December Gardening Tasks

December is here and it’s time to focus on key gardening tasks for the last month of the year. Sow summer vegetables like pumpkins and cucumbers, and feed fruiting plants with potassium-rich fertiliser. Keep your garden thriving with regular watering, mulch renewal, and care for your roses. After the hard work, enjoy a refreshing cocktail by the pool to unwind.

General Tasks

• Weed the garden. After weeding place a layer of organic mulch over every last inch of soil. Mulching not only saves water and your time when you’re desperately busy with other tasks, but will also provide a professional and well cared for look and will display existing plants to their best advantage.
• Plant versatile herbs like basil, mint, and lavender in containers. These herbs not only enhance meals but can also act as natural insect repellents. Shift the pots to sunny or shaded areas as needed for optimal growth.  
• Maintain consistent watering to keep hydrangeas looking lush.  
• Check the vegetables daily for harvesting, especially quick producers like green beans. The longer the fruit stays on the plant, the less productive it is.
• Fertilise green leafy vegetables to encourage healthy new leaves.
• Renew mulch; it encourages soil life, keeps the soil cool and reduces weeds
• Stake tomatoes, earth-up potatoes, and support vining squashes or place fruit on a layer of mulch or a brick to prevent it from rotting.
• Stake tall plants, such as dahlias, to prevent them from toppling over.

Sowing

• Start sowing seeds of biennials like primulas, foxgloves, and aquilegias for vibrant displays next year. 

• For summer crops, sow seeds of pumpkins, cucumbers, sweetcorn, maize, and chillies. Chilli seeds require warmth to germinate, so use a heat mat or greenhouse. Once seedlings develop their first true leaves, transplant them into larger containers or garden beds.

Planting 

• Choose plants that thrive in different garden conditions: 

• Cerastium tomentosum for hardy, low-maintenance groundcover. 

• Acorus gramineus ‘Golden Edge’ for damp or waterlogged areas. 

• Ruttya fruticosa for its unique tubular blooms that attract pollinators. 

• Add vibrant options like salvias, tickseed (Coreopsis grandiflora), and lisianthus (Eustoma grandiflorum) to beds or pots for an eye-catching summer display. 

Feeding 

• Use potassium-rich fertilisers to support fruiting plants. These encourage strong, healthy fruit development. 

• Feed citrus trees with a balanced fertiliser in the middle of the season. Mulch around their base and water thoroughly to ensure even nutrient absorption. 

Transplanting

• Transplant seedlings when they reach 10-15 cm tall and have developed their first set of true leaves. For brassicas, prepare the soil by incorporating compost and well-rotted manure, spacing plants 45-60 cm apart to allow for full growth. 

Pruning

• Trim hedges to keep them neat and in shape.

• Regularly deadhead flowering plants, such as pelargoniums, to encourage continuous blooming. Pinch the growing tips of young annuals and perennials to promote bushier growth. 

Lawns 

• Fertilise lawns with a specialised lawn fertiliser and water deeply to keep grass lush and green during summer. 

• Repair bare spots by laying instant lawn sods. For fungal issues like dollar spot, brown patch, or fairy rings, treat affected areas with a suitable fungicide. 

Pests 

• Keep an eye out for common summer pests, including red spider mite, fruit flies, and whiteflies. Organic sprays can help manage infestations without harming beneficial insects. 

• To prevent diseases like blight and mildew, water plants early in the day and ensure leaves dry before evening. 

• Before heading on holiday, begin a pest control programme using organic options such as Ludwig’s Insect Spray or Margaret Roberts Organic Fungicide to minimise issues during your absence. 

Rose tasks for December

• Keep roses healthy by watering consistently and applying Vigorosa fertiliser in mid-December. 

• Prevent pests and diseases by spraying roses with a combination of Ludwig’s Insect Spray and Chronos. 

• If you’re going on holiday, skip fertilising to avoid encouraging growth while you’re away. Instead, apply a thick mulch layer and spray the plants before leaving. On your return, water deeply and tidy the plants to encourage fresh growth. 

December Veggie Sowing Guide 

• Prepare for a bountiful harvest by sowing summer vegetables like pumpkins, cucumbers, sweetcorn, chillies, and leafy greens.  

• Maintain consistent watering and apply organic pest control to ensure strong, healthy growth.

Highveld and KwaZulu-Natal Midlands 

Asparagus, bush and runner beans, broccoli, cabbage, cauliflower, celery, cucumbers, Swiss chard 

Middleveld (Tshwane and other less frosty areas) 

Asparagus, bush and runner beans, beetroot, cucumbers, pumpkins, sweetcorn, bush and trailing squash, sweet melons, swiss chard, tomatoes 

Eastern Cape and Little Karoo 

Asparagus, bush and runner beans, beetroot, broccoli, cabbage, carrots, cauliflower, cucumbers, radishes, sweetcorn, bush and trailing squashes 

Northern Cape and Great Karoo 

Asparagus, bush and runner beans, broccoli, cabbage, cauliflower, cucumbers, pumpkins, Swiss chard 

Western Cape (and southern coast) 

Asparagus, bush and runner beans, broccoli, cabbage, cauliflower, lettuce, sweetcorn, sweet melons, bush and trailing squashes 

Lowveld and KwaZulu-Natal coast 

Rocket, sweet peppers, sweet potato tuber 

Veggie garden tasks for December

• Establish a regular watering schedule. Vegetables like consistency, not over- or under-watering.  

• Keep on succession planting of tomatoes, bush beans, beetroot and radishes. This is the last month for tomatoes and beetroot.  

• Feed fruiting plants with a potassium-rich fertiliser. 

• Pick all the ripe vegetables as well as tomatoes that are turning. They will ripen indoors.  

• Pinch off the growing tips of vine vegetables. 

• Arrange for the garden to be watered twice a week in the absence of rain. 

• Put up temporary shade cloth, especially if the veggies won’t be watered regularly. 

Projects

Looking for some ideas for kids to do this holiday season? Run Marble, Run – DIY for Kids

Recipes

With the holiday season here, here are some pool party cocktail ideas