Time for an Inspection
Abrupt weather changes and extreme conditions, at any time of year, can do a number on plants. Gardening by the Yard host Paul James recommends spot-checking your landscape to see how things are faring.
Trees and Shrubs
Evergreen trees and shrubs often take the biggest hit during the winter months, especially when conditions are both cold and dry for extended periods. You’re likely to notice the colors fading in most evergreens, whether they’re green, blue or yellow evergreens. Some may even turn a slight bronze color, which is perfectly natural. But brown isn’t a color you want to see in evergreen plants. When you see brown, it almost always means the plant is a goner.
"Chances are the cause of the plant’s demise was a lack of water, assuming it was hardy to begin with," says Paul. "That’s why I’ve stressed for years the importance of watering evergreens during the winter months." After the first hard freeze of winter, it’s equally important to apply a fresh layer of mulch three to four inches deep around evergreens.
Deciduous trees and shrubs tend to fare better under extreme and changing conditions, but they too often need some attention. For example, they may need to be pruned to remove deadwood, open the interior to promote better air circulation and thereby minimize fungal diseases, or merely to reshape the plant. Just remember not to remove more than one-third of the growth. Any more than that may stress the plants beyond the point of recovery. Also remember as you prune to try to retain the natural shape of the plant. In other words, don’t just lop off the top growth to create a tabletop or lollipop shape.
You should also inspect the swelling or emerging buds on your plants, whether flower or leaf buds or both, says Paul. Unseasonably warm temperatures followed by hard freezes may damage those buds, causing them to shrivel up or fall off. Unfortunately there’s nothing you can do to reverse the damage, but at least you’ll know why a particular plant failed to bloom later in the season. And thankfully, in the case of leaf buds, many plants will produce secondary buds to take the place of the damaged primary buds.
Deciduous trees and shrubs may need a shot of horticultural oil while still dormant to smother scale, mites and other insects that might have overwintered on the plants.
Don’t be alarmed if some of your trees and shrubs still have brown leaves clinging to the branches this time of year. A number of deciduous plants – pin oaks, Japanese maples and hydrangeas among them – often retain their leaves throughout the winter months, even into early spring. So while they may appear to be in trouble, chances are they’re just fine.
Certain perennials might need to be tended to this time of year as well. In mass plantings of mondo grass and the similar-looking liriope, many people use a string trimmer or mower in late winter to cut back the bulk of the foliage. That’s fine, because both plants are extremely rugged; however, as with ferns, try not to damage the crowns.
When cutting large clumps of ornamental grasses, Paul suggests wearing a long-sleeved shirt and gloves. Why? "Grass blades are sharp, and without protection you’ll wind up with what appear to be dozens of painful paper cuts," he says.