The Chatelaine's Keys

Sharon July 7th, 2009

Every year it happens to some folks - for whatever reason, the garden either doesn’t get in early enough or doesn’t do well.  We get to the beginning of July and we’re left with a panicky sort of feeling that it is too late to do anything about it. Or maybe you are having a good year, and what you mostly want is to keep that going as long as possible - sure, you are preserving and ready to root cellar, but your favorite foods are the ones that come fresh from the garden and you want to know how long you can keep that going.

Good - because the answer is almost certainly “longer than you think.”  I live in central upstate New York, technically zone 5, but really in practical terms closer to zone 4.  Our low temperature was -28 degrees one year, and our last frost has been as late as June 1 and our first has been as early as August 30 (unusual, our official dates are May 20 and October 7, and in the 8 years I’ve been here, last frost has come as early as April 23rd and as late as June 1, and as early as August 1 and as late as October 31, so there’s a pretty big range) and yet I’ve managed in various years (I can’t do it all every year) to overwinter leeks, spinach, scallions, kale, collards, arugula and of course, the unkillable parsnips absolutely without any protection.

With protection, the range of possible crops expands a considerable amount, with the right choice of varieties.  In a good year, I’m still harvesting things at Chanukah, and I can have more food ready to pick on my unheated porch by March.  With more protection, other solutions, I could go through the winter - we just haven’t made the capital investments yet.  But while not everyone will be able to do everything I can, most of us will be able to extend our season in some measure.

The two major factors are these - light and temperature. I think most of us think that temperature is what matters most, and for most warm season annuals, including many of our favorite annual garden crops, it is.  We’ve all come out to the garden to see almost everything blackened with frost, and known that it was basically all over.  A garden composed heavily of the most popular crops, particularly a garden planted one time in the spring, won’t have a lot to offer in the fall.

That doesn’t mean that warm season crops can’t be part of your fall garden plan - fast growing tender annuals can and should be part of your fall garden - for example, I plant my main crop of pickling cucumbers and bush beans in late June or early July - the plants will mature before frost, just as the first crop is petering out, but more importantly, it means I don’t have spend as much time over a canning kettle in July and August - pushing harvests forwards means that I can can in late September when the heat is welcome.

What you need to know about these crops is that it will generally take a little longer for them to mature if planted after the equinox than before - declining light means that even though the days are long, many of the plants will mature a bit more slowly - so add some time to your growing season.  Usually by mid-September in my zone (later if you are in southern zone, cooler in a northern one), most plants begin to grow very slowly, if at all - they will still mature fruit, but they aren’t setting more blossoms or growing bigger, so if you want, say, to plant 55 day bush beans, you’ll want to get them in 55 days before mid-September.  Some of this involves guess work, and experimentation - it never hurts to take a chance.

Warm season crops that can be planted in my zone as late as early to mid July include zucchini and summer squash, shell beans, bush beans, cucumbers and basil.  If you live in zone 6 or above, you still might be able to do short season winter squash or melons, even.  Remember, even after a frost, you will still be able to keep things for a few more weeks - so, for example, if you plant cucumbers now, and mature a crop in September, you will be eating fresh cucumbers probably until a week or two after your frost - I find that it makes a big difference to extend one’s season by even a couple of weeks into the fall.

The category of crops that will do best for most of us as the weather gets colder, though are mostly greens and roots.  Almost all root crops are much more hardy than crops where we eat the aerial parts, which makes sense, because they are covered with a nice layer of insulating dirt.  Many of them are also hardy in their own right - that is, they can take a lot of cold.  Carrots, parsnips, leeks, turnips, salsify, scorzonera, celeriac, beets, parsley root, kohlrabi - all of these have varying degrees of cold hardiness.  Many of them are cold hardy biennials - you eat the root the first year, usually, but if you leave them in the ground, depending on how cold it gets, they will come back and set seed next year. 

The other category of vegetable that does well in cold weather is many greens - brassicas, lettuces, green herbs and many asian greens.  Many of these, particularly the brassicas, have a wonderful feature where the starches in them convert to sugar after a hard frost or two.  If you’ve ever eaten cabbage or kale or brussels sprouts after a frost, you’ll know the difference is night and day - they are nice enough vegetables during the warm season, but in they are spectacular.  This is true of most roots as well - your beets and carrots will be sweeter after the ground freezes a bit, your turnips will be tastier.  Even your lettuces have a crisp sweet taste.  These crops really come into their own after the other stuff is done with.

Thus, a fall and winter garden will be heavy on greens and roots.  Not all of these are equally cold hardy - beets and carrots, without heavy protection, for example, will simply rot in my climate.  Yes, they can take some frost, but not a winter’s worth.  Parsnips will barely notice winter.  Broccoli kicks out well before cabbage, and brussels sprouts will stand longer still.  Getting to know your veggies will help you get the most out of them.

But back to light and temperature - daylight hours may matter more than cold here - at least if you are speaking of cold hardy vegetables.  The plants start to shut down growth for the winter as the day length gets shorter. That means you’ll want to put your winter crops in your sunniest spot - if you get part shade, save that for summer lettuces or greens, or for kale and collards you will keep going all summer.  Don’t plant you fall garden there, because it may not mature.  And maturity matters - very small plants are a lot less cold hardy than larger, developed ones.  You need to figure out when things stop growing at your light level - this may require you talking to your local cooperative extension, and it will probably involve some experimentation on your part.

What Eliot Coleman found when he began his project (he has the two definitive books on this subject _The Four Season Harvest_ and a new one _The Winter Harvest Handbook_) is that if you choose the right crops and master the timing, light ends up being more important than temperature.  And I think that’s particularly true if you are growing under cover as he is - he loses some light to filtration, and his temperatures, especially in the fall, are more moderate than mine are.  If you are simply trying to extend your season as long as possible in an open garden, you’ll find that temperature is trickier, because a really deep, hard extended cold spell will knock out a lot of crops.  This is, of course, an argument for creating protected growing spaces, but since many of us may not be able to make large capital investments in hoophouses and other projects, it is also an argument for, well, being realistic about what you will accomplish. 

To give a sense of the variation involved, let’s consider two consecutive years of my fall gardens - 2007 and 2008.  2007 was an unusually warm fall - the first hard frost actually came on Halloween, the latest we’ve ever seen it.  The winter was also unusually mild, at least in the first portion of it.  I was able to pick turnips and leeks out of unfrozen ground with only a moderate straw mulch in early January.  Spinach and kale overwintered uncovered for me, and we ate the last of the ripening picked-green tomatoes at Chanukah.

Last year, frost came early, a light one in late September, then a heavier frost in early October.  At the end of October, we had heavy snow and four days in a row in the 20s.  That pretty much ended the run of the broccoli, and other crops I’ve often been able to enjoy well past Thanksgiving.  One of the realities of growing this way is you really don’t know how long a season you will have - on the other hand, the only way to get the best for the longest is to experiment.

We will talk more about growing with cover as we go along, but what you mostly need to know is this - that fall and winter gardening are about experimentation.  You can get advice from me or others who are doing it, you can read Eliot Coleman and get advice from agricultural extension, but most of what you will need to know you will have to learn in some way involves experimentation - if you grew up somewhere where everyone put in a garden once a year, and that was it, you will find that this is far less certain than waiting for the weekend after you last frost date, planting, and then harvesting it all in September.  But that’s not bad - it also means you can eat green stuff for part or all of the year, fresh from your garden - often better, tastier green stuff than some of what’s available to you in the summer.  This is worth some effort.

 Sharon

• cool season gardening
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