Monday, October 17, 2011

Growing Winter Cover Crops

Depending on your climate you may be able to grow crops all winter. Here's the snag. For some you're going to need a greenhouse, and for others you should have well-established and cold tolerant plants already in the garden. Things like kale, cabbage, leeks and some root crops. We also keep spinach and lettuce late into the year. Eliot Coleman has a book about using an unheated greenhouse year round called the Year Round Harvest (I think) but it isn't going to work for us here as it's simply too cold at times of the year. Instead we'll use a greenhouse to get earlier crops in and extend the season later too. How late though depends on how long and cold it gets at any given time. The truth is that no matter what you do for your lettuce it's going to freeze and become mush at some point unless you invest in a heated greenhouse and that's not usually a feasible idea. Heating a greenhouse can be costly. However growing a few lettuce or some sprouts on a sunny window ledge inside the house may be an alternative. For people in countries with a less harsh climate you can of course grow various crops year round or in 2 seasons where the summer is too hot and you end up planting in spring and again in fall. Just look around you at what the other people are growing. And if you want to experiment then by all means do! You won't know if you can grow watermelon unless you try right? Maybe the reason a particular crop isn't grown near you is because nobody tried before or it's not economically feasible for big business. Well, we're not big businesses so we should grow the things that we like to eat, that will sell at market, and that are useful to us. Taking into account your soil, climate and pest load, choose suitable seed and see if it grows! My big experiment next year is peanuts. We have sandy soil at our house that's not good for lots of other things but might be good for peanuts so we'll see how it turns out.

Winter gardening for vegetables does require some planning and work in July and August when you are growing your seedlings and then transplanting them into their permanent locations before winter comes. It seems odd to be working for the winter when it's hot outside, but the roots need time to become established in the fair weather before the sunlight fades and the nights turn cold. Things like cabbage continue to grow and mature over the winter and are protected from freezing by producing sugars as a natural anti-freeze. That's why brussels sprouts which have had a frost taste so much nicer than the ones from California where it's always warmer. Peas grow well if they mature while it's cooler such as in Spring and again in fall. We grow lettuce and spinach until they get frozen and will use a straw mulch if frost is coming. It's not a big loss if we lose some and having fresh greens is always nice. As mentioned before, just try to grow a few inside. And check out your seed catalogues, they will likely have some veggies that are meant to be grown and left in the ground until needed or that mature over the winter or into early spring. In West Coast Seeds they're conveniently marked with a snowflake symbol.

So if you don't have your winter veggies in place this winter a write off? Absolutely NOT! There are still productive things you can do to improve soil structure and fertility and even to get a crop for next year. They are called cover crops and grains feature prominently. Oats planted in the fall will quickly green up and then die off when they freeze. They provide a cover for the ground preventing soil erosion and protecting seed beds from damaging heavy rains. They can help control pest problems, particularly nematodes, and they can provide forage for wild bird populations which will sometimes garner you gov't funding. By spring you just crimp it and plant through the mulch or chop it and turn it into the soil. Barley, wheat and rye provide slightly hardier crops and can be planted up until a few weeks before your frost date. Wheat, if the right variety, will die off at very cold temperatures only to burst forth with new green shoots in the spring and will yield you either grazing for livestock, green manure that can be turned into the soil while still immature or left to mature the seed heads and provide grains for your table and livestock. So think about it, doesn't it make sense to use the winter as a time to grow something hardy or to spend the time renewing the soil through green manures known commonly as cover crops. They're pretty well maintenance free and yet so very useful to organic gardeners. There are several books on this subject and courses available at Agricultural Extension last time I checked if you really want to get into the nitty gritty and chemistry of it all.

Cover crops of more variety can be grown in the spring, things like clover and buckwheat which bees love, but for now rye, oats, wheat...that's the way to go, especially here in Canada. No pests and diseases to worry about, just useful crops for the winter. And if you already don't feel like working outside then consider wheat grass. Sprouting wheat is easy, it's packed with nutrition and you can start a new batch every few days on your kitchen window sill to maintain a fresh supply. It's also cheering to look at something green and growing during the cold dark days ahead while you're standing there doing the dishes.

It's not just organic farmers who suddenly started using cover crops. Farmers for hundreds of years have known the benefits of crop rotation, having a grass ley (a year and a half rest for the fields and grazing for animals) and how to manage livestock to benefit the soil too. This isn't some new fangled 'out there' sort of idea. It works. Even commercial growers are using cover crops now and I'll admit that it's nice to not see bare fields all winter. Grape growers and orchards take advantage of their row systems to use cover crops that repel pests and provide nutrients for the trees and vines as well as a comfortable walkway. So if they can do it, so can you! Once a section of your garden is done for the year I encourage you to plant a cover crop and then not to worry about it again until spring. Every little bit of soil nutrition you can add naturally, built up over time, will benefit you with increased yields, healthier crops and less pest problems. Even raised beds benefit from a cover crop so don't think your patch is too small. My first cover crop was years ago. A cat we'd taken in peed on a sack of wheat I'd left lying around and not wanting to waste it I just broadcast all that wheat onto the patch for next years garden. Seeing that wheat green up even before the grass did was awesome! And it was easy to turn in with a tiller about a week before planting the early veggies. Here's some info from Iowa State University on a cover crop and manure application experiment they did. There's also an experimantal farm in England near where I grew up that has a long range experiment underway using various fertilizers (or no fertilizer in one case) on strips of land for over 100 years now. The aim is to monitor soil fertility in the long term to see what's sustainable and what is damaging to the environment. The more we understand about soil chemistry, the more observations they are able to record that benefit us growers and help us better manage the resources we have.

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