December - Grower's Calendar

December - Gardening Outdoors and Indoors: How to Care for Garden Beds and Potted Plants in January. Tips, Advice and Guides from Sowing to Harvest...

Winter Garden Care in December and January

December marks the quietest period in the gardening calendar, but that doesn't mean your plants don't need attention. Whether you're tending to hardy perennials in your garden beds or nurturing houseplants indoors, proper winter care ensures healthy growth come spring. Here's your comprehensive guide to plant care during the coldest months of the year.

Outdoor Garden Care in December

Protecting Garden Beds from Frost

Winter protection is essential for perennial plants and bulbs that remain in the ground. Apply a thick layer of mulch, straw, or fallen leaves around the base of plants to insulate roots from freezing temperatures. This protective layer helps maintain soil temperature and prevents frost heaving that can damage root systems.

Winter Pruning Tasks

December is an ideal time for pruning dormant trees and shrubs. With leaves fallen, you can clearly see the plant's structure and remove dead, diseased, or crossing branches. Avoid pruning spring-flowering shrubs, as you'll remove next season's flower buds. Focus on:

Fruit trees (apples, pears, plums)
Ornamental trees and shrubs
Climbing roses (light pruning only)
Dead or damaged perennial stems

Planning Next Season's Garden

Use these quiet winter months to plan your spring garden layout. Review last season's successes and failures, order seed catalogs, and sketch out crop rotation plans for vegetable beds. Consider which new varieties you'd like to try and make notes about companion planting combinations.

Indoor Plant Care in Winter

Adjusting Watering Schedules

Most houseplants enter a semi-dormant state during winter, requiring significantly less water than in their active growing season. Overwatering is the most common winter mistake. Check soil moisture before watering - the top inch should be dry to the touch. Tropical plants may need occasional misting to combat dry indoor air from heating systems.

Light Requirements in Short Days

With shorter daylight hours, ensure your indoor plants receive maximum available natural light. Move them closer to windows (but away from cold drafts), clean dusty leaves to improve light absorption, and consider supplemental grow lights for light-hungry species like herbs, succulents, and flowering plants.

Temperature and Humidity Management

Keep plants away from heating vents and radiators that create hot, dry air. Most houseplants prefer temperatures between 15-24°C (60-75°F). Maintain adequate humidity by grouping plants together, using pebble trays filled with water, or running a humidifier in rooms with many tropical plants.

January Sowing and Propagation

Starting Seeds Indoors

Late December and January is the time to start slow-growing annuals and perennials indoors under grow lights. These plants need a long head start before outdoor planting. Consider sowing:

Geraniums (Pelargonium)
Begonias
Snapdragons
Pansies and violas
Certain herb varieties

Use sterile seed-starting mix, maintain consistent moisture, and provide bottom heat (20-22°C) for optimal germination. Once seedlings emerge, ensure they receive 14-16 hours of light daily to prevent legginess.

Winter Propagation Projects

Take advantage of indoor time to propagate houseplants from cuttings. Many popular houseplants root easily in water or moist propagation mix during winter months. Try propagating pothos, philodendron, spider plants, and succulent cuttings that have callused over.

Winter Harvesting and Storage

Cold-Hardy Vegetable Harvesting

Some vegetables actually improve in flavor after frost exposure. Hardy winter vegetables like kale, Brussels sprouts, parsnips, and leeks can be harvested throughout December and January. Many root vegetables can remain in the ground under mulch and be harvested as needed.

Storing Your Harvest

Properly stored root vegetables and winter squash can last for months. Keep them in cool (0-4°C), dark, humid conditions in a root cellar, unheated garage, or basement. Check stored produce regularly and remove any showing signs of decay to prevent spread.

Greenhouse and Cold Frame Management

Maintaining Optimal Conditions

If you have a greenhouse or cold frame, monitor temperature fluctuations carefully. Even on sunny winter days, temperatures can spike unexpectedly. Provide ventilation on mild days and ensure heating systems function properly during cold snaps. Continue growing cold-tolerant salad greens and herbs under protection.

Pest Management in Winter Structures

Enclosed growing spaces can harbor overwintering pests like aphids, whiteflies, and spider mites. Inspect plants regularly and address any pest issues promptly before populations explode. Maintain good air circulation to prevent fungal diseases in humid winter conditions.

Equipment Maintenance and Preparation

Tool Care During Downtime

Use quiet December days to clean, sharpen, and oil garden tools. Remove rust from metal tools, sharpen pruning shears and loppers, oil wooden handles, and repair any broken equipment. Proper maintenance extends tool life and ensures they're ready for spring work.

