten significantly warmer and (2) that the further north you go the sharper the change. The difference between CC's work and mine is that the Minnesota Rose Gardener graphs cover a longer period, i.e. since 1962 vs.1970, and that my graphs are dynamic, in that the trend lines, being statistically valid, are predictive of the future.
Here is CC's map of the United States:
Note that the upper-midwest generally has warmed more than the rest of the country and that the areas around and just north of the Twin Cities, and in the northwest corner of Minnesota, have warmed more than just about anywhere else in the country (my upstate NY and New Hampshire readers will be happy to note they are paralleling the upper-midwest).
This is very clear when you look at my 53 year EMT trend-line graph for the Twin Cities. Note the relatively sharp slope of the line and how it points upwards to USDA Zone 6. I will show several other cities' EMT graphs below, which show definite warming, but with shallower trend lines than Minnesota, just as the CC map shows.
Here is a regional close-up of the upper-midwest from CC's article:
And now let's look at the EMT chart for Milwaukee to see the difference in the slope of their warming trend-line:
Note that the slope of the trend-line, while definitely upward, is not quite as sharp as the Twin Cities' line and, while they've had two winters solidly in USDA Zone 7 in this decade, the line predicts that it will be quite a few years before they move into Zone 7.
Here is Detroit, which has now crossed into Zone 7, as predicted by the trend line, albeit with a very shallow slope over quite a few years.
Here is CC's regional close-up of the Ohio Valley:
And here is my EMT graph of St. Louis, which has moved solidly into Zone 7, with a fairly sharp upward trend:
And here is Chicago, which perennially was in Zone 5 but now has moved solidly into Zone 6. Note that the slope of its trend line is very similar to Milwaukee's, which should be no surprise, but they too are quite a long way from being consistently in Zone 7.
Finally, here is Indianapolis, which has a trend line a bit shallower than Chicago or Milwaukee, but the line projects that it is almost in Zone 7 (and actually had a Zone 8 winter in 2012).
So What Happened Last Winter?
That's a perfectly logical question, in the face of all the trend line evidence of warming. Most climate scientists believe that the "polar vortex" phenomenon we experienced last year was (or is) a product of climate change and that it is unlikely to repeat itself with regularity. However, that is certainly not to say that it won't happen again or that we might not see variations of it. Note in the graphs above that last winter was a big departure from all trend lines, especially in some of the warmer midwest cities like Detroit, St. Louis and Indianapolis. With a developing El Nino, which is also a child of climate change, it seems unlikely that we could see another major vortex incursion in the winter of 2014-15. For a more detailed explanation of the polar vortex and its presumed causes, please see my October 2014 blog: "Winter Protecting Roses in a Climate Change Environment".
http://jack-rosarian.blogspot.com/2014/10/winter-protecting-roses-in-climate.html .
Conclusion
Finally, I would like to emphasize the statistical validity of the trend-lines generated on the graphs in this article. As mentioned earlier, these trends are both predictive and dynamic, in that you should be able to extend them into the future with a fair degree of accuracy, regardless of one year anomalies in either direction. For example, it is logical to conclude that the Twin Cities will see more winters in Zone 6 than in Zone 4 in coming years and that, within the next seven or eight years we will see consistent Zone 6 winters. This can be clearly seen on the St. Louis graph, as it progressed along its trend line to where it crossed into Zone 7. And the same can be seen on the Detroit chart, although its change was more gradual and over more years.
Having said all of this, I am not implying that winter-protecting roses isn't important to prevent the inevitable freeze-thaw cycle. Rather, I am saying that extreme measures, such as the Minnesota Tip, are unnecessary, if sensitive roses are properly planted with bud unions below ground. Please see the article cited above, as well as my September 2013 article "Winter Protecting Your Roses" for more complete explanations:
http://jack-rosarian.blogspot.com/2013/09/winter-protecting-your-roses.html .
