Fall Planting

Can I plant a fall garden in Oklahoma?

Absolutely! You just need to know what to plant and when.

Think leafy greens and roots. These crops thrive in the cooling temperatures of autumn. They will grow more slowly than spring crops, but their flavor improves with cold temps. Plus, bug pressure almost disappears as it gets colder. And you don’t have to water as often. I love gardening in the fall!

From August to early October, I planting:

broadcast seed or plant seedlings. As we get into late fall and early winter, plan to give them some protection; plant under hoops (see article below) with row cover, or use a cold frame. Harvest baby greens as cut-and-come-again.

broadcast seed or plant seedlings. Arugula is a fast grower (start harvesting baby leaves in 4-6 weeks from seed, quicker from transplants) and has greater cold tolerance than lettuce. If you want it to keep growing thru mid-winter, use row cover.

Spicy Greens & Asian Greens:
all those lovely mizunas, mustard greens, bok choy & tatsoi add texture and color to salads. Plus they have such pretty names! (Golden Frills Mizuna, Garnet Giant, Ruby Streaks… Check out this page at Johnnys Seeds for some gardening eye candy.) I usually add a handful of them to a bowl of lettuce, which is just the right amount of “kick” for me. Moderately cold hardy outside. Direct seed or transplant.

winner of the most-cold-hardy-greens contest! I learned this by accident many years ago, when we planted some fall spinach, forgot about it when winter arrived, and early the next spring discovered it growing happily & vigorously. Yaaaay for plants that take care of themselves! Unlike most seeds, spinach needs cool soil in order to germinate. It just won’t sprout if you seed it in early fall while the soil is still warm. You can get around that by soaking spinach seed in a jar overnight, then drain the water and put the covered jar in the frig for a week or ten days. The seeds will break dormancy in the cold, wet environment; once you see a tiny bit of white root starting to break thru the seed coat, take the jar out of the frig and plant the seeds. You can also direct seed in late September/early October for early spring harvest. Spinach does need water if we have a winter dry spell (common here) and while it will usually survive without row cover, you’ll get more growth if you give it some protection when the cold weather settles in.

runner-up for cold-hardiness. Kale gets sweeter as it gets colder. Direct seed or transplant. Red Russian (my favorite) is quite tender and moderately cold hardy; it will go thru the winter with row cover and occasional watering. The green curly type of kale (Winterbor, Siberian) is more cold hardy and really needs a frost or two to sweeten up. Harvest the outer leaves throughout the fall/winter, and wait for the inner leaves to mature to harvest size.

one step away from instant gratification — 30 days from seed to harvest, a little longer as we get later into fall. Radishes grown in chilly weather are MUCH sweeter than what you are probably used to eating. I have stood by the kitchen counter popping ‘Pink Beauty’ radishes in my mouth like candy while intending to chop them up for salad. (This from someone who used to hate radishes.) Row cover will extend your radish harvest into early winter. The more fertile your soil, the sweeter will be your radishes.

Daikon Radishes:
not fully appreciated in this country, but well worth an introduction! There are several varieties of daikon that are so pretty, I just can’t resist them. ‘Watermelon’ or ‘Red Meat’ has green/white skin & a red interior. Green Luobo’ has white skin and a green interior, and KN-Bravo is purple inside & out. Slice all of these like coins; add to salads or serve on a platter with hummus or dip – gorgeous! Seed by early-mid September as they mature more slowly than regular radishes.

carrots are at their sweetest, more glorious state when seeded in fall and harvested in early spring. The cold temps turn their starches into sugars (the plant version of anti-freeze) and they are a buried treasure to dig up in March. Plant in late September or the first week of October (no later!) as they need time to sprout and grow while there is still enough day length. They’ll keep growing, very slowly, all thru fall and winter. Carrots are remarkably cold hardy; the root is in the ground and protected, and the greens can freeze and thaw and be ok. In a super cold winter, I’ll use row cover on them, but I usually don’t bother. Two tricks with carrots: plant in loose soil (make it easy for those roots to grow down) and water the seeds religiously while germinating. Carrot seed can take a couple weeks to sprout, longer in cool soil; they need to stay moist the whole time, and they’re unforgiving about drying out. For fall-harvested carrots, direct seed in late August or early September and water fervently while germinating.

Baby turnips:
a revelation for those of us who (thought we) hated turnips. AKA salad turnips, these babies are harvested at golf ball size or smaller, and taste like turnips would taste if turnips tasted good. Direct seed late August to early October; you can thin them out and eat some marble sized babies while you’re waiting for the rest of them to size up to 1-2” diameter. They can be harvested fall to early spring. Cook the greens while you’re at it. Cold hardy. My favorite variety is ‘Hakurei.’ I could spend all afternoon talking to you about baby turnips, they are so unexpectedly tasty, and so satisfying to grow. Try them, please.

true confessions – I am terrible at growing beets. I don’t know why. I have friends who are good at growing them! Best to plant them in late August or early September for a fall harvest. But if you just want beet greens, you can seed until early October, and use row cover to extend the harvest.

