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 ).

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