Jack Falker
@mnrosegardener
jack@falkerinvestments.com
December 2014
Monday, December 8, 2014
"Bugs and Roses"
This is part two of my July 2014 article "Controlling Spider Mites and Thrips on Roses Without Insecticides-- Part One". In case you haven't seen it, here's that article:
http://theminnesotarosegardener.blogspot.com/2014/07/controlling-spider-mites-and-thrips-on.html
The underlying purpose of these two articles is to demonstrate that attracting, introducing and nurturing beneficial and predatory insects to control common pests like spider mites and thrips is both possible and desirable in a rose garden. I finally realized, after many years of spraying everything from organophosphates like Orthene, neonicotinoids like imidicloprid (Merit) and pyrethroids like Demand CS (which is what I thought I was supposed to do to control everything from aphids to Japanese beetles), that what I was really doing was wiping out naturally occurring beneficial and predator insects. For example, I suddenly realized that I no longer was seeing lady beetles and lacewings, which are natural predators for spider mites. It's no wonder because, instead of tediously picking Japanese beetles off my plants and drowning them in soapy water, I sprayed them with Demand CS, which works really well, but also wipes out all other beetles (like lady bugs) and just about every other predatory insect in the garden. As a result, I ended up with a massive infestation of aphids (something I hadn't seen in many years) because I had destroyed all their predators, in my efforts to deter Japanese beetles.
Then, early in 2014, my compatriot-rosarian Paul Zimmerman mentioned a new book by Jessica Walliser, "Attracting Beneficial Bugs to your Garden", which changed my way of thinking about controlling insect pests in my gardens. Here's a link to that book, which is available both new and used on Amazon:
http://www.amazon.com/Attracting-Beneficial-Bugs-Your-Garden/dp/1604693886/ref=sr_1_1?ie=UTF8&qid=1417916500&sr=8-1&keywords=attracting+beneficial+bugs+to+your+garden
Well, after reading Jessica's book multiple times, I decided I had to try what she advocates, and I learned a lot. First, the good news: I was very successful in controlling thrips without insecticides all last summer and, as a direct result, beneficial insects, including honey bees, bumble bees, mason bees, syrphid flies, lacewings and predatory wasps have flourished, on their own. Second, the relatively bad news: spider mites were harder to control than I thought, when I wrote my July article, above.
I washed my roses at least every other day and I just couldn't get rid of the spider mites altogether. Just when I thought I had the upper hand (as I did in July when I wrote the article) they would come back, not to the extent where I would see a lot of webbing, but just to where they would appear on new growth. If you were to look with a magnifying glass at the wilted leaf just under the bud in the picture below, you would find just a thread or two of mite webbing. So the wilted leaf is a tell-tale sign; something it has taken me a long time to understand. Those leaves die and become "crispy", as the mites multiply and move on to other new growth. I was able to control the mites by cutting off that leaf stem and washing the plant, but they continued to pop up elsewhere on other new growth, no matter how much I washed.
I really didn't want to use a miticide because I had imported large quantities of predatory mites (at least 100,000 cucumeris and fallacis mites) from California and I wanted them to do their job on both the mites and thrips, before applying a miticide, which would likely take down most of the mites, including predators. I made it until late August without using anything but water, but finally I had to do something because even my most resistant roses were succumbing to blackspot from the constant washing. In August, I made one application of Floramite and that took care of the spider mites. I won't know until spring if I killed all the predators (Fallacis mites are supposed to be hardy enough to overwinter in Minnesota) so we'll have to wait and see. I'm not giving up on this, however. Next spring I will start washing earlier and, if I can't control the mites with existing predators, such as lady beetles, which I didn't have in 2014, I will reintroduce more predatory mites. I still believe it will work if I get enough predators on the plants
Thrips (both singular and plural, i.e., one insect is called a thrips)
Given the persistence of spider mites, I was pleasantly surprised to find that I was able to control thrips with the beneficials I was able to introduce and/or attract to my garden this summer. Here's what a Carefree Beauty bud with thrips running around in it looked before my beneficials got to work. By the way, any bud that looks like this gets plucked and disposed of someplace where the thrips can't fly back into the garden. That's the first line of defense when you're not spraying insecticides.
