December Gardening To-Do List

When you’re gathering merry bloomers for your home, request a paper sleeve or sack to protect plants from cold outdoor air. If you’re running holiday errands, don’t let plants sit in a cold car. Try to arrange plant purchases so they’re the last stop before you head home.

Once you get poinsettias like this Sonora White Glitter type home, display them away from cold drafts (not by the front door) or heating vents. Water to keep the soil consistently moist. Poke holes in any foil surrounding the pot, and set the pot into a saucer. If you don’t do this, your plant is likely to be sitting in water.

As outdoor decor shifts from Thanksgiving harvest to festive greenery, keep an eye out for discarded pumpkins. If you really want the good gourds, ask neighbors ahead of time if you can pick them up. Who doesn’t love door-to-door yard waste service? Chop pumpkins into pieces before burying them in your compost or vegetable garden. Don’t bury seeds unless you want vines next year (although you can plan to hand-pull them). If you’re a bird-feeding fan, dry seeds, chop them into small bits and add them to birdfeeders.

When shopping for cut Christmas trees, check freshness by grabbing a branch and running it through your hand. Fresh needles should spring back and stay attached to the branch. If they don’t, look for a better tree. You can also lift the tree a few inches and drop it against the ground. See a shower of needles? Keep looking. Some evergreen trees hold their needles better than others, including fir (balsam, Fraser, Douglas and white), spruce (white) and pine (red, Scotch and white). One last clue to check: A fresh tree has a moist trunk base and might even have sticky sap.

If the ground isn’t frozen yet, take time to water trees and shrubs that were planted in the last 12 months, especially if your region is experiencing drought. Use a garden hose, or if the hoses are unhooked due to freezing nights, carry water in a bucket or watering can. New landscape plants need adequate irrigation to survive their first winter. Other plants that benefit from water include shallow-rooted blueberry shrubs (shown), European white and paper birches, alders, lindens, hornbeams and maples. Also, water evergreens like boxwood, rhododendron, azalea or Oregon grape-holly to help prevent winter burn. Water only when air and soil temperatures are over 40°F and there’s no snow on the ground.

In mild winter regions, fall-blooming Sasanqua camellias are still looking great. If a local public garden has a camellia garden, it’s worth a visit. Use it to plan which one you want to add to your yard next year. This variety is ‘Yuletide,’ which unfurls rosy red flowers from fall through the Christmas holidays. New introductions include shorter, wider varieties that make great ground covers. For best success with Sasanqua camellias, aim for part shade with well-drained soil.

Build barriers around plants that typically get flattened by ice and snow — whether it’s falling from the sky or sliding off nearby roofs. Some trees, like this ‘Hanami Nishiki’ Japanese maple (Acer palmatum), are easily damaged by heavy snow. A simple bamboo tepee should protect trees sufficiently in Zones 6 and warmer. For marginally hardy evergreen plants, especially those in windy locations, erect winter windbreaks using burlap and metal fence posts.

Add a merry touch to flowerpots brimming with cool-season annuals. All it takes is an evergreen branch, a few redtwig dogwood stems or berried holly branches to bring on the holiday cheer. Plants like Cool Wave Spreading Pansy (shown), viola, sweet alyssum and flowering kale and cabbage create a pretty groundcover that complements holiday decor. When planting containers in autumn, think ahead to Christmas, and choose annuals that transition easily through the holiday season.

Wait to prune dormant ornamental grasses until spring. The stems help protect the crown or growing point of the grass from repeated freezing and thawing, which can cause damage. Often grasses collapse or “lodge” under the weight of snow and ice over winter, which further helps insulate the crown from cold and ice. Some grasses, like this ‘Northwind’ switch grass (Panicum virgatum), bounce back after lodging, even when coated with snow and ice. Once the cold stuff melts, stems rebound to stand upright.

Keep bird feeders well-stocked through winter. Black oil sunflower seed attracts the widest variety of birds — but it’s also a squirrel favorite. Safflower seed is a good choice when you want to offer something that both squirrels and house sparrows dislike. Try mixing both types of seed in a feeder along with a few peanuts for a beak-pleasing buffet that beckons black-capped chickadees, tufted titmice, cardinals and woodpeckers. Hang suet feeders for woodpeckers and thistle seed socks for finches, like this common redpoll.

Keep an eye on houseplants through winter, especially ones in sunny south- or west-facing windows. Non-humid winter air causes houseplants to dry out quickly. While it may not be too much of an issue for a succulent like this ‘Bad Hair Day’ mangave, it can reduce growth for other less drought-tolerant plants. At the very least, check plants weekly to assess soil moisture. Sticking a finger onto — or even into — soil is an easy way to determine if plants need a drink. With small plants, lifting the pot is another good way to figure out how moist the soil is. Dry soil is light; wet soil is heavier. Soil color also changes as moisture evaporates. Wet soil is dark; dry soil is lighter in color.

