Master Gardener: Squeeze in some more crops this year with a fall garden

Many of us feel your pain. Let’s face it. As much as we love gardening, it’s just hard to get excited about working in our gardens when the heat index is approaching 110 degrees. But now that we see cooler days on the horizon, it’s time for us to get out there and plant some seeds.

The event that brings about the end of our garden season is the first freeze date of the year. In Oklahoma, Nov. 15 is the average first freeze day. But averages exist in the times between actual first freeze dates each year. It’s kind of like how the average family has .78 kids.

As you might remember, last year our vegetable gardening days came to an abrupt halt in mid-October. That’s about a month early. That could happen again, or that first freeze date could be closer to the average, or it could be later. We’ll just have to wait and find out. For those of us planting seeds now, the freeze will determine whether we get crops or not, but if gardeners are anything, we are gamblers. Here’s why that first freeze date is important in helping determine what we would plant right now. It’s all about “days to harvest.”

Assuming we plant in early September and assuming the first freeze date will be close to Nov. 15, we’ve got about 75 days of growing season left. There are some exceptions, and we’ll talk about those later.

Fall crops can be grouped into three categories: tender vegetables, semi-hardy vegetables and hardy vegetables. Tender vegetables would be those vegetables that don’t handle frosts well at all, meaning, at the first frost, they are done. Tender vegetables would include beans, cucumbers, eggplant, peppers, tomatoes, etc.

Semi-hardy vegetables are those that can tolerate a light frost here and there while continuing to grow. Semi-hardy vegetables would include beets, broccoli, cabbage, carrots, cauliflower, collards, kale, parsnips and radish. And hardy vegetables include something like garlic, which you plant in the fall as an over-wintering crop.

So, here’s the challenge with planting now. Bush beans have a days-to-harvest of 50 to 60 days, so you should be good trying to squeeze one more crop of beans out of the season. But something like peppers need 90 to 100 days, which will put you squarely past the average freeze date of Nov. 15.

Vegetables in the semi-hardy category might be a better bet because as I mentioned, they can survive a few frosts to keep growing. For example, beets have a days-to-harvest to 60 to 70 days, broccoli days-to-harvest of 70-80 days, cauliflower — 70-80 days. With vegetables such as these, you have a much better chance of getting a harvest in spite of the fact we might have another early freeze.

Other than selecting the proper vegetables to plant, there’s not much difference in your growing strategies. First up, if you haven’t gotten a soil test, now would be a good time. This way you’ll know exactly how to supplement your soil nutrients to help make your garden more successful.

Then, if you’re like me, you are thinking of how you might improve your irrigation system so that it would be more “hands-off.” By “hands-off,” I mean installing some sort of drip irrigation system that can be turned on and walked away from. Drip irrigation is a great way to not only lower the number of hours you spend in the garden but to also ensure your plants are getting a good drink of water in a way that promotes deep root growth. Since drip irrigation delivers the water in a slow drip format, this allows the water to sink deeper into the ground. Water availability deeper in the ground encourages roots to grow deep to access their moisture needs rather than being surface feeders, if your will. Surface-feeding roots will dry out sooner and need more frequent watering.

Also, if you didn’t apply mulch, now would be a good time to get some mulch for your garden. Tulsans have a great source for free mulch at our Greenwaste site. However, due to the storms back in June, they are too busy processing tree debris to make free mulch available to the public. So, you’ll need to either make your own with mulched leaves from your landscape or purchase one of the various mulches that are available commercially.

Mulch is probably one of the best things you can do for your garden in that it helps to minimize weeds, it helps the soil retain moisture, and helps to regulate soil temperatures.

During our recent days of extreme heat warnings, I was watching the soil temperature information at mesonet.org. When the days were hot like that, 4-inch bare soil temperatures were reaching 105 degrees. With soil temps this high, you can see how it would be hard to keep your soil hydrated. However, with a good layer of mulch, these soil temperatures can be 20 to 30 degrees cooler with less variability during the day.

Bottom line, if you feel like planting some seeds and seeing how it works out, now is a good time to plant certain crops. We have a fact sheet from OSU on our website that gives you detailed information on which crops you can plant in the fall. Just go to tulsamastergardeners.org and click on the Lawn and Garden Help Section. You’ll find it there. See you in the garden!