As long as you don't spray things that kill them, natural thrips predators, such as minute pirate bugs and syrphid flies are fairly easy to attract to the garden with plantings, such as oregano, yarrow, alyssum and cosmos. And predatory mites can be imported from an insectary, such as Rincon-Vitova in California. In talking to Jan Dietrick, who runs Rincon-Vitova, I also learned that beneficial nematodes released in the soil of each rose bed will feast on the pupa of thrips, eliminating something like 80% of them before they become active on the plants. I ordered millions of the nematodes Jan recommended, as well as thousands of cucumeris predatory mites and 500 minute pirate bugs, in addition to 500 lady bugs for spider mite control. By the way, these beneficials aren't terribly expensive, compared with what I've been spending on insecticides. However, the required overnight shipping is quite expensive so it's advisable to combine as much as you can in one shipment. Here's Rincon-Vitova's website: http://www.rinconvitova.com/
I'm not sure exactly what did the trick on the thrips but, after they got off to a head start on me (see the picture above), I was able to control them from mid-summer onward. I'm pretty confident that the nematodes were effective and I could see the syrphid flies, which arrived in droves, probing around in the flowers, so I believe the combination of those two worked. The minute pirate bugs arrived too late to become well established, but I'm sure they will be around next summer, and I'm not sure about the predatory mites because they were too hard to see but I saw enough of them with my magnifying glass to know they were there.
Here's an interesting statement from an article on thrips by Applied Bio-Nomics, the producer of the predatory mites I purchased from Rincon-Vitova: "The first thing to know is that I do not believe that a single thrip has died from an insecticide registered against thrips for the past three
years .... I will bet you that they died from the soap effect of the spreaders and the stickers rather than the active ingredients. So,don’t even think about using chemicals against thrips.... Another even more important reason not to use chemicals is because there is now considerable research that shows that sub-lethal chemical attacks actually induce the thrips to lay more eggs. "
You can find this article and several other equally interesting articles on Applied Bio-Nomics' website: http://www.appliedbio-nomics.com/
So, according to this expert, a chemical like Conserve SC (spinosad), the insecticide of choice for thrips, doesn't kill thrips, it just kills the beneficials like syrphid flies and minute pirate bugs that attack thrips. This is completely opposite to what we have been taught to believe as gardeners.
Insectary Effects
Here's how a little insectary corner of one of my rose gardens looked last summer, with oregano, bachelor buttons, cosmos, dill, yarrow and a few other things to attract beneficials (Buck's Prairie Harvest is to the right). When I took this picture, this little garden was teeming with wasps, bees and other beneficial insects that were nowhere to be found in my garden last year. The idea of doing this, as well as directions on what to plant to attract various beneficials, came directly from Jessica Walliser's book, mentioned earlier. I plan to expand my insectary efforts next year, which will include removing several more roses to make room for more beneficial bug-attracting plants. In short, this really works!
Here's a picture of a bumble bee on one of my Earth Song plants last summer. I was really amazed at how many bees showed up in my gardens after I stopped spraying.
Here's another bumble bee on one of the many sunflowers I planted last summer to attract beneficials. I have no idea where all the varieties of bees (including many honey bees) came from but I did notice, with great interest, that the bumble bees were going in and out of a nest they had made alongside a drain pipe, just a few feet from where I had planted a stand of sunflowers to attract them. No coincidence there!
One of the most important things Jessica Walliser talks about early in "Attracting Beneficial Bugs to Your Garden" is the need to be patient. When there is a large infestation of insects like aphids or spider mites, it takes time to build up enough predator mites and insects to feed on them. I believe that's what my experience was with the spider mites this summer because I had killed off so many beneficial predators over the years, especially in my efforts to control an infestation of Japanese Beetles, which was especially bad in 2012. I have written several articles about that effort, but I now recognize that the use of the pyrethroid, Demand CS, which is very effective in deterring the beetles, comes at the price of eliminating many beneficial insects (about which a knowledgeable rosarian from the TCRC, Sue Youngdahl, gently reminded me at the time). I'm not going to use it again in my garden, as well as other insecticides, with the possible exception of an occasional miticide, as I did this summer but would really like to have done without. However, it is understandable that large public gardens and commercial growers do not have that luxury in their need to control Japanese beetles on a large scale, where picking them one at a time off the plants would be impossible (and those bugs are really awful and terribly destructive). For example, I noted that the University of Minnesota Arboretum was using a pyrethroid in their rose gardens last summer, which is completely understandable.
What I achieved in one growing season was remarkable and these results have made me want to try even harder next year. Nature is exceptionally responsive to our efforts to protect it, and my own most important lesson is that patience is everything, as we change our practices. The rewards are well worth the inconvenience and extra effort. I'll have more to say about this as we go along, so stay tuned and feel free to ask questions. We can learn together!
