What to do during August in your garden and greenhouse.
Your monthly gardening checklists
Flowers
- Collect seeds as they ripen, from plants such as aquilegias, sweet peas and love-in-a-mist, choosing a dry day
- Deadhead dahlias and other perennials to encourage a constant display of blooms
- Keep camellias and rhododendrons well watered through late summer while their flower buds are forming
- Prune lavender once flowering is over to maintain a compact, bushy shape, but avoid cutting into old wood
- Prune rambling roses, removing up to a third of stems that have flowered, and tie the rest to supports
- Keep pots and hanging baskets flowering by watering and deadheading regularly, and add tomato feed fortnightly
- Take softwood cuttings of woody herbs, including lavender and hyssop, choosing non-flowering shoots
- Sow hardy annuals in sunny spots to provide early summer colour next year
- Set up an automatic watering system for pots and hanging baskets if you're going away on holiday - in the case of a hosepipe ban, drip or trickle irrigation systems are usually exempt, check your local water board for restrictions
- Strim or mow areas of wildflower meadow, now that the plants have scattered their seeds
- Take softwood cuttings from penstemons, choosing healthy, vigorous, non-flowering shoots
- Remove any spent hardy annuals if you don't want them to self-seed
- Plant autumn bulbs, such as colchicums, sternbergia and nerines, in pots and borders
Fruit and veg
- Be vigilant for signs of tomato and potato blight, removing affected plants immediately to prevent spread
- Summer prune both free-standing and trained apple trees, to encourage good fruiting in future years
- Plant well-rooted strawberry runners into new beds
- Pinch out the tops of outdoor tomatoes, as further flowers are unlikely to produce fruits that have time to ripen
- Order saffron crocus bulbs (Crocus sativus) to plant in September, so you can harvest your own saffron this autumn
- Use netting or fleece to protect blackberries and autumn raspberries from birds
- Lift onions and shallots once their tops die down, then leave to dry in the sun
- Cut back leaves on grapevines to let the sun ripen the fruits
- Sow hardy crops such as land cress, rocket and lamb's lettuce for winter pickings
- Harvest fresh herbs to freeze in ice cubes for winter use, or to hang up and dry, then store in jars
- Plant a kiwi plant, to climb over a trellis, fence or arbour
- Water crops regularly, especially during hot weather, use water from a water butt if possible. In periods of drought, there may be a hosepipe ban so water your crops with a watering can
- Plant blueberry bushes into acid soil
Greenhouse
- Set up a capillary matting system to ensure plants have enough water if you're going away on holiday
- Plant cold-stored potato tubers in large tubs in a greenhouse or cool porch, for harvesting at Christmas
- Pouring water over the greenhouse floor every morning during hot weather can help to increase humidity - during periods of drought try to use grey water to help reduce mains water use
- Plant up pots with 'Paper White' narcissus bulbs for fragrant indoor displays this Christmas
- Remove the lower leaves of cordon tomatoes up to the lowest truss, to let more light and air reach the fruits
- Start watering dormant cyclamen to bring them back into growth after their summer rest
- Plant autumn flowering bulbs, such as nerines, lachenalia and veltheimia in pots indoors, for autumn and winter colour
- Look out for pests and diseases on greenhouse plants, and treat any you find immediately
- Harvest tomatoes, cucumbers and chillies regularly to encourage more fruits to form
- Tackle vine weevil infestations by watering pots with a solution of biological control nematodes
- Shade delicate plants in the greenhouse to avoid sun scorch on hot days
House plants
- Feed houseplants once a week with liquid fertiliser, continuing through to autumn
- Water your house plants more regularly as the temperatures warm and light levels increase, check the soil before watering. Take a look at our guide to watering house plants
- Repot any houseplants that have become top heavy or pot bound into larger containers
- Ensure house plants are not getting scorched by summer sunshine. Either move further from the window or choose house plants that will thrive in a sunny spot
- Some house plants, like snake plants, are particularly prone to collecting dust on their leaves. So be sure to give these a wipe regularly
- Put houseplants outside for the summer in a warm, sheltered spot to enjoy the fresh air and extra light
- Take leaf cuttings from houseplants, including African violets, begonias and Cape primroses
- Take leaf cuttings from succulents, such as echeverias, crassula and sedums
- Check your house plants for pests like aphids, scale insects, thrips and mealybugs
- Take large-leaved houseplants into the garden and hose them down to clean off accumulated dust
For more house plant advice and inspiration visit our Growing and caring for house plants page
Garden maintenance
- Cut laurel hedges with secateurs rather than a hedgetrimmer, to avoid half-cut leaves that turn brown
- Clear weeds from cracks in paving and driveways before they get established
- Remove problem lawn weeds, digging them out
- Sow green manure to fill any bare ground
- Summer prune wisteria by shortening all long sideshoots to about 20cm
- Keep deadheading border plants, unless you want to collect their seeds
- Remove suckers from roses or around the base of trees
- Collect seeds and ripe seed pods from your favourite flowers and vegetables
- Prop up any clumps of tall border plants that are starting to flop, using canes and string, or twiggy sticks
- Prepare soil for sowing a lawn or laying turf during September and October
- Go on regular snail hunts, especially on damp evenings, to reduce populations
- Turn compost to speed up decomposition
- During periods of drought or dry weather, be sure to water wisely, listen to this podcast episode with Arit Anderson for some top tips
Offers
Gardening offers
Hyacinth 'White Pearl' & 'Pink Pearl'
All the glitter and tinsel of Christmas can't compare with the sparkle and fragrance that indoor hyacinths provide. When the ground outside is frozen, your loved ones will really appreciate the simple pleasure of a basket of scented hyacinths in their home this winter. Deceptively simple, yet unerringly stylish, our bestselling hyacinths are guaranteed to give stunning results.
£7.99£19.99
Supplied as 5 bulbs (choose from Hyacinth 'White Pearl' or 'Pink Pearl') in a 16cm ceramic pot
Gardening offers
Save 20% on Camellia ‘Yuletide’
Dubbed the 'Christmas Camellia,' Camellia sasanqua ‘Yuletide’ blooms from November to February with scarlet flowers and golden stamens, brightening gardens and indoor vases.
£24£30
Supplied as 3 x 8cm pots
Gardening offers
Standard Holly Trees with 'Pinecone' Planters
Create stunning festive displays, frame entrances or adorn patios with this pair of standard holly trees, with decorative pots.
£39.96£99.96
Supplied as 2 x 80-100cm Standards with 2 x 34cm Pots