Penn State Master Gardener and Member of Warren Garden Club
It seems that everywhere gardeners meet these days the topic of conversation is always, how is this unusual winter going to affect our gardens. First of all we must remember that though these above normal temperatures are out of the ordinary it is not the first warm winter we have had and it is not the last and I am paying no attention to the Mayan Calendar's prediction of Armageddon.
It is impossible to say for certain how this weather will affect our gardens but there are some things to keep in mind. All gardens are different. In my zone 4 garden the soil is frozen although I don't know how deeply and we have had snow cover through most of the winter. Zone 5 gardens may not have frozen soil and may have had very little snow cover.
All my flowers were well mulched last fall. Mulch regulates the soil temperature thereby keeping plants from breaking through the soil too early. But even with well mulched garden beds, a few of my plants have still broken through the soil. The tips of these spring bulbs may turn black but hardy bulbs should flower. The flowers may not be as large or prolific but you should get something. Doing research for this article one "expert" suggested carefully placing compost over the plants. I have not done this before and I cannot recommend it but I am going to give it a try in couple of places and see if it helps. If you are going to try this little experiment keep track of dates and results in your garden journal.
Many of our plants require a period of cold weather and it is possible they have not chilled sufficiently. Hostas need 40 days below 40 degrees to produce full sized leaves and shoots. Other plants like cherries, black currents and some apples also need deep cold for an extended period. While we may have had enough cold days they were in an irregular pattern. Will this make a difference, no one knows.
Another problem could occur with fruits that depend on pollinators. These plants might blossom too early before the pollinators come out for nectar. If the blossoms are not pollinated there will be no fruit.
A few of our plants that thrive in warmer climate zones should do better than ever. We all push the envelope with plants that are recommended for zone 6 that we plant in our zone 5 garden "just to see how they will do." These plants should be much happier in our garden this year. One thing to definitely put in your garden journal this year would be to keep track of the effect of the weather this winter on specific plants. Note which thrive and which do not live up to expectations. Be sure you are keeping track of the day to day weather during the winter months and the summer months.
Low or no snow cover can cause the soil to heave and thaw pushing plant roots and plant crowns upward out of the ground and thereby exposing roots and plant crowns to the drying wind. This desiccation will be damaging and can be fatal to our plants. Rather than trying to push the plant back into the ground, I would try to cover the roots with soil. Keep track of how you tried to remedy the situation and how the plant survives.
As far as precipitation this winter the plants don't care if it is in the form of rain or snow. This winter we have had lots of rain. Most of our soil is nicely saturated. At least we have that.
With a warmer than usual winter many plants will bud and flower earlier. The problem with this is that the flowers may be weaker and smaller than usual. Also frost could freeze early buds giving no flowers at all. Some common plants that may not flower are the rhododendrons and hydrangeas. If the fleshy buds on these plants freeze they will not flower. You can try and protect these plants by throwing a tarp over them if they bud too soon and a frost is expected.
Trees and shrubs may break dormancy too soon. If the sap is running and a deep freeze occurs the bark may crack and the tree may eventually die. At our house we are watching an old oak tree that has a large crack. Every year it is a little weaker.
We have no idea how the insect population or how plant diseases will survive. Will insects emerge to early and succumb to a frost?
A good hard winter usually keeps everything in balance. We still have March. The long range forecast seems to be a toss up as to whether it will be cold and snowy or continued warm and rainy.
How will the winter affect our gardens? Most will probably survive although it may not be our best season ever. Get those garden journals out and keep good records. Don't be fooled into expecting an early spring, it will probably come along about the usual time. Stay out of your garden. At this time of year, the soil and plants are fragile. However a late afternoon walk around the garden is a treat on these warm days and you can always pick up sticks.