Garden Pros Say These 7 Jobs Will Protect Your Plants from Winter Damage – But They Need to Be Done in December
Experts reveal the key overwintering jobs to do in December to protect your yard from the worst of winter
December is a demanding month for plants. It is vital to get all your overwintering plans in place so that your delicate plants are protected from the winter elements. If you have fallen behind or procrastinated, there is still time to get key overwintering jobs done in December.
The important areas of overwintering a garden include protecting plants in the ground or pots, feeding the soil, keeping greenhouses insulated, and ensuring garden wildlife have all they need to survive. Get it right, and the contents of your garden will be shielded against snow, frosts, freezing rain, and strong winds.
7 Key Overwintering Jobs to Do in December
You may have prepared well and have ticked these off earlier in late fall or early winter. If so, congratulations. However, not all gardeners are so proactive and moving pots or protecting plants from frost may still be ongoing. If you live in US hardiness zones with milder winters, you may still have time before the worst of the winter weather hits.
For each of the key overwintering jobs to do in December, experts reveal their tips and insights to help you get the task done successfully. What will be essential is good quality gardening gloves to keep your hands warm and dry in winter. For example, a pair of these fully waterproof and thermal-lined gardening gloves from Amazon may be invaluable.
1. Mulch the Soil
December is the perfect time to focus on your soil's health. Mulching is the best approach for this, as it both nurtures the soil and protects overwintering plants in your borders and flower beds.
‘I put a lot of mulch around plants and trees in December,’ claims Loren Taylor, a seasoned landscaper, gardener and owner of Soothing Company. ‘Mulch is like a blanket for the ground. It keeps the soil very warm, protecting it from the cold and keeping the water there warm.’
Firstly, let's examine the ways that mulching benefits plants over winter. It insulates the roots, conserves moisture in the soil, smothers winter weeds, and protects against frost heave. It also offers longer-term benefits, too. When you use organic types of mulch, like compost, well-rotted manure, leaf mold, or bark chippings, these also break down to improve the structure and boost soil nutrients.
If you haven’t yet mulched flower beds or your vegetable garden, aim to do so before the first hard frost. Apply a layer 3-4 inches thick, but avoid piling the mulch against the stems or trunks of shrubs and trees, as this is a common mulching mistake that causes rot.
Loren Taylor is a seasoned expert in landscaping and gardening, with a keen eye for exterior design. As the owner of Soothing Company, he has spent 17 years honing his craft, transforming outdoor spaces into serene, beautifully landscaped environments. With a deep knowledge of plant species, soil conditions, and sustainable gardening practices, combined with a passion for creating harmonious outdoor designs, Loren has become a sought-after authority in the field.
2. Protect and Move Your Pots
If you haven’t finished protecting your container plants from winter weather, the clock is ticking. Whether this involves overwintering plants indoors or taking measures to protect pots and planters from frost, you need to do this before temperatures plummet.
Charlotte Weidner from Nature Hills Nursery highlights how plants growing in containers are ‘far more exposed to cold’ as their roots are not as insulated as those in the ground. So, you want to take action to help these plants survive cold winters.
‘In December, I recommend gardeners focus on gradually acclimating container plants before moving them indoors,’ she says. ‘This includes checking for pests, trimming damaged growth, and slowly adjusting plants to lower light levels.
‘Once inside, containers should be placed in bright, cool spaces and watered sparingly to avoid stress.’
If you aren’t fortunate enough to have lots of space to bring pots indoors, there are options. You can move pots together for winter so they can share warmth, such as clustering them together in a protected space.
Or you can wrap pots in frost cloth, hessian, or protective winter covers to insulate them from the frosts. A roll of burlap from Walmart makes an excellent material to cover pots for winter.
3. Wrap Tender Plants
Not all plants can be brought indoors for winter. There may be a need to wrap tender plants so they can survive the colder months outside in the garden. In particularly cold or exposed areas, it may not just be tender plants that need wrapping; even borderline-hardy plants will need a bit of TLC to ensure they overwinter successfully.
It is ideal to wrap plants early to overwinter tender plants, normally in October or November. However, if you haven’t completed it yet, there may still be time in milder winters if the temperatures haven’t dropped to dangerously low levels yet. So get the overwintering task done ASAP if you haven’t yet. As Loren Taylor advises: ‘The first thing I always do in December is wrap all the plants so they are not fully exposed to the cold.’
The likes of bananas, tree ferns, olives, citrus, cordyline, hibiscus, and passion vines are all tender plants to wrap up ahead of winter. Packing straw around plants and then covering them with an insulating wrap of horticultural fleece (such as this frost cloth at Amazon) or hessian can keep their delicate parts shielded from snow, frost, and freezing winds.
4. Protect Plants From Wind
Strong seasonal winds are often an underestimated threat to backyard trees and shrubs over winter, potentially causing as much damage as the cold. Putting necessary measures in place ahead of the worst of the winter weather can prevent many issues, including wind rock.
Wind rock is most prevalent in the fall and winter, when strong gales can batter trees and woody shrubs. The back-and-forth rocking from the winds can damage roots and even completely dislodge the plant, with recently-planted trees and shrubs most susceptible to it.