Planning Infrastructure Improvements

Consider what garden infrastructure projects you'd like to complete before the growing season begins. This might include building raised beds, installing irrigation systems, constructing trellises, or improving compost bins. Order materials now so you're ready when weather permits outdoor work.

December Garden Wildlife Support

Your garden provides important winter habitat for beneficial wildlife. Leave some seed heads standing for birds, maintain brush piles for shelter, and keep bird feeders stocked. A wildlife-friendly winter garden supports the ecosystem that will help control pests in the growing season ahead.

Preparing for Spring Success

While December and January may seem dormant, they're actually crucial planning and preparation months. The care you provide now - protecting outdoor plants, maintaining healthy houseplants, starting seeds at the right time, and planning improvements - sets the foundation for a successful growing season ahead. Embrace these quieter months as an opportunity to refine your skills, expand your knowledge, and dream about the abundant garden that awaits in spring.

Growing in December

When the winter December atmosphere arrives, it's as if the entire garden slowly falls asleep under the reign of snowflakes. Don't be fooled by this seemingly apparent phenomenon. December brings important tasks that must be completed before the onset of harsh winter. The main role is played by woody plants, which deserve your attention, but we must not forget about winter vegetables.

Tree care over winter

If December weather is more merciful to us and has kept its snowy blanket hidden away for now, we must take care of thermal insulation ourselves, for example with straw, coniferous branches or dry leaves. Trees are protected from freezing thanks to snow cover, which is why it's important to replace its absence. In the opposite case, the procedure is completely different. If a thick layer of wet and therefore heavy snow falls, it's necessary to shake off this accumulation from young trees. There is a danger of broken branches. For these reasons, it's good to tie coniferous trees into a so-called cone shape. In the case of shrubs, it's good to hide those that can be placed under a roof. Where a hard crust forms on the surface of the fallen snow layer, it's important to protect woody plants from wildlife browsing much higher up. December brings the best time for taking scions from fruit trees. If you have a medlar in your garden, you know well that the ideal time for its harvest has arrived. Medlar tastes best after freezing.

Don't forget about watering

Once deciduous trees and shrubs shed their last leaf, they enter a dormant state when all life processes slow down. This reduces demands for water irrigation and they virtually sail through the entire winter period unnoticed, without you having to intervene in any way. However, this doesn't apply to evergreen plants. They, on the contrary, suffer from thirst and drying out, so give them a portion of watering even in winter. We water during more favorable weather. Azaleas and rhododendrons and similar non-deciduous broadleaves suffer most from drought. If we focus our attention on typical conifers in the form of pine or spruce, we don't need to worry too much here. They are known to be highly resistant woody plants.

Winter vegetables

December offers itself for forcing parsley greens, herbs and cress, ensuring a constant fresh supply of tasty ingredients in your kitchen. There is a whole range of perennial vegetables intended for winter cultivation. Thanks to tubers and roots hidden under the soil layer, they can grow despite the adversity of winter weather and sprout again in spring. If you still don't know which vegetables these might be, we'll give you a hint. These include popular horseradish, asparagus or Jerusalem artichoke. We also find some representatives of biennial vegetables such as parsley, black salsify, parsnip. Likewise, all bulb plants are frost-resistant.

What can be planted in December - vegetables

If the weather is favorable and resembles autumn conditions, you can sow carrots, root parsley as well as leaf parsley, parsnips, onions, shallots, garlic or pointed cabbage in your beds. Spinach and curly kale are also very hardy.

Sowing Pelargoniums

Give your garden a touch of harmony with beautiful pelargonium flowers and take advantage of December to sow them. Use peat blocks, which are proven to be the most suitable medium. Once the seedlings grow, simply transplant them together with the block into a larger container. If for some reason you don't prefer peat blocks, you can use shallow trays with sterile, steamed substrate consisting of peat, garden soil and sand. For germination itself, a temperature of around 20°C and constantly moist substrate are required.

Final Adjustments

If you didn't manage to weed and dig over the beds in the previous month, December is your last chance to do so. Likewise, you can turn over the compost and remove herbs for forcing into pots and place them in a warmer location. In December, you can also rake up leaves and compost them.

Average December values: temperature: -5.3°C precipitation: 37 mm sunshine: 25 hours

December weather lore: Cold December - early spring. , Lucy drinks the nights but adds no daylight.