Annuals and Perennials
Wrap outdoor containers with an insulating material to keep your plants’ roots warm. Even cold hardy plants may not be able to withstand winter temperatures when planted in a container, as their roots are less insulated.
Apply cow manure and other organic soil conditioners to your garden beds.
Perennials such as iris and black-eyed Susan may be brown and dormant, but their seed pods provide food for the birds. Consider leaving them up for a while before cutting them down for spring.
Winter flowering plants usually need more water, while plants that are not blooming need less. Check the soil regularly and thoroughly water when the soil feels dry, until water drains from the drainage hole of the pot.
Plants that receive plenty of light in other seasons may need to be moved to a brighter location or have natural light supplemented by a light bulb for houseplants. If your plant looks leggy or spindly, this may be the reason.
Dry indoor air can be tough on houseplants. Increase humidity by grouping plants together on a humidity tray. You can make one by filling a saucer with pebbles and water. Simply place the plants on top of the pebbles, and as the water evaporates it will increase the humidity around your plants.
Reduce fertilization of plants that are not actively blooming during this time.
The cool temperatures of January induce flowering in many orchid species.
Check the leaves of your houseplants for insect problems like scale, mites, gnats and mealy bugs. If you detect a problem, bring a sample to our plant clinic for diagnosis and treatment solutions.
Look for roots protruding from the drainage holes or up over the top of your houseplant pots. If this is happening, repot your plant to a larger pot.
Visit or blog post on common winter houseplant issues for more detail about watering, repotting, light and pest issues.
Trees and Shrubs
Broadleaf evergreens, recently installed plants and trees and shrubs growing in containers are prone to damage from drying out (desiccation) in the winter. To prevent plant damage from desiccation, complete the following tasks on warmer days:
- Check on your plants when the temperatures rise above 40 degrees and thoroughly water them if they are dry.
- When the temperature is above 45 degrees, apply an anti-desiccant to azaleas, rhododendrons, hollies and other broad-leafed evergreens that are especially prone to drying out.
January and February are the best months for pruning many deciduous trees and shrubs and fruit trees. When removing branches, take care to avoid injuring the branch collar.
Extremely cold temperatures can injure or kill even cold hardy plants if they are growing in containers since their roots are not protected from the cold by the ground. To prevent cold damage in your container trees and shrubs, wrap your containers with an insulating material, such as bubble wrap or burlap, move them into a garage or against the house, or place unopened bags of mulch around them.
Check your water feature pumps regularly to make sure they are working properly. Larger pumps that move a lot of water will typically keep running throughout the winter without any problem. Smaller pumps, however, will most likely freeze and should be turned off for the winter.
Use a floating pond de-icer to help your fish survive the winter.
Natural food sources in our landscapes are scarce at this time of year, so feed the birds with suet cakes and birdseed to provide protein and fat. If squirrels are monopolizing your bird feeder, consider adding a baffle, using safflower seed or switching to a squirrel resistant feeder.
If you have a bird bath in your garden, be sure to use a de-icer to prevent the water from freezing.
Protect your landscape from hungry deer. Repellents produce strong scents and some are combined with a nasty taste to deter deer from browsing in your garden. Continue to apply them on a regular basis as feeding pressure often increases in the winter.
Turn over unused containers to prevent them from collecting water that could freeze and crack the container.
Use a good quality ice-melting product such as Mag (magnesium chloride) on sidewalks and driveways rather than, salt or rock salt, which can damage the concrete and shrubs.