Waking Up To Spring
I recently heard something that sounded like a crash in the living room at 5:35 a.m. This always creates something of a dilemma. Do you wake up and investigate? Or do you take advantage of those 10 precious more minutes of sleep before the alarm goes off?
I find the situation usually resolves itself in this way: I lie in bed for 7 minutes trying to sleep but can't, then cuss and swear for another full minute. After determining that all is well, I start swearing all over again. And then the alarm I forgot to switch off in the bedroom sounds.
Plants in the late winter are in the same boat.
As the weather improves, plants that have been dormant all winter begin to resume growth. In a perfect world, once the warm weather of spring arrives the plants would be past all chances of a refreeze. Unfortunately in these parts, we can be subject to late frosts that can harm trees, shrubs and tender plants like tomatoes.
Arkansas' springs are characterized by extreme shifts in the weather. We normally think of tornadoes and that sort of thing, but really the temperature variation is just as wild.
As a plant leaves dormancy, the physiological mechanisms that protect them from cold are turned off. When we are treated to a late frost, tender parts of the plants like the flower and leaves will be easily frozen. And that means no fruit or flowers for the upcoming year.
There are a number of steps gardeners can do to protect themselves. The first, and most effective, is to delay planting tender annuals until after our typically late frost date. In Fort Smith, the average last frost date is March 26; however, if you look at the chart, there is a lot of variation in when that date happens in the real world. I suggest using April 1 as the earliest time to plant. Even then there is still a 1-in-3 chance of a frost after that date.
For perennial plants like trees and shrubs, planting date isn't much of an option so it is important to select plant material that is well-adapted to our climate. For example, almonds are perfectly hardy here, but they usually freeze out because they wake up too early for their own good. The extension office has lists of good plants for this area – and they're free. Take one with you to the nursery!
Often the rules for recommended plants are broken (I'm guilty!). In this case, you have to provide some sort of protection.
There are two types: active and passive. An active measure you can do would be to cover sensitive plants with a box or, even better, an inverted trash can.
Many gardeners rely on floating row covers for frost protection. These are not hard to find and work very well. There are many other active techniques, but they require technical expertise and are not appropriate at homes.
Passive methods are much easier. Passive protection involves locating your plants in a place less likely to be exposed to cold. In general, high places are better than low ones since cold air sinks. Near bodies of water or structures may improve your chances.
When passive control works, it's amazing, but it isn't very reliable. I would plan to do both, if needed.
For example, budded out hydrangeas against your brick home are often fine on a clear-night frost, but if conditions change, you may lose the season's flowers. Covering them is a cheap insurance in my opinion.
Finally, remember that frozen plants are brittle. Try to avoid handling them any more than you need to or you might snap off a branch.
And you know that would have been the prettiest one ever.
Dustin Blakey is the Sebastion County extension agent for the University of Arkansas-Division of Agriculture Cooperative Extension Service office in Fort Smith. 479-484-7737, firstname.lastname@example.org