Keep adding kitchen waste to your compost pile through winter. In the coldest zones where compost piles freeze beneath heaps of snow, stash kitchen waste in a trash can with a tightly fitting lid through winter. Store the trash can outside in an easily accessible spot. Use a liner or not — it’s up to you. In spring, as soon as the first few inches of compost thaw, remove the top layer, add your winter waste, then cover. Burying kitchen waste helps reduce odors and prevent critter foraging. If winter is your rainy season, cover the top of your compost pile to help keep it from becoming waterlogged. A too-wet compost pile lacks oxygen and can become stinky.

December is typically a low-pruning month in most regions. Many tree trimmers tackle oaks in Zones 6 and cooler in December, because oak wilt fungal disease isn’t active then. In the Desert Southwest, it’s a good time to prune deciduous trees because you can see the tree’s shape well. In most regions, it’s better to wait until January or later in winter to prune, when plants are fully, deeply dormant. The exception is anything that’s damaged by winter storms. Clean up broken branches when they happen to prevent further damage to trees.

Make some holiday magic with amaryllis bulbs. Watching these stately bloomers grow and unfurl is sure to inspire awe. Choose waxed bulbs for a go-anywhere show, like popping them into a pretty pottery vase. Or follow a more traditional pot-planted path. Either way, after flowers fade, snip blossom stems at the base. Continue to grow the leaves through winter and plan to set plants outside for the summer if you want to savor the flower show again next year.

When foraging greenery for decking the halls, remember that some holiday favorites are poisonous to pets and people. The list of problem plants includes holly (including winterberry holly, shown), Jerusalem cherry, boxwood and mistletoe. Display these jolly stems well beyond the reach of young children and curious pets.

In Florida, avoid gathering the eye-catching red-fruited stems of Brazilian pepper. This plant is related to poison ivy and sumac, and many people have allergic reactions to it, from dermatitis to breathing problems.

In regions with mild, rainy winters, if frost threatens, move outdoor potted tropical plants to a protected spot on a porch, lanai or Arizona room. But for tropical succulents that are sensitive to overwatering, place plants in a covered location throughout winter to help protect them from seasonal rains. This list includes agave, Aeonium, desert rose, blue chalksticks or mangaves like this ‘Tooth Fairy’ variety.

Give your vegetable garden a thorough double-check for any remaining root crops you might have missed in your fall clean-up. Stray onions, garlic and potatoes are easy to miss in a crowded summer garden, but in fall’s cooler temperatures, growth takes off, making plants a snap to spot. Allow an onion like this to remain in place over winter, and you might be harboring onion maggots, which will infect next year’s onion and garlic crops.

Before deer start browsing on woody ornamentals, grab your favorite repellent and treat plants early in the season. Plantskydd works well to provide a winter-long deterrent for deer. Follow directions carefully regarding temperatures for application and drying time. It’s also a good idea to toss bird netting over plants they tend to devour, including things like hydrangea, blueberry or yew.

Gardeners love to push the envelope and grow plants on the edge of their hardiness zones. If that’s you, consider giving tender plants some extra winter protection by providing a layer of insulation. You can wrap shrubs with burlap, insulate them with a Styrofoam cover or use a pop-up type plant protector. With any of these methods, enhance the insulating effect by stuffing the cover with chopped autumn leaves.

Dress up container gardens with boughs of fresh evergreens for a colorful winter display that can stay in place through the holidays and beyond. Greens like spruce, fir, mountain hemlock and Virginia pine retain color and needles to provide a long winter display. Treating cut greenery with an anti-transpirant helps stems retain moisture. To add a strong vertical element, use individual or bundled branches of redtwig dogwood or white paper birch, or bury the bases of bunched ornamental grass stems.

Whip up a cozy cup of cocoa, and dig out your garden journal while the garden season is still fresh in your mind. Read through your entries, adding notes as needed about pest issues, drought conditions, fruit yields or whatever is important to you. Take time to begin creating garden goals for next year, including things like tomato varieties you want to try, seeds you need to order, pests you need to watch for and any other tidbits that pop into your mind. Do this exercise a few times this month for a break from the holiday rush.

For beautiful, easy color, add some paperwhite bulbs to a container filled with gravel or glass flower-arranging pebbles. Choose a tall container so you'll have built-in support for this bulb’s floppy stems. Cool air temperatures slow plant development, while warm air speeds things along. Paperwhite blossoms release a rich fragrance, which can be too much for family members with allergies.

If your hose split this summer, purchase a repair kit and tackle the job now so it will be ready to go next spring. For hoses on hose reels that have developed a leak, bring them into a warm basement or garage area with a drain and make the necessary repairs. You may need to remove the hose from the reel to replace the washers inside the hose-reel connection. If you store your hoses in an unheated shed, bring them into a warm spot for a few hours to make them flexible and easier to handle.

