When Spring Comes Too Early
Don’t wish away winter too soon. Cold weather is great for plants. Here’s how to handle mid-winter warm spells in your garden.
Winter weary northerners who’ve had enough bone-chilling weather are thrilled when the mercury hits 50 degrees or more in late February or early March. It’s easy to be tricked into thinking that spring has officially arrived, even if you live someplace where snow is common in March. Some plants can be easily fooled as well. Swelling buds on cherry trees and magnolias, bulbs popping up here and there, and perennials emerging from a long winter’s nap are all ready for spring to begin.
What’s a gardener to do? In some cases, the answer is to hope that snow (or at least freezing weather) returns again soon to send those eager plants back to sleep for a little while longer. A return to cold weather before buds break on fruit trees is essential to preserving a robust crop. But cold hardy bulbs that have just begun to show their leaves and still have their flower buds buried underground will take freezing temperatures in stride and continue to grow again once winter has truly passed.
You may be tempted to head out on a warm weekend day in winter to start your spring cleanup, but it’s best to resist this urge. Last year’s foliage and leaves are protecting the roots of your plants and helping to insulate them from the wild temperature swings that can occur this time of year. The soil tends to be wet from melting snow and winter rain. Walking on it now will compact it, compressing the tiny air spaces that roots need to grow. Stick to pathways when walking around your garden on warm winter days.
The shredded leaves or bark mulch you dutifully spread in fall will help to keep the ground temperatures steady and your plants dormant during short warm spells in late winter. If you see some of your perennials starting to come up too early, now is a good time to spread a thin layer of additional shredded leaves on them to keep them from bolting up on the next sunny day. If some have worked their way out of the ground due to freezing, then thawing, soil, gently press them back down into the soil so their roots are covered.
Resist the urge to prune trees and shrubs now too. Doing so could stimulate new growth which will surely be damaged when winter snaps back into place. It’s best to prune once, after all likelihood of damaging cold has passed. Read more about when to prune here.
If your trees and shrubs do start to leaf out during a winter warm spell and are then killed off by late winter freezes, most will have a secondary set (think backup plan) of leaves that will sprout again in spring. However, this is very stressful to the plant and if the summer is harsh as well, even mature trees and shrubs will need extra moisture to keep them healthy.
Hydrangeas, Japanese maples, and other small trees and shrubs that have leafed out prematurely can be covered with old blankets or the like on nights that fall below about 36 degrees to help protect their buds. Be sure to weight the corners of the blanket down so it doesn’t blow off overnight. Even with this protection, there is little that can be done on very cold-sensitive plants like Hydrangea macrophylla if temperatures fall well-below freezing once their buds have already begun to open.
So don’t wish winter away too soon. Cold weather is good for gardens, and spring will come when it is good and ready!