December in the garden: Embrace the Structure and Winter Glow

As the days reach their shortest and temperatures settle, the garden enters a period of rest—but not entirely of stillness. While the layers of herbaceous perennials have receded, revealing the bare bones of the landscape, it’s the structure provided by evergreens and hardscaping that truly comes into its own. These elements provide essential stability and form throughout the seasons.

Don’t mistake the cold for a lack of colour! Stepping out on a clear, frosty, sunny day is still a pleasure. The winter garden offers its own unique palette, featuring the vibrant blooms of winter-flowering heathers and the cheerful yellow of Jasminum nudiflorum and Hamamelis mollis. Further colour is supplied by the jewels of the season: the berries of shrubs like Callicarpa and Ilex aquifolium (holly), and the stunning bark of trees such as Betula (birch) and the peeling cinnamon tones of Acer griseum.

Flowers

• Continue to cut back faded herbaceous perennials and add them to the compost heap.
• If the weather remains mild, you can still lift and divide herbaceous perennials. This will increase stocks and revive tired or poorly flowering clumps.
• Root cuttings can be taken now, such as Papaver (perennial poppies), Phlox and Anemones.
• Order seed catalogues, if you have not done so already, to select next year’s bedding and perennial choices.
• Bring forced bulbs into a warm room to encourage them to flower.

Fruit and veg

• Place straw around the base of parsnips to prevent soil freezing, which can make harvesting difficult.
• Winter prune large fruit trees to control their shape and size, and to increase fruiting productivity for next year.
• Plan next year’s crops and order seeds.

Greenhouse

• Pick faded leaves and dead flowers regularly from plants overwintering in the greenhouse, such as pelargoniums.
• Check that greenhouse heaters are working.
• If the weather is mild, ventilate the greenhouse.

Garden maintenance

• Scoop fallen leaves and debris from ponds, leave them on the side so pond life can escape, and then add them to the compost bin.
• Insulate outdoor taps and prevent ponds from freezing.
• Protect terracotta pots from cracking in freezing weather by either bringing them indoors or wrapping them in bubble polythene.
• Raise outdoor patio containers onto feet or bricks to avoid them sitting in the winter wet.
• Rake up fallen leaves in borders that could be harbouring slugs and other pests.
• Clean paths to prevent them from becoming slippery and repair sheds, fences and trellises.
• Avoid walking on lawns covered with frost.

As the colours change and the evenings grow darker, the rhythm of the garden shifts. While we naturally spend less time lingering outside, October is not a time to rest; it’s a time to plan. Main activities will revolve around clearing up after summer and preparing for the winter and spring ahead.

Here is your October action plan to keep your garden in top condition:

Flowers

• Plant drifts of spring bulbs informally in a lawn, such as crocuses and daffodils
• Lift tender Cannas and Dahlias to avoid frost damage, dry off the tubers and store in cool dark conditions until spring
• Plant up pots with winter colour, such as Cyclamen, Winter Pansies and Skimmia
• Lift and pot up tender perennials to protect them over winter
• Plant evergreen shrubs and conifer hedges while the soil is still warm
• Collect seeds from hardy perennials and sow straight away
• Take hardwood cuttings from ornamental trees and shrubs
• Reduce the height of shrub roses to avoid wind-rock damage over winter

Fruit and veg

• Take cuttings of shrubby herbs, such as Rosemary, Lemon Verbena and Thyme
• Cover salad plants with cloches to prolong cropping
• Plant garlic cloves in a sunny well-drained spot, 15cm apart, with their tip 5cm below the surface
• Wrap grease bands around the trunks of apple, pear, cherry and plum trees to trap the crawling female winter moth
• Cut autumn-fruiting raspberries down to the ground after harvesting
• Order bare-root fruit trees and bushes for planting from late autumn to early spring

Greenhouse

• Clean out the greenhouse to get rid of debris that can harbour overwintering pests and diseases
• Wash greenhouse glazing to let in as much of the weaker autumn daylight as possible
• Sow quick-growing micro-greens, such as kale and mustard, for nutrient-rich pickings in just a few weeks
• Line greenhouse glazing with bubble insulation, as night-time temperatures start to drop
• Water plants more sparingly as conditions turn cooler and the days get shorter
• Sow sweet peas in deep pots for early flowers next summer
• Inspect plants you bring into the greenhouse over winter for any pests and diseases

Garden maintenance

• Rake up fallen leaves from lawns, borders, driveways and paths, and store in bin bags to rot down into leaf mould
• Spike compacted lawns and brush either sharp sand or horticultural grit into the holes to help improve drainage
• Apply an autumn lawn feed to revive the grass after the rigours of summer
• Empty any pots that aren’t frost proof and store in a garage or shed over winter

Although this is traditionally the holiday season, it is important to keep on top of some of the routine garden jobs, such as deadheading, weeding and watering. This could be a dry month in which case watering is essential.

Here is a list of jobs to do this month.