Patrick Martin, gardening and horticulture expert and the founder of Frantoio Grove, recommends homeowners in exposed sites put simple measures in place for winter to protect tall evergreens and shrubs from wind damage.
‘Tie in tall evergreens and shrubs to a solid stake and install windbreak mesh on the windward side in exposed gardens to cut gusts without creating turbulence,’ he says. ‘It prevents wind‑rock that loosens roots and opens the crown to rot.’
A simple temporary wind barrier can be made by stretching burlap or shade cloth between stakes installed around plants. Or you can add fencing screens (such as this natural willow fence roll at Amazon) to diffuse the wind; just make sure whatever you use as a windbreak is permeable.
To protect taller flowering shrubs from wind rock, it is recommended to gently prune roses, dogwoods, hydrangea, lavatera and other tall shrubs ahead of winter. Reducing their height by between a third and a half ahead of winter can keep them safe in exposed gardens.
Patrick Martin is a gardening and horticulture expert and the founder of Frantoio Grove, an award-winning olive farm and mill in California. With over 15 years of hands-on experience, Patrick combines his love of gardening and plant care with expertise in olive tree farming, helping others grow healthy, productive gardens.
5. Protect Evergreens From Winter Burn
Evergreen trees and shrubs can suffer from winter burn from drying winds and frozen soil. This seasonal issue stresses plants and causes foliage to turn brown, red, or yellow at the tips, and the needles turn dry, brittle, and drop from the tree.
Charlotte Weidner highlights broadleaf and needle evergreens, such as boxwood, holly, and juniper, as ‘especially vulnerable’ to winter burn. She offers the following advice for you to implement on your susceptible evergreens in December to prepare and protect them from freezing temperatures and dry winds.
‘Before the ground freezes solid, gardeners should deeply water evergreens and apply a thick layer of mulch around the root zone to help stabilize soil moisture,’ recommends Charlotte. ‘In exposed locations, installing breathable burlap wind barriers reduces moisture loss through foliage and prevents browning through winter.’
You can also use anti-desiccant spray on evergreen shrubs to protect against winter burn. Such a product creates a clear, breathable film on the leaves to lock in moisture and reduce the water loss over winter.
An example of such a product is this winter plant protection spray at Amazon that can be used on arborvitae, cypress, rhododendrons, holly, boxwood, spruce, pine, and more.
6. Keep the Greenhouse Warm
A greenhouse can be a valuable space for winter, as it becomes an ideal place for overwintering delicate plants. If you are fortunate enough to have a heated greenhouse, you can set a thermostat and relax, safe in the knowledge that your plants are cozy.
However, for many gardeners who wish to use a greenhouse in winter to overwinter plants, it is not always so simple. Even in a greenhouse, it gets very cold during the winter, so it is important to insulate or heat your greenhouse to protect against dropping temperatures.
A simple way to do this is to use bubble wrap as greenhouse insulation, which is something that Angus Mackintosh, Director of Designer Garden Rooms, recommends doing this month if you haven’t yet.
He advises greenhouse owners to ‘line first, then seal, then ventilate’, saying: ‘Fit horticultural bubble wrap neatly to the inside with proper clips, and seal draughts around doors and frames while leaving one vent operable for brief midday airing.’
‘Air for 15–30 minutes at midday on bright days to purge humidity without losing all the stored heat,’ adds Angus.
Insulating is an effective and budget-friendly way to winterize a greenhouse, and you can get rolls of bubble wrap at Walmart to fit inside your greenhouse. Other options include adding black water barrels, which act as thermal mass and soak up warmth during the day to release at night, or using electric fan heaters.
Angus Mackintosh is a garden room builder and landscape gardening specialist with extensive hands-on experience designing, constructing and managing outdoor spaces year-round.
7. Support Wildlife
Winter can be a difficult time for birds and other beneficial wildlife due to the scarcity of food sources. Gardeners are advised to help out during December by providing food, water, and shelter for visitors to your wildlife garden.
‘December is a critical month for feeding birds and wildlife,’ says Charlotte Weidner. ‘I provide high-energy foods and fresh water while making sure bird feeders are cleaned regularly. Dirty feeders can spread disease, so weekly cleaning keeps birds healthy and active in the garden all winter.’
You can clean a bird feeder with a very mild bleach solution or with warm soapy water, while Loren Taylor claims: ‘I clean feeders once a week with vinegar water to keep them healthy.’
Bird feeders for fall and winter can be filled with calorie-rich seeds or mixes, such as this bird banquet bird seed at Amazon. You can even put bits of fruit or cooked rice in bird feeders for an occasional high-energy treat.
On top of key overwintering jobs to do in December, there may be some pruning that needs doing around your yard this month. It will depend on the weather, as you don’t want to prune on frosty days, but if the ideal opportunity arises then check our guide to plants to prune in December to see what may need some attention. As not all trees and shrubs want pruning in winter, also see our piece on plants to never prune in December to avoid making any pruning mistakes this winter.
These plant covers can protect your plants from snow, frost, and freezing rain. They feature a drawstring, making it easier to cover and uncover plants.
This mulch is 100% organic and peat-free. It is made from upcycled plant matter or wood fines from the United States.
This set features a pair of loppers, pruning shears, and a pruning saw. It gives you all you need to complete lots of winter pruning of trees and shrubs.