Jack
@mnrosegardener (Twitter)
December 2014
Saturday, October 4, 2014
Winter Protecting Roses in a Climate-Change Environment
Here is a PowerPoint presentation I made to the American Rose Society, North Central Division convention in the Wisconsin Dells on September 13th of this year. Some of the presentation is a reprise of my March 2014 Blog: "What the Heck was Wrong with This Winter" https://theminnesotarosegardener.blogspot.com/2014/03/what-heck-is-wrong-with-this-winter_5.html and my September 2013 blog: "Winter Protecting Your Roses" https://theminnesotarosegardener.blogspot.com/2013/09/winter-protecting-your-roses.html
For the most part, the slides speak for themselves. However, where explanation and comments are needed, I will fill in with some of the remarks I made during the presentation.
So here we go....
This is a picture I took of my nicely winter-protected Earth Song bed on Christmas Day 2013, right after we had received 8 inches of new snow cover, thereby providing the best natural winter protection of all. Here in Minnesota, we seldom have to dream of a white Christmas!
But our winters are definitely getting warmer, as we shall see.
Below is my recently updated Minnesota climatology chart showing the Extreme Minimum Temperatures (EMT) for the last 53 years at MSP airport. This is the statistic the USDA uses to determine the cold zones. As you can see, the Twin Cities are no longer consistently in USDA Zone 4b. As a matter of fact, there have only been three nights in Zone 4 in the Twin Cities, since 1999! That hardly puts us in Zone 4 and, as you can see, the mathematically determined trend-line has an upward slope of about 25 radian degrees. If you project that trend-line off the right side of the chart, it would appear that the Twin Cities will begin to see more winters in zone 6 than in zone 4, within the next five years.
The most recent USDA charts were released in 2012, based on 1976-2005 data. In other words, their data, prepared for them by Oregon State University, was already seven years old when they released it and is currently nine years old. Those seven winters were some of the warmest ever recorded, which made the USDA data invalid when they released it.
Good enough for government work? Not in my opinion. We just have to think for ourselves, given the data shown below.
Note that for all of the cities shown below the winter of 2013-2014 was unusually cold, pushing them down into zones that they had not seen in several years. Cities like Chicago, Detroit, Indianapolis and St. Louis were especially hard hit, relative to the much warmer EMTs to which they had become accustomed in recent years. Look at Indianapolis, for example: the winter of 2012 had been zone 8 and 2013 had been zone 7, when the bottom fell out in 2014, dropping them to zone 5.
This is a much bigger swing than the Twin Cities experienced and, even though we experienced a near record number of nights below zero in 2014, most of them were in zones 6 and 5; not a huge variance.
Milwaukee is rated at zone 5b, but they have had only five EMTs in zone 5 since 1999. The rest of the years have been in zone 6 and zone 7; go figure.
Chicago, which was classified in zone 5 for many years, is now classified in zone 6, which is correct, but looking at the Milwaukee and Chicago maps together, it's hard to understand why Milwaukee, just a few miles north is not classified similarly, given the data of the last several years. Looking at the slopes of their respective trend lines (Milwaukee's is steeper), both cities will likely see many winters in zone 7 over the next several years.
Look at Indianapolis: going from zone 8 in 2012, to zone 7 in 2013, to zone 5 in 2014; a big surprise for gardeners there, who aren't accustomed to extensive winter protection.
Detroit, which has perennially been in zone 6 ( I grew up and lived there until age 37, and can't remember anything colder than -10) has had eight winters in zone 7 and one in zone 8 since 1999. They've had only five winters in zone 5 in the last 53 years, and last winter was one of them. This is a much bigger variance than seen in most other Midwest cities. The only thing we ever did to our roses, when I was growing up, was to rake some leaves on the beds. That sure didn't work last winter, when both Lakes Michigan and Huron froze all the way across.
Like Indianapolis, St. Louis' winters dropped two zones from 2012 to 2014; almost making it three zones to zone 5! Suffice to say that no one there was ready for that to happen last winter.
What happened was an incursion of the "polar vortex" a phenomenon that had never been seen in the U.S. to the extent that it was in 2014. Note, in the two graphics below, that unusually warm air, both to the west and east of North America formed a "pincers" around the normal polar vortex, a cyclone of super-cold air rotating tens of thousands of feet above the north pole (south pole too) tipping it over into central Canada and the Midwest USA. Note, in the second graphic below, that it also happened in China and eastern Siberia, which you would expect, but something that was not reported here.