Green onions:
I like to start green onion seeds in pots in July or August, and transplant the little seedlings outside in September or October. Green onions are surprisingly cold hardy; if transplanted in early October, they’ll overwinter and you can harvest big green onions in early spring.

Broccoli, Cauliflower, Cabbage & Brussels Sprouts:

These illustrious members of the brassica family all share a preference for cool weather. If you’ve had poor success growing them in the spring, try a fall crop – it’s much easier! The seedlings are generally fairly heat tolerant, but the plants need cooler weather as they mature or they’ll bolt and get bitter. Plant in mid-August (yes, really!) in full sun with fertile soil, with weekly rain or watering; we’re aiming for rapid growth so that they’re ready to harvest in mid-late October before the first fall freeze. Brussels sprouts are much more cold-hardy than the other brassicas, and also take longer to mature; I usually harvest them in December/January. ‘Arcadia’ is a variety of broccoli that is unusually winter hardy; I have transplanted it in September with winter protection under hoops and plastic row cover, and harvested it in mid-winter.


What’s this about hoops & row covers?

Hoops & row covers are what makes my fall/winter garden a happy & productive enterprise. The photos show our low tunnels made with row cover over EMT conduit hoops. Take a look at that lettuce growing in the middle of February!

Row cover is a spun polyester fabric that can be used and re-used, placed directly over a growing bed or over hoops. It creates a little micro-environment with wind protection, cold protection (2 to 8 degrees) and increased humidity. In my experience, the results are greater than the sum of the parts; it REALLY works! Row cover is not biodegradable, and I don’t know of any place here to recycle it, so I use it carefully and re-use it as many times as possible.

I order my row cover from Johnnys or Farmers Friend or other garden/seed supply companies. The big box hardware stores sometimes have it in stock. Someone locally really needs to decide to carry it. I usually get the .6 ounce weight that allows 85% light transmission, or the 1 ounce weight with 70% light transmission. The heavier the weight, the greater the cold protection, and the sturdier it is, but the less light transmission.

In really cold weather, I’ll sometimes cover my hoops with clear plastic, but plastic has to be opened up every morning before the sun heats up the inside of the low tunnels (think of a closed car on a sunny winter day) and that gets to be a hassle. But useful for seriously cold weather.

Hoops: you can make wire hoops out of galvanized #9 wire (a bit floppy, but they work), or use EMT conduit for very sturdy hoops that will last a lifetime. For EMT conduit, get the 1/2″ size in 10′ lengths at the hardware store, about $3.50 each. You have to have a hoop bender for the conduit. Thanks to a couple generous donors, CommonWealth Urban Farms has two hoop benders, available to the general public for use on-site. Buy your EMT, email me to set up a time, then come over and we’ll show you how to bend your hoops. We can help you bend hoops that are 3′, 4′, 5′ or 6′ wide, depending on the width of your garden beds. It’s easy, fast and makes you feel like you’re a heck of a gardener.

Johnnys Seeds has an excellent handout on using EMT conduit to make low tunnels. Read it! It will save you from making a bundle of mistakes.

Cold frames & solar cones are also excellent for season extension, although they take a bit more effort to build.

For Garden Geeks:
An explanation of day length and how it affects fall/winter gardens…

Big thanks to Eliot Coleman & his superb books* for introducing me to this concept. We all know that temperature affects plant growth, but day length has an equal, sometimes greater effect. Our longest days are from mid-March to mid-September (spring solstice to fall solstice); combined with warm temperatures, we get the fastest plant growth during this time. As the days shorten and temps cool down in the fall, plants keep growing but they grow increasingly more slowly.

However, when day length shortens to less than 10 hours, plants essentially stop growing. They don’t die, they just don’t put on much new growth. Eliot calls this dark period the Persephone months. The trick is to have mature plants by then that can be harvested, and not to expect new growth until day length resumes 10 hours and more.

Happily, in central Oklahoma, that window is only from November 27 to January 14th. But because January tends to be a cold month, I often figure Thanksgiving to Valentines Day as the “just hanging out but not growing” period.

Even if we do have balmy weather in January (it happens here sometimes!), my dear lettuce plants are still going to grow slowly because we have less sunlight at that point. And winter days are often overcast.

Combine low tunnels (hoops & row covers) with an understanding of the effect of day length on plant growth, and you can be a successful winter gardener!

*The New Organic Grower, Four Season Harvest, The Winter Harvest Handbook. Available thru our metro library system.