Spring frost advisory means some plants may get nipped
With recent warnings about potential frost in the news, now is a good time to remind gardeners that on average the last expected frost in southwest Missouri was April 17.
“It really is best to wait until the frost date has passed to plant,” said Patrick Byers, a horticulture specialist with University of Missouri Extension. “Especially with flowers, some folks will wait until May 1, which is typically our last frost date.”
A heavy April frost can damage foliage on annuals, perennials and trees in the yard as well as vegetables in the garden.
Homeowners can protect vulnerable plants with protective covers at night. Just remember, freezes can vary across local terrain. Low temperatures can vary by more than 10 degrees from the bottom of a valley to a nearby hilltop. Urban areas tend to be warmer than rural areas.
What type of damage can occur with a frost? Flowers are often the tenderest part of a plant, and the first to be damaged by frost. This is certainly the case with strawberries, peaches and apples.
“I get lots of calls from gardeners wanting to know what can be done to deal with frost,” Byers said. “There are three things. First and foremost, plant at the proper time to avoid most frost. Second, cover plants with row cover or other protective layers. Third, pull back mulches and moisten the soil.”
Do not use plastic to cover plants. Always use paper or bed sheets or something similar to keep them a little bit warmer.
Easter freeze of 2007
The harm in 2007 came as a result of the record breaking warm temperatures in late March followed by record lows April 4-9. Because of the earlier warm weather, plants were fully activated and not prepared for freezing cold temperatures.
“There is no way to know how the remainder of the spring is going to go weather-wise,” Byers said. “The weather in the winter of 2007 had been the third warmest on record and then along came the devastating week of the Easter freeze.”
The Easter freeze of 2007 was when several days of record cold temperatures, from April 4 to 9, damaged trees and fruit crops, which had leafed out and bloomed early.
In 2007, MU Extension horticulture specialists advised patience. In most cases, it took a couple of weeks to really determine how much damage occurred to the plants.
Most perennials were able to overcome problems from the freeze at that time and trees did rebloom.
“Gardeners seem by nature to be optimistic risk takers. When the weather warms up, even if it is in February, some gardeners go ahead and plant,” Byers said. “That is okay if you don’t mind needing to replant if the weather turns cold.”
The best rule is to follow the advice given in MU Extension’s vegetable planting calendar. The calendar gives lots of information on when to plant, how much to plant per person, and suggests varieties that grow well in this area.
This guide is available at extension.missouri.edu/p/g6201. It will also be available at the nearest county Extension center or at the MU Extension’s Master Gardeners office in the Botanical Center at Nathaniel Greene Park, 2400 S Scenic, or telephone 417-881-8909.