Note that it was as warm in England and Western Europe (just to the right of Greenland on the great circle map below), on February 27th, as it was along the Gulf Coast of the United States; pretty amazing.
Be sure to also read my blog: "Winter Protecting Your Roses", written in September 2013:
Saturday, September 20, 2014
A Potassium Feast for your Roses
For those of us in the cold zones, i.e. USDA zones 3-6 (and maybe zone 7, given last year's polar vortex incursion), now is the time to begin feeding your roses a six week diet of potassium. Here is a quote from my posting on this subject last year at this time:
"In the six weeks before the first hard freeze (i.e., down to about 25 F. at night), give your roses a weekly "potassium feast" in each of those six weeks. Potassium blocks the growth-promoting effects of nitrogen and phosphorous, thereby hardening the canes in time for winter. I've been doing this for more than 20 years and I honestly can't remember the last time I lost a rose to winter weather here in Minnesota. Of course, I do other things to protect my roses from the Minnesota winter, as well. Here is my 2013 article on winter protecting your roses:
http://theminnesotarosegardener.blogspot.com/2013/09/winter-protecting-your-roses.html .
"In the six weeks before the first hard freeze (i.e., down to about 25 F. at night), give your roses a weekly "potassium feast" in each of those six weeks. Potassium blocks the growth-promoting effects of nitrogen and phosphorous, thereby hardening the canes in time for winter. I've been doing this for more than 20 years and I honestly can't remember the last time I lost a rose to winter weather here in Minnesota. Of course, I do other things to protect my roses from the Minnesota winter, as well. Here is my 2013 article on winter protecting your roses:
http://theminnesotarosegardener.blogspot.com/2013/09/winter-protecting-your-roses.html .
I learned this little trick in one of my first rose books: Burpee’s American Gardening Series, "Roses", by Suzanne Frutig Bales. Here's a quote from Suzanne's chapter on winter protection:
“Potassium is an important mineral for sturdy stems and foliage. Weekly feeds of a gallon of liquid potassium (1 tablespoon of muriate of potash (0-0-62), dissolved in 3 gallons of water) per bush, or a granulated feeding of potash magnesium (0-0-22), during the six weeks before the bushes go dormant, will give the bushes an additional boost for winter, extending their hardiness into another hardiness zone, perhaps two. Excess potassium, when available in greater amounts than nitrogen and phosphorus, is known as the ‘potassium feast’. It will block the growth-promoting effects of nitrogen and phosphorus, hardening the canes in time for winter.”
I did a little independent research on this, a couple of years ago, by talking to Dr. Peter Bierman, retired University of Minnesota Professor of Soil, Water and Climate. Peter told me that "... winter hardiness is one of the most important functions of potassium" and that the amounts recommended above..."would be a reasonable amount to apply for winter hardiness insurance and wouldn't be an excessive amount in terms of adding high salts." That squares with my 20 years-plus experience in administering the potassium feast to my roses each fall.
I did a little independent research on this, a couple of years ago, by talking to Dr. Peter Bierman, retired University of Minnesota Professor of Soil, Water and Climate. Peter told me that "... winter hardiness is one of the most important functions of potassium" and that the amounts recommended above..."would be a reasonable amount to apply for winter hardiness insurance and wouldn't be an excessive amount in terms of adding high salts." That squares with my 20 years-plus experience in administering the potassium feast to my roses each fall.
To clarify: The proportions are: 1 TBP muriate of potash per 3 gallons of water (or 1 TSP per gallon). So mixing in a 30 gallon trash container, you would use 10 TBP. Apply one gallon of this mixture on each rose every week. That’s not very much, but remember you’re repeating it six times. I also don't think the exact amount is critical and I usually err a bit on the side of a little more rather than less.
Several folks have asked me if they could "cheat" and do only three or four applications, using proportionally higher doses of potassium. My answer is always: "I don't know, but it's probably better than not doing it at all." However, my observations are that the roses harden off slowly, as the potassium applications continue over the six weeks and the weather gets colder. By the end of six weeks, the canes have turned a lovely shade of red and look ready for the winter ahead. With the canes thus hardened-off, they are less susceptible to the freeze-drying winter winds and naturally suffer less die back than if they their tissues were still soft. I don't know if the roses will harden off as well with fewer, larger applications of potassium, but I suspect not. However, don't let that discourage you if you get started late. A couple of applications will be better than nothing. Just try to get started earlier next year!
