Believe it or not, we are only a couple of weeks away from being able to start planting for our spring vegetable garden. If you happen to have a cold frame (we’ve talked about this before) you can start even sooner since the cold frame helps concentrate heat on your plants and the soil. But, even without a cold frame, it’s almost time to plant some of our crops.

Cool season vegetables may be a new term for some, so when I say something is a cool season vegetable, it means that this plant does better in cooler temperatures as compared to our hot summers. Cool season vegetables will either go to seed too quick or just give it up in hot weather. Plus, many of them have some degree of cold hardiness built in. Now this doesn’t mean they will survive if we get sustained temperatures in the 20s or below, but a little cold here and there won’t destroy them.

Here’s some of the crops considered cool season vegetables in our area: beets, broccoli, cabbage, carrots, cauliflower, Swiss chard, lettuce, onions, peas, potatoes, radish, rhubarb, spinach, and turnips. Some of these do better when planted as plants while others will do ok when planted as seeds. Those you should plant as plants include broccoli, cabbage, cauliflower, and onions. I’ve already started the seeds indoors for cabbage and broccoli for our Master Gardener Seed to Supper Farm so they will be ready to go in the ground mid-February-ish. Our onion sets are also on order to be ready to plant about that same time.

Onions are available in what are called “sets.” You can look at onion sets as immature plants. They were grown from seed by the vendor and are able to be re-planted.

Cool season crops can be grouped into 3 different groups: hardy, semi-hardy, and tender. Hardy plants can stand short periods of freezing temperatures. Semi-hardy can handle a light frost but will be damaged with a late frost or freeze while the tender ones will be damaged with a light frost. Here’s a list of those plants considered hardy: broccoli, cabbage, onions, radish, rhubarb, spinach, and turnips. Semi-hardy would include beets, carrots, cauliflower, lettuce, and potatoes.

Planting cool season crops will require that you pay attention to the weather and make a judgement call as to whether you will need to cover your crop in the midst of a cold snap or not.

For those wanting to feel a little more secure about your cool season crop’s longevity, you can invest in some sort of protection strategy. For starters, you can purchase frost cloth from the garden center. A single layer of frost cloth over your plants can keep them about 5 to 8 degrees warmer than without frost cloth. On a very cold night, you can utilize a couple of layers. This frost cloth can be draped over a half-circle hoop above the plants or just supported to keep it from damaging the plants.

You can also build what is called a cold frame. A cold frame would be some sort of structure with a glass or clear plastic lid that covers your cool season plants. With a cold frame, you can start your outdoor vegetables earlier, since it is kind of a mini greenhouse. Since it’s usually about 5 to 10 degrees warmer under a cold frame, you can not only start your vegetables earlier in the spring, but you can continue to grow them later in the fall growing season as well. Yes, cool season crops are good in both the spring and fall.

As we progress in the growing season, mid-March will be the time to plant potatoes. St. Patrick’s Day is a good marker day on which to plant potatoes, but depending on the weather, you might be able to start them earlier.

Potatoes are a fairly easy crop to grow and typically produce a good harvest, and potatoes store really well in the refrigerator. I enjoy planting potatoes with our granddaughters. I tend to grow our potatoes at home in what is called a grow bag. Grow bags are made of a felt like material and come in a variety of sizes. The advantage to growing potatoes in grow bags is that you can roll down the sides to where it is only about 6” deep and plant your seed potatoes. Then, as the plants grow, you can roll the sides up a bit and add more soil. You can continue to do this as they grow until you reach close to the top of the bag. This will increase your harvest by encouraging potatoes to develop all along that buried stem.

I mentioned seed potatoes. Seed potatoes are different than the potatoes you might purchase at the grocery store in that they are grown specifically to be used as seed potatoes. Once you get your seed potatoes, you can divide your potatoes into 2 or 3 pieces with each piece containing an eye ( a small sprout). Using potatoes from the grocery store can be problematic since they are oftentimes treated to prevent the potatoes from developing eyes, since potatoes with eyes don’t sell as well as potatoes without. Anyway, there’s lots more to talk about here but if you would like more information on growing vegetables, stay tuned for future articles or visit our website (www.tulsamastergardeners.org), click on Lawn and Garden Help and then Vegetables. Or, we still have a few seats for our March 22 class on growing vegetables. See you in the garden!

You can get answers to all your gardening questions by calling the Tulsa Master Gardeners Help Line at 918-746-3701, dropping by our Diagnostic Center at 4116 E. 15th Street, or by emailing us at mg@tulsamastergardeners.org. Photo: OSU Ag. Comm.