Winter Garden Care
With winter on its way, don’t leave your plants unprotected. We’ve compiled these tips to help you keep your garden healthy and prepare it for winter.
Perennials, with some exceptions (e.g. Heuchera, lavender, Carex, etc.), can be pruned back to their base once they have gone dormant. Dormant, for perennials, means that their foliage has died and appears brown. Waiting for this dormancy helps ensure that the plant will not put out sensitive new growth in response to being pruned. Tender perennials (i.e. those that are more susceptible to winter damage) should be layered with mulch to provide insulation after being cut back. As this extra mulch must be removed the following spring, you may find it useful to mark each plant’s location. Roses can be cut back to 24” and covered with a rose cone once they have lost their leaves (not necessary for shrub roses). Further pruning can be done in the spring when they are not at risk for winter damage. Climbing roses, once dormant, can be covered with burlap. As care for tree roses can be more complex, it is best to call or come in if you need information. Ornamental grasses can also be cut back at this point, with 4-6” of growth left. If you want to enjoy them as winter interest, you can wait until early spring to cut them back before new growth emerges.
Snow cover can be beneficial as it insulates plants, thereby protecting them from temperature fluctuations during the winter. Some plants, however, can be damaged by the weight of the snow and require extra care to mitigate this. To help protect your plants from snow damage:
- Keep plants properly pruned all season to keep the structure strong (call or come in for more information on proper pruning). Remove broken or damaged limbs before winter.
- If plants are small enough, place a structure over the top of your plant to prevent snow from building up on top. You can use teepees, rose cones, and shrub protectors.
- Plants like arborvitae and upright juniper can be bundled to prevent their branches from being broken by heavy snow loads. To do this, lift branches up at the base and tie string in a loop, tight enough to hold limbs in place. Work your way to the top of the tree with the string in tight enough spirals that it contains the branches.
- If the plant is particularly prone to breaking, it is best to remove the snow before it accumulates to damaging levels (e.g. Japanese maples).
Sun Scald and Frost Cracks
The southwest side of tree trunks are warmed by the sun the most, then when temperatures drop drastically overnight the inner bark can be damaged. This is common with thin-barked trees (young trees and maples, lindens, cherries, etc.)
- Prevention: wrap the trunk with tree wrap, burlap, cardboard, or fabric. Remember to remove wrapping once temperatures remain above 40°F.
Evergreens’ foliage is present during the winter, where it is not for deciduous trees, causing them to lose moisture. When the ground freezes, the roots cannot bring water up from the ground to replace the moisture they lose. What you can do to help prepare your plants:
- Fall watering is important, even when the temperatures are cooling down. Giving your evergreens enough water before the ground freezes is the easiest way to boost your plant’s store of water.
- Wrapping your evergreens in burlap creates a barrier between the foliage and the wind, thereby decreasing moisture loss. To wrap your trees, bundle with twine, then wrap in one layer of burlap, covering plant from base to tip. It is important here to note that overwrapping can be just as damaging as not wrapping at all. Remember: do not wrap before temperatures are consistently less than 40°F and remember to remove wrapping in the spring when temperatures exceed 40°F.
- Building a windscreen is a good method for hedges and plants that have been grown very close together. To do so, place stakes every 3-4 ft and attach burlap to stakes so that it shields most of the plant.
- Anti-transpirants are a spray-on product that reduces the amount of water lost through the plant’s leaves.
During the winter, many animals like rabbits and deer will turn to landscapes for food. To deter them, it is best to take preventative measures. This can train them not to use your yard as a food source. There are two options to do this: physical barriers or chemical barriers.
- Physical: Cages (e.g. hardware cloth), tree guards, and burlap.
- Chemical: Spray-on repellents that work on either the animal’s sense of taste or smell. Repellents must be reapplied year-round as per the manufacturer’s instructions to maintain effectiveness.
During prolonged periods of warm weather (above 40°F) be sure to remove plant coverings to prevent damage from overheating. If temperatures drop again, you will need to protect plant again to reduce freeze damage.
Sometimes, even with precautions, plants will still sustain winter damage, so having a healthy plant going into winter will help it to heal faster.
If you would like a copy of the above tips then click here for a handy PDF copy.