Another question is: where one can get potassium immediately to get started? The answer to that is farm stores that sell fertilizers to farmers, who use potassium (potash) as an agricultural fertilizer. Another source is suppliers to commercial growers and greenhouses. In the Twin Cities, the primary sources for me have been Waconia UFC Farm Supply and BFG Supply in St. Paul (formerly J.R. Johnson Supply). It's sold in 50 pound bags for about $.40/lb.
It was pointed out to me by a reader in England that a very good alternative to muriate of potash would be potassium sulfate (0-0-50), which is 50% potassium and 18% sulfate. This is interesting because adding sulfur to your roses in the fall has the effect of lowering the pH of your soil, which is desirable for most of us. A slightly acid pH around 6.0 (plus or minus) is best for roses. (See my posting "Mind your pH":
http://theminnesotarosegardener.blogspot.com/2013/06/mind-your-ph.html.)
Since potassium sulfate has a bit less potassium, i.e. 50%, compared with muriate of postash at 60%, you would use a little more potassium sulfate, perhaps 1.25 or 1.5 tsp per gallon. Again, I don't think the amount is super critical, so I would use 1.5 tsp/gallon to simplify things.
In any event, whatever form of potassium you use, I think this first step in the winterizing process is very important and I'm always amazed that many rosarians aren't aware of it. Mid to late September is the right time for most of us to get started, so find some potassium and begin your roses' feast very soon (I made my first application this week). I think you will be as pleasantly surprised by the results as I have been over the years.
Here are two other articles on the potassium feast that I have previously published:
http://theminnesotarosegardener.blogspot.com/2012/08/potassium-special-k-ration-feast-for.html
http://theminnesotarosegardener.blogspot.com/2013/10/rose-potassium-feast-application-6.html
Jack Falker
@mnrosegardener
jfalkersr@gmail.com
Several folks have asked me if they could "cheat" and do only three or four applications, using proportionally higher doses of potassium. My answer is always: "I don't know, but it's probably better than not doing it at all." However, my observations are that the roses harden off slowly, as the potassium applications continue over the six weeks and the weather gets colder. By the end of six weeks, the canes have turned a lovely shade of red and look ready for the winter ahead. With the canes thus hardened-off, they are less susceptible to the freeze-drying winter winds and naturally suffer less die back than if they their tissues were still soft. I don't know if the roses will harden off as well with fewer, larger applications of potassium, but I suspect not. However, don't let that discourage you if you get started late. A couple of applications will be better than nothing. Just try to get started earlier next year!
Another question is: where one can get potassium immediately to get started? The answer to that is farm stores that sell fertilizers to farmers, who use potassium (potash) as an agricultural fertilizer. Another source is suppliers to commercial growers and greenhouses. In the Twin Cities, the primary sources for me have been Waconia UFC Farm Supply and BFG Supply in St. Paul (formerly J.R. Johnson Supply). It's sold in 50 pound bags for about $.40/lb.
It was pointed out to me by a reader in England that a very good alternative to muriate of potash would be potassium sulfate (0-0-50), which is 50% potassium and 18% sulfate. This is interesting because adding sulfur to your roses in the fall has the effect of lowering the pH of your soil, which is desirable for most of us. A slightly acid pH around 6.0 (plus or minus) is best for roses. (See my posting "Mind your pH":
http://theminnesotarosegardener.blogspot.com/2013/06/mind-your-ph.html.)
Since potassium sulfate has a bit less potassium, i.e. 50%, compared with muriate of postash at 60%, you would use a little more potassium sulfate, perhaps 1.25 or 1.5 tsp per gallon. Again, I don't think the amount is super critical, so I would use 1.5 tsp/gallon to simplify things.
In any event, whatever form of potassium you use, I think this first step in the winterizing process is very important and I'm always amazed that many rosarians aren't aware of it. Mid to late September is the right time for most of us to get started, so find some potassium and begin your roses' feast very soon (I made my first application this week). I think you will be as pleasantly surprised by the results as I have been over the years.
Here are two other articles on the potassium feast that I have previously published:
http://theminnesotarosegardener.blogspot.com/2012/08/potassium-special-k-ration-feast-for.html
http://theminnesotarosegardener.blogspot.com/2013/10/rose-potassium-feast-application-6.html
Jack Falker
@mnrosegardener
jfalkersr@gmail.com
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