After a few days of beautiful spring weather, it looks like we are expecting one more wintry-ish round of weather. I’m seeing predicted lows of 33, 29, and 30 for Tuesday, Wednesday, and Thursday nights respectively. Because it has been a fairly cold (and getting later) spring, there isn’t a whole lot that needs protection. Most of your cool season garden vegetables shouldn’t have any trouble tolerating those temperatures unless they have just been transplanted outside. Most fruit trees (with the possible exception of apricots and some peaches, perhaps) are not in full bloom yet. I suppose they might be with two more days of warm weather.
If you have some blooming plants or vegetables that you want or need to protect from freezing temperatures, here is a great article from The Garden Professors blog about how to do that effectively (and why it works): Protecting Plants from Frost.
While heat is the biggest challenge when planting your fall garden, by the end of fall there is the challenge of cold weather. In an average year, the first light frost will usually occur in mid- to late October, although sometimes the first frost occurs sometime in November. A light frost, where the low temperature dips down to 30-32 degrees will not damage fall vegetables. The cold may even improve the color and flavor of the vegetables. Most fall vegetables will tolerate temperatures down to 28 degrees without significant damage. In fact, allowing exposure to below-freezing temperatures will often allow the plants to better adapt to the cold, increasing their hardiness to later cold weather.
On a cold morning before the temperature is back above freezing, your plants may look wilted and permanently damaged. However, by the time the temperature is back above 32 degrees, they will recover and continue growing. It is important not to harvest these fall vegetables until the temperatures are back above 32 degrees and the plants have naturally recovered from the frost.
When low temperatures dip below the mid-to upper 20s, it will be necessary to protect semi-hardy fall vegetables with a light row cover to minimize damage on those vegetables. Some particularly hardy vegetables, such as spinach and kale, will not need extra protection until the low temperature is near 20 degrees.
It is usually best to remove the row covers during the day to allow the sun to warm the soil more efficiently when we are still getting intermittent frosts. As we get later into the year, leaving the row covers on may help create a mini “greenhouse effect” and prolong your growing season once we are regularly dipping into the 20s overnight.
According to the forecast, we’re supposed to get our first frost/freeze in the Wichita area tonight. I’m seeing 30 degrees as the projected low. Of course, I’m always skeptical of that first freeze until it actually happens. However, we have to assume it will happen. So, what do you do about your garden vegetables?
Here are my thoughts:
- Given the projected highs and lows for the next couple weeks, I don’t really see any point in trying to keep warm season vegetables/herbs going. My choice would be to pick whatever I can and let the rest go. It isn’t going to be warm enough in the next week to push many more of those tomatoes and peppers to mature and ripen.
- If you really want to try to keep warm weather loving plants alive, you will want to cover them. You might also consider pulling back any organic mulch (straw, grass, leaves) from around the plants so that the sun can keep that soil as warm as possible going into the cold nights.
- Cool weather loving vegetables and herbs (lettuce, spinach, root vegetables, thyme, sage, strawberries, broccoli, etc) shouldn’t need to be covered with this projected low temperature. They may sustain very minimal damage on the edges of older leaves, but they won’t be killed, and you will have little loss in edible value. Many of these vegetables get sweeter after a couple freezes. If you cover these vegetables tonight, be aware that they will need to be uncovered, because they will get too warm under a row cover most days yet. Read the rest of this entry