In areas where ponds freeze over in winter, use a pond heater to maintain an opening in the ice. Having an open spot protects fish by allowing harmful gases in the water to escape while letting oxygen in. In the coldest areas, many pond owners have a backup heater, along with a plan for storm-related power outages. If a solid sheet of ice does form on your pond, create a hole by pouring hot water onto the ice. Do not pound on the ice. The sound waves stress fish, which leads to a compromised immune system and possibly death.

For cool-weather greens, such as lettuces, mustard and turnip greens, chard and Asian greens, set up a framework around your growing area that makes it easy to slip a frost blanket into place. Cover crops when air temperature drops below the mid-20s, anchoring it tightly to the ground. The covers work by trapping radiant heat in the soil and holding it near plants. Gaps that let in cold air reduce the blanket’s effectiveness. Vent the blanket on sunny days to avoid killing your plants via steam.

Check the water in your Christmas tree stand twice daily — morning and evening work well. Always add water to keep the level well above the cut end. If the water drops below the cut, the trunk may self-seal. The only way to fix that is to re-cut it, which is no small task on a decorated tree. Typically a fresh tree absorbs about 1 gallon of water in the first day after cutting off the end. After that, expect it to drink roughly 1 quart of water per inch of trunk diameter daily.

Look around your landscape and make sure that bare soil is covered to prevent erosion over winter. This is especially important if you have worked hard to build healthy, rich soil. Use chopped leaves, straw or some other organic material to cover soil, especially in areas where you typically grow annuals or vegetables. How thick should the layer be? As thick as you want. It will compress through winter. In spring, plant directly through the mulch.

Give local birds a place to sip and bathe all winter long by using a birdbath heater or heated birdbath. Keep the water topped off and fresh, cleaning the bath as needed. If your bath is deep, add a few rocks near the edge to provide perches for smaller birds. Most heated birdbaths have an internal thermostat that cycles on and off to keep water from freezing, so energy use is minimal. Snow and ice tend to build up along the bath's edges. Knock those off occasionally to give birds a place to perch.

When storms encase trees and shrubs in ice, do not go out and shake branches. It seems logical, but you actually risk damaging plants. Wait for the ice to melt, and check on plants again. Branches should return to normal position once the ice is gone. If any branches break under the icy weight, prune only what’s necessary to prevent further damage — and wait to do it when conditions are safe. Handling pruning tools with ice underfoot is never a good idea.

When it’s time to clear walks and driveways, move snow carefully, thinking about where you can place it so it won’t crush woody plants, like roses and shrubs. If you live in a snow-prone region, you might want to fill areas where you or the local snowplow tend to pile snow with perennials and shrubs you cut back in spring, like Russian sage, bee balm, black-eyed Susan, caryopteris or butterfly bush.

Moth or Phalaenopsis orchids typically bloom during winter’s cooler days. To prolong the flower show, water plants properly, not allowing them to become overly dry, which can cause buds to drop. Distilled water also helps maintain healthy orchids, along with proper nutrition, like RePotMe’s liquid MSU Orchid fertilizer (13-3-15). Research to determine if you want to remove spent flower spikes — there’s a healthy debate on that topic.

As winter settles in with snow cover, rabbits begin wreaking havoc on plants they typically pass up, including perennials like coral bells and Lenten rose. They create the worst problems on shrubs, where they gnaw bark. Protect vulnerable shrubs with chicken wire. As the footprints in the snow reveal, a rabbit was surveying this pussywillow for a bark-shredding nibble. For shrubs that rabbits have bothered in the past, add chicken wire before snow arrives, but you can also jam it into snow banks if you notice a damaged shrub after the fact. Chicken wire won’t keep voles from accessing stems for winter snacks. Hardware cloth is the material of choice for that job.

If you still have bulbs lying around, as long as the ground isn’t frozen, you can tuck them into the soil. Compost any that are mushy, show signs of decay or are dried up. It’s also a great time to plant bareroot trees, especially in regions with mild winters. Bareroot trees are terrific bargains and usually take off quickly in winter growing conditions. In areas where the ground freezes in winter, place online orders now for bareroot trees that will ship for spring planting.

Freezing temperatures bring out the sweetness in many vegetable crops as plants convert starch to sugar as a form of botanical antifreeze. Sugar freezes at a lower temperature than starch, so the conversion process helps plants withstand frosty nights. Vegetables that defy frost via sugary chemistry include Brussels sprouts (shown) and kale, both of which can be harvested from beneath a snow cover. You may have to let your harvest thaw a bit indoors before proceeding with meal prep, but your tastebuds will be rewarded with a sweet bite.

Make sure your snowblower is good to go for winter use by starting it and letting it run a bit before you need it. If you have an electric start, keep the necessary extension cord handy and accessible. Once snow falls, before firing up your snowblower, spray silicone spray on the chute, auger and other parts that come in contact with the snow. The silicone helps prevent wet snow from sticking to the blower and keeps it moving through and away from the machine. Silicone spray is a gift when snow is heavy and wet.