Tuesday, March 26, 2013

Lingering winter

I took this photo of plum trees and spicebush shrubs in our backyard following what the St. Louis National Weather Service has dubbed the Palm Sunday Winter Storm. The official snowfall total at Lambert Field, around 10 miles from our house, was 12.7 inches of snow. I measured 12.0 inches in my backyard, but some melting may have already occurred before I made the measurement. As is typical of late season snowstorms, the snow was quite wet and heavy. Until the breeze picked up later in the morning and the air warmed slightly above freezing, the snow clung to shrubs and trees. The weight of the snow brought down a branch of the blue spruce in the side yard. That branch fell on the nearby blueberry shrub, breaking one of its branches off. Another shrub, a spiraea, suffered stem breakage from the weight of the snow on it. As more of the snow melts, I will check to see if any other woody plants were damaged.

Today I pricked-out seedlings of bok choy, cabbage, broccoli, cosmos, and zinnia from the flat in which each was started into individual cell packs. It was a good activity for a cold, snowy, but sunny afternoon. It felt like winter outside, but on the porch the temperature climbed to 80F.
A year ago, spring came very early and I did not respond in time, losing some unknown portion of the yield I could have gotten from my spring garden. This year I am late getting the ground prepared, not only because we were out of town for several days a few weeks back but also because of the lingering winter weather. Until the snow melts, I won't be able to begin preparation for the peas and onions that should have already been planted, much less the next set of seeds that I should have been preparing for now. Once the snow melts I'll have to check the soil temperature to find out if it is high enough to support seed germination now that we have had a week of very much below average temperatures. A week ago I measured the soil temperature at around 48-50F, which would have been warm enough for many of the spring crops I wanted to plant. I hope it hasn't dropped much. All of this is a good reminder that despite whatever I'd like to think, I'm not in control and nature has no obligation to grant me or anyone else the sort of world we think we should have. The best I can do is try to respond in a timely and appropriate way to whatever is actually happening - and in this case it is winter lingering on.

Thursday, March 21, 2013

Soil re-mineralization for the rest of us

Now that spring is supposed to be here, I should be outside working on garden beds for the earliest spring crops. But we are having a late spring this year, at least compared to recent years. The temperature at the official St. Louis NWS site is 33F as I write. One year ago, it was 81F. The average high for today is 58F.

To really appreciate the difference between last year and this year, compare the picture of two redbuds in my backyard above (the small trees in the foreground), taken yesterday, with the picture below of the same two redbuds taken one year ago.

Last year the redbuds were in full bloom. This year, they haven’t changed much from midwinter. Granted, this year is closer to climatic normal than last ... but even the magnolias and most of the daffodils aren’t blooming yet.

With winter hanging on for at least a few more days, I have had time to read most of the way through Steve Solomon’s new book, The Intelligent Gardener: Growing Nutrient-Dense Food. Unlike his previous book, which I discussed here, this book looks in depth at one topic: why and how to re-mineralize garden soils. I’m really glad Solomon wrote the book because a couple of years ago, I had a subscription to Acres U.S.A. and read about soil re-mineralization and how important it is in that publication. However, Acres U.S.A. is written for farmers rather than gardeners. The articles discussing re-mineralization referred to many books written by and for farmers and their advisers. I could tell that different people used different systems, but I wasn’t up to reading the various books in order to piece together what might make sense for me to use on a garden scale. Fortunately for all of us, Solomon became interested enough in the topic and, as he puts it, honestly passed high school chemistry, so he could read much of the re-mineralization literature and interpret it for gardeners.

The first few chapters of the book explain why soils need re-mineralization and why composting and manuring are not sufficient to restore a full mineral balance to most soils, although they do benefit soils by feeding the soil microfauna. For those of us, myself included, who grow by the organic method as explicated by Organic Gardening magazine, we have much to learn. Solomon isn’t knocking organic gardening methods; rather, he wants to extend them to take into account what has been learned by soil chemists and successful holistic farmers about the need for and practice of re-mineralizing farm soils. Soils need re-mineralization because they are leached by rainfall and because typical agricultural, horticultural, and landscaping practices (even organic practices) remove some of the soil’s mineral reserves without replacing them and may create excesses in some minerals that are harmful to crops. Crops grown on such soils will not be as nutritious as they could and should be to sustain their own health against disease and insect attack. Since they lack nutrition, they cannot create the proper level of health in those of us who eat them.

The good news is that we can gradually replace the missing minerals in our soils and reduce excessive levels where those occur; Solomon’s book tells us how to do both. For those of us who don’t have the inclination to have our soil tested, Solomon offers an updated version of his complete organic fertilizer recipe. It’s not quite as simple to prepare as his earlier recipe because his research has led him to tweak the mixture depending on where you live, but it should also work a little better than the version in his earlier book. For those of us who want to develop a mix better attuned to our particular soil, Solomon tells us how to collect a soil sample, where to send it to for analysis, and how to interpret the results and use them to develop a mix tailored to remedy the particular pattern of deficiencies and excesses our own soil exhibits. I’ll be doing this and will report on what I learn, the mix I develop, and its effect on my garden throughout the season. I encourage other gardeners to read the book and try the updated recipe (or, if you want a personalized mix, have your soil tested and develop your own mix and try that). Let me know how it works for you. I’ll be interested in comparing results with those of you who have the more clayey soil typical of most of the St. Louis region rather than the silt-loam loess soil that I have.