Flowers

• Summer prune wisteria after flowering by removing all the whippy side-shoots from the main branch framework to about five leaves from the main stem;
• Prune rambling roses after flowering;
• Trim lavender once the flowers have faded to maintain a compact, bushy shape, but avoid cutting into old wood;
• Deadhead roses, dahlias and perennials to encourage a constant display of flowers;
• Feed and regularly water plants in containers;
• Take cuttings from tender perennials such as pelargoniums, fuchsias and verbena;
• Collect ripening seed from plants such as sweet peas and love-in-a-mist that you wish to propagate;
• Plant autumn bulbs such as colchicums and nerines in pots and borders;
• Start planting early-flowering biennials such as wallflowers which were sown under cover earlier this year;

Fruit and Veg

• Lift and pot up new strawberry plants, and keep them well watered;
• Pick courgettes regularly so they don’t turn into marrows;
• Divide clumps of chives;
• Ensure that your fruit crops aren’t eaten by the birds by covering them with netting, ensuring the netting stands well clear of the fruit;

Greenhouse

• Water and feed tomatoes regularly, and remove lower leaves to allow the fruits to ripen;
• Be vigilant for signs of tomato and potato blight, removing affected plants immediately to prevent spread;
• Pinch out the tops of outdoor tomatoes, as further flowers are unlikely to produce fruits that have time to ripen;

Garden Maintenance

• Make sure birds have water in dry spells;
• Mow less frequently if the weather is hot and dry;
• Strim or mow areas of wildflower meadow, now that the plants have scattered their seeds;
• Clear weeds from cracks in paving and driveways before they get established;
• Now is the time to look at your borders and note any gaps or congested areas that you’ll want to rectify later on in the year;
• Order spring-flowering bulbs now as stock of the more popular varieties may not be available later in the season. You can start planting bulbs such as narcissi, alliums and crocus from September. Leave planting of tulips to later in November to help prevent problems such as tulip fire as soils are colder and fungal spores are less likely to spread;

Missed the Chelsea Chop? Embrace the Hampton Hack!

If you missed the window for the Chelsea Chop in May, don’t worry! That handy technique, timed with the Chelsea Flower Show, helps extend the flowering season of herbaceous plants.

But it’s not too late to give your garden a boost. You can rejuvenate tired July borders by using the Hampton Hack. This method coincides with the Hampton Court Palace Garden Festival and is perfect for revitalising your plants now.

Shrubs that respond well to the Hampton hack include:

Philadelphus
Weigela
Helianthemums

These can all take quite tough mid-summer pruning, which will prolong their life and stop them from becoming unattractively untidy or too big for their boots.

Herbaceous plants:

Alchemilla mollis
Astrantias
Herbaceous Geraniums
Nepeta

The degree of cutting back is specific to each species but the closer to the flowering time you prune, the greater the delay in flowering. Doing the ‘Hampton Hack’ can delay the flowering of perennials by four to six weeks. You can either prune all the stems on a clump, which delays all the flowers, or just half of them, which spreads the plant’s flowering over a longer period. This can have some positive results:

The plants are not so tall and leggy
They need less staking
The flowers are smaller but more numerous

This happens because the removal of the top shoots enables the side shoots to branch out (the top shoots would normally inhibit the side shoots by producing hormones in a process called apical dominance). Using this method, along with regular feeding and watering, ensures beds and borders look tidy throughout summer.

After Lupins and Delphiniums have finished flowering, chop them down to about 30 cm in height, apply a mulch around their base and give them a generous drink of water. They’ll start into growth again and may produce additional smaller flowers on shorter stems later on in the year, and you’ll have new foliage to look at instead of a yellowing mess.

June is a wonderful time in the garden, the weather is warmer and it’s encouraging flowers to appear in abundance. Here are a few tasks to keep on top of at this time of the year:

Flowers

• Stake plants that are prone to flopping;
• Continue planting summer bedding in pots and borders, watering them regularly to help plants establish quickly;
• Tie in new stems of climbing and rambling roses horizontally to supports, this will encourage more flowers;
• Give a liquid feed to pots and hanging baskets every few weeks to encourage flowering;
• Prune late-spring or early-summer shrubs after flowering, such as Kerria and Philadelphus, and thin out any older stems;

Fruit and veg

• Plant out sweetcorn after hardening off, arranging plants in blocks to assist with pollination;
• Cover ripening fruits with netting or fleece to protect them from hungry birds;
• Water vegetables and fruit in containers regularly, especially during dry sunny weather;
• Go on regular snail and slug hunts, especially on damp evenings, to reduce numbers;
• Apply tomato feed regularly to fruiting vegetable crops, including tomatoes, courgettes, and chillies;

Greenhouse

• Sow biennials such as foxgloves and wallflowers in seed trays;
• Shade greenhouses to keep temperatures down on hot days and open vents and doors on warm days. Damping down your greenhouse on hot days will help with increasing humidity;
• Sow herbs such as coriander, parsley and basil in pots to grow on the kitchen windowsill;
• Pinch out the side-shoots of cordon tomatoes regularly and apply a weekly feed;
• Water plants daily in warm weather, ideally in the evening or early morning. Avoid splashing the foliage as sunlight can burn leaves with water sitting on them;
• Introduce biological controls to the greenhouse if you have pests such as whitefly or red spider mites;
• Harden off hanging baskets and pots of summer bedding that have been growing in the greenhouse;
• If your strawberries need a little help ripening, bring them in to the warmth of the greenhouse. This will also protect them against bird, slug and snail damage;

Garden maintenance

• Keep weeding and dead-heading plants to ensure your borders stay looking at their best;
• Continue watering any new plants until they’re well established;
• Water newly laid lawn regularly, for at least the first month;
• Before starting any trimming or pruning tasks, check hedges and shrubs for nesting birds in order that you don’t disturb them;
• Treat pots with vine weevil control if you’ve previously had problems with this pest. The larvae become active this month, feeding on plant roots, particularly in pots, and the adults feed on the leaves;
• Dig out perennial weeds such as dandelions as soon as you spot them;
• Feed lawns with a liquid or granular lawn fertiliser;
• Remove pond weed as it can quickly get out of control as the weather gets warmer;
• Place houseplants outside for the summer in a warm, sheltered spot to enjoy the fresh air and extra light;