We experienced some crazy weather changes this past Thanksgiving Day. In the late morning, temperatures were in the high-70s (degree Farenheit). Yet as the afternoon wore on into evening, temperature dropped approximately 30 degrees in a span of 3-4 hours. Those kinds of drop cannot be good for plants. Within a week, the Plant Clinic were seeing queries about damaged with some cold tolerant plants such as mustards greens, broccoli and cauliflower. People wondered what happened their plants that are supposed to thrive in cooler temperature. Unfortunately, even those cold tolerant plants will show freezing and/or cold damage when expose to such extreme swings in temperature. The response and damage symptoms observed due to the temperature swing can vary greatly among the different types of plants. Furthermore, topography of the growing area may buffer OR increase the temperature change. Damage symptoms that are seen can be the typical interveinal necrosis (giving a burnt appearance). On plant that tolerated the temperature change better may result in crinkly leaf form, where the cold may have interrupted growth on certain parts of the leaf.
Hopefully we won’t have too many “short period big swings” in temperature. A few strategies to remember this winter season in Texas, as we can still see some warm days is to provide some protection to the plants when such temperature swings are forecasted. Moving plants to protected areas and/or placing fabric/cloth over the plants can help to reduce damage. Proper irrigation prior to ensure that the plants are not under water stress will also help the plant to withstand possible temperature change damage.
Good luck and Happy Gardening.