What to do during July in your garden and greenhouse.

Your monthly gardening checklists

Flowers

Geranium x magnificum

Cut back geraniums and other summer perennials.

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Fruit and veg

Protect brassicas from cabbage white butterflies with fine netting

Greenhouse

  • Open greenhouse vents and doors on warm days to improve air circulation
  • Continue pinching out any side shoots growing from the leaf joints of cordon tomatoes
  • Take cuttings from fuchsias, coleus, pelargoniums, marguerites and other tender perennials
  • Water tomatoes daily to prevent drying out, which can lead to split fruits and blossom end rot
  • Order cold-stored potato tubers for planting in a greenhouse or cool porch next month, to harvest at Christmas
  • Damp down the greenhouse floor each morning on hot days to increase humidity
  • Be vigilant for aphids, vine weevils and other pests, and treat immediately so infestations don't get out of hand
  • Feed tomatoes, chillies and cucumbers with high-potash tomato fertiliser every week to encourage fruiting
  • Install a reservoir watering system, so thirsty plants such as tomatoes don't dry out
  • Regularly sweep greenhouse staging and floors to reduce debris that can harbour pests and diseases
  • Train the main stem of cucumbers up supports and pinch out sideshoots two leaves after a flower or fruit

Damp down greenhouses on hot days to increase humidity

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Garden maintenance

  • Compost your kitchen and garden waste, chopping up and mixing the contents to speed up decomposition
  • Top up bird baths, ponds and water features during hot weather
  • Water new trees, shrubs and perennials planted in spring, to help them through dry spells
  • Trim conifers and other garden hedges
  • Scoop out any floating pondweed and algae from pools and water features
  • Keep mowing lawns regularly, but raise the cutting height to leave the grass longer during dry weather
  • Water hanging baskets and patio containers daily, in the morning or evening
  • Deadhead bedding plants, sweet peas and annuals every few days to encourage more flowers
  • Set up an automatic