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
- Trim 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 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
- 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
On the forum: share your growing tips with other gardeners and ask for advice
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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 corn salad 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
- Plant blueberry bushes into acid soil
On the forum: which fruit and veg varieties are you growing?
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
- Pour water over the greenhouse floor every morning during hot weather to increase humidity
- 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
- Take leaf cuttings from succulents, such as echeverias, crassula and sedums
- Start watering dormant cyclamen to bring them back into growth after their summer rest
- Plant 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
- Take leaf cuttings from houseplants, including begonias, African violets and Cape primroses
Fragrant Narcissus for Christmas
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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
- Tackle problem lawn weeds, digging them out or applying a lawn weedkiller
- 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
On the forum: join in the discussion, share your wisdom and ask for help
Summer prune Wisteria
Buy a pair of mature 6.5L citrus trees, one each of lemon 'Eureka' and orange 'Navelina' or two of one variety, hardy to -5ºC, plus free strawberry runners, worth £12.99.
Use code: EGW174
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Astrantia are a much-loved cottage garden favourite. Starry pincushion flowers bloom for months on end followed by interesting seed heads. Available in a range of colours.
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We invite you to enjoy a special online event with Monty Don and Editor, Lucy Hall. Monty will share tales from a life of gardening and reveal what goes on behind the scenes at Longmeadow.
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