At any rate, the weather is always a challenge to the gardener, and this time of the year can be frustrating. Our flowering trees have been spectacular up to now with the saucer magnolia bloom the best I can remember in years.
They made it through without damage from a freeze thus far – that is until this past week. We had two nights dipping down into the 20s causing damage to flowers, the most sensitive to freezing temperatures.
I haven’t heard a report yet from my fruit-growers, so I am not sure how they fared. As flower buds begin to swell, eventually opening, they are susceptible to freezing temperatures.
For instance, peach buds at the bud swell stage have a 10% kill rate if the temperatures drop to 18°F. As they open and become more exposed to the environment, they are more susceptible.
Peaches with buds just showing the first sign of pink color will have 10% kill at 25°F. If they are in full bloom, there is a 90% kill when it drops to 24°F.
Thus, the stage of growth and the temperatures are critical when it comes to freeze or frost injury. My asparagus is just popping up with some spears about four inches tall. The drop to 24°F on Tuesday morning turned those above ground to mush.
Fortunately, the spears that are yet to come and have not popped above ground won’t be injured, so I will still have asparagus.
There are precautions that many fruit growers take to mitigate cold damage in the spring. One of those is to locate the orchard or strawberry patch in an area that is on higher ground. Frost settles in lower areas first.
Selecting the right cultivar and variety is also important. I did this with my saucer magnolia. I selected a cultivar named ‘Ann’ because it blooms just a little bit later in April, many times (though not all), avoiding a hard freeze.
Orchard heaters may be helpful but can be costly. Wind machines to keep the air stirred up are also utilized. A simple solution that can be helpful is to have ground cover on the orchard floor.
Grass or other vegetation can absorb heat during the day and give off more heat at night than bare soil. Moist soil at night is also warmer.
There are ways homeowners can mitigate the cold. One technique is to cover the plants in question overnight. Don’t cover with plastic as this holds cold air under the plastic. Use an old sheet or purchase frost protection covers developed for this purpose.
Hang in there, it’s that time of year.
Pamela Corle-Bennett is the state master gardener volunteer coordinator and horticulture educator for Ohio State University Extension. Contact her by email at bennett.27@osu.edu.
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