January Gardening

January is not an especially good season for planting or disturbing the soil, especially in the Portland area where our soil is primarily clay. It’s likely that your soil is water-logged or frozen, and disturbing clay-based soil in these conditions often compacts the soil, making it harder for the plants in the long run. You probably won’t kill a hardy plant if you plant it now, but it is better to wait a while. 

Flowering primroses and pansies are excellent options for winter color. We carry pansies throughout winter and spring, and many more plants will be available soon enough. Hellebores have just started blooming and they’ll definitely add a bit of magic to your outdoor spaces. If you haven’t seen hellebores at their best, do so soon—you’ll be impressed! If you already have  hellebores in the ground, some of the leaves might be damaged by freezing weather. They aren’t helping the plant and may be hiding the beautiful flowers, so they should be removed.

If they’ve had two or three months of chilling, you can start forcing your bulbs inside now. Tulips, Narcissus, and hyacinths are all good plants for this. Plant them in fresh potting soil and grow them in bright windows, keeping the soil evenly moist. They’ll bloom soon after and you can enjoy a little bit of spring in the midst of winter. Once the bulbs are done blooming and spring arrives, plant the forced bulbs outside. They may naturalize and come back the following year!

Most plants are dormant now, but there are still several wonderful winter bloomers to enjoy in January. Witchhazel (Hamamelis spp.), some heathers (Erica spp.), winter jasmine (Jasminum nudiflorum), Camellia sasanqua, and Garrya elliptica all bloom this early. Winter daphne (Daphne odora) and wintersweet (Chimonanthus spp.) may be starting as well. It’s quite pleasant to have colorful shrubs in the middle of winter, but they all smell amazing too! Some of the best scents in the world can be found in a winter garden.

Other than protecting broadleaf evergreens and semi-hardy plants during hard freezes, little care needs to be given to permanent plantings in the ground.

Many ornamental deciduous trees prefer winter pruning, but it is still a bit early to prune most fruit trees. Most shrubs should be pruned after blooming, so we don’t usually recommend doing so in winter. There are exceptions, like dead branches needing removal. Most conifers do best with little or no pruning, but any moderate to major cuts needed should be done in late autumn to midwinter to minimize sap loss. Minor shearing of hedge or topiary plants can be done now, but they will look better if you wait until spring when they will flush back out quickly. If you are pruning branches off of early flowering plants such as cherry or forsythia, understand that you will have fewer blossoms on your plant in spring. The good news is , if you take some of the smaller cut branches inside and put them in a vase, the blooms will open with some enjoyable early color..

If you can find a dry day, dormant spraying can be done in January, though a lot of gardeners wait until February. Dormant spraying your deciduous, disease or pest prone shrubs and trees will help prevent infections later in the growing season. Dormant sprays—like copper sulfate, lime-sulfur, and horticultural paraffinic oils—will damage leaves, so it’s important to only use them when the plant is leafless. Fruit trees, roses, and lilacs all benefit from dormant spraying.

Snow and ice tend to arrive in January, and upright conifers such as arborvitae and cypress can lose branches in harsh weather. It is a good idea to wrap such plants with twine for a few weeks, binding the branches together to provide support. This can minimize any damage to the plants.

It’s still too early for starting veggie seeds in the garden, but our new stock of seeds will be arriving  and our selection is at its best. If you have kale or other winter greens growing outside or in a cold frame, they’ll need to be protected with a frost blanket during severe dips in temperature. If we are expecting a severe storm, consider harvesting the rest of your greens and eat fresh salads while you’re snowed in.

There is little to be done for lawns in the heart of winter. Wait for fairer weather for any seeding or renovation. Moss can be a problem throughout the winter, and applications of moss control products can help to slow the spread. Be sure that the product you select is labeled for lawns, as some moss control products can damage your grass and other plants. Also, heavy rains following application will simply wash the product away, so time your spraying appropriately.

Even though your indoor plants are heated and not fully dormant, their growth rate often slows in winter because of the lack of natural light. Grow lights can help, but most houseplants don’t require them. It’s also important to avoid fertilizing and to water moderately in winter, allowing plants to partly or even mostly dry out before watering. It is more common for people to overwater plants in winter than to let them get too dry. Repotting should be put off until spring, especially for dry-loving plants such as cacti or succulents.

Often, people acquire winter blooming plants over the holidays, and some of these can turn into permanent houseplants. Christmas cactus can live for many years and are quite easy to rebloom. Despite being a cactus, they cannot handle extended periods of dry soil and should be moderately watered like most houseplants. Poinsettias often fail after serving their decorative purpose, but if you have treated yours well it may be able to continue to thrive and rebloom next year. Both poinsettias and Christmas cacti require a long night cycle from autumn to early winter in order to rebloom, so be sure to plan accordingly. Note that indoor lighting in your living room or bedroom can disrupt this cycle. Paperwhites should generally be discarded after flowering.

Many species of birds overwinter in the Portland area, including some hummingbirds. Continuing to provide seed, suet, and nectar helps to keep populations healthy. When the temperature drops well below freezing, regularly placing containers of water outside provides drinking water for them.

Living (potted) Christmas trees should not be in the house longer than one week. In other words, by January, the tree really needs to be back outside. Learn more about living Christmas Trees.