- When the heat is on, humidity inside our houses tends to be relatively low. Group plants together to raise the humidity around them. Plants in smaller pots may be placed in trays of pebbles with water added. Avoid locations where warm air from vents will blow directly on them or locations where cold drafts will blow on plants.
- Apply mulch over the crowns and roots of some of the less hardy perennials during the coldest part of the winter. Pine straw, clean hay, pine bark mulch, and dry leaves all work well for this purpose.
- Cool to cold temperatures, typical rainy weather, and the dormant conditions of many perennials generally make watering unnecessary. If the weather turns mild and/or dry, water beds as needed.
- Few herbaceous perennials are in active growth during the winter and January is not the best time to fertilize them. Dormant perennials do not need fertilizer.
- Insect and disease problems are at a minimum this time of year. Cool season weeds will be in active growth any time mild weather occurs.
- Keep beds mulched 3 to 4 inches deep and promptly pull up any weeds as they appear. If the temperatures rise above 65 degrees, tough weeds, like wood sorrel, may be treated with a weed-control aid. Since you should be careful not to get any on the foliage of plants, it is easier to use when the perennials are mostly dormant and there is little or no foliage present.
- Cut back and remove old, dead upper portions of dormant perennials. This will keep
the garden looking more attractive. Chop up the material and put in your compost
pile. Some perennials don’t go dormant until the first freezes hit.
Shrubs – Planting and Transplanting
- This is an excellent month for planting and transplanting shrubs.
- Generally, no need to water established shrubs unless newly planted. They should be watered thoroughly but may not need to be watered thereafter if rainfall is regular.
- If a hard freeze is expected and the soil is dry, water thoroughly to help protect from freeze damage.
- This is an excellent time to apply horticultural oil sprays to shrubs that are prone to scale. These include camellias, hollies, magnolias, euonymus, privets and cleyera.
- Spray gardenias with horticultural oil for whiteflies.
- Do not use horticultural oils if the nighttime low is predicted to be below 40 degrees Fahrenheit.