Successful strategies for fall planting in ColoradoJul 24, 2023 02:36PM ● By Bryan Reed
As harvest hits full stride, now is the time to get your fall and winter gardens going. In our climate, we should be pulling food out of our gardens at least until Christmas. I’ve harvested winter greens and roots all winter long with the help of some season extension devices.
As the days shorten and temperatures cool, many crops that bolt in the summer heat can be planted now. Spinach, cilantro, lettuces, arugula, Asian greens and peas are great crops to plant from seed. It’s often easy to pick a space where beans or root crops used to be and plant fall crops there.
Broccoli and cauliflower are fall crops that can thrive in cooler temperatures, but they need space to grow and head out when they mature. When it’s warm, take advantage of the shade from established crops and plant seeds in between those plants. Kale, chard and mustard appreciate how the shading tomatoes and peppers keep the soil moist, which helps them germinate even when it’s still hot and dry.
When frost comes in October, the summer crops die back and the cold-tolerant fall crops gain all the available sunlight they need to thrive well into December. Short-season root crops like radishes, green onions and baby turnips (hakurei) are also great candidates for a fall harvest when conveniently planted in between existing summer crops.
FALL COVER CROPS
In large acreage, we plant winter wheat, barley and rye, then freeze back the tops which lay down to insulate the soil and protect the roots from subfreezing temperatures and then grow back in early spring for a late spring harvest.
Obviously, there’s economic gain from producing crops on soil that’s being paid for all year long. Just as important are the improvements in soil health from the living roots in the ground that feed soil microbes, earthworms and decomposer insects.
Fall cover crops in the garden also protect the soil from wind and water erosion while creating a natural snow catchment system to keep moisture in your garden.
For homeowners, annual crops like buckwheat, oats, radishes, peas, mustards and beans can be planted now and still aid in cycling nutrients in the soil, fixing nitrogen and setting roots, which become organic matter and thus subsoil food for next year’s crops.
Greencover Seeds offers a variety of crops that make wonderful fall cover crops, many of which can mature and be eaten before October. Learn more at greencoverseed.com.
TIMING IS EVERYTHING
When planning out your winter garden, the first thing to consider is the timing of planting crops. We peaked daylight hours on June 21. On August 20, we hit 13.5 hours of daylight and then we’re on our way to 12 hours on September 26.
Seed packets list the days to maturity based on spring daylight heading into summer. Because we lose hours in the fall and winter, it extends the days to maturity by 25-50%.
This means that arugula planted in May can be harvested in 45 days, a September 5 planting can take 55 days and an October 5 planting can take 75 days because of fewer daylight hours and cooler temperatures.
So in August we need to plant crops so that they are of good size with deep roots to withstand our fall conditions. Beets and short- season carrots must be planted soon in order for them to mature properly. Waiting until September is too late for them to thrive.
Another part of the strategy is providing some level of protection from cold winds and overnight temperatures. This can be as simple as putting bed sheets over tomato cages and sitting them on the corners of the garden each night. I like to place straw bales around the edges and lay a sliding glass door on top as a mini greenhouse.
The fall crops I mentioned at the beginning of this article can take a hard frost. A thick blanket can provide 5-10 degrees of protection so overnight lows of 18-20 degrees can be tolerated. Wire hoops can be placed over the winter crops and 6 mil plastic (or thicker) can provide protection from the cold and can capture daytime sun to warm the soil.
Planted turnips, carrots, beets and rutabagas can mature enough so that when their tops get frozen back, they can still be mulched with dry leaves and covered with an anchored tarp so they stay protected from deep freezes. Every couple weeks, pull back the tarp, rake back the leaves and harvest a couple pounds for the refrigerator.
Optimal planting dates are August 10-24 and September 6-20. For a successful winter garden, one strategy is to plant seeds around August 10, then a second planting by the 24 and a third planting around September 6. This will ensure strong plants before real winter weather sets in.
Send your gardening questions to Bryan in care of the BEACON, or email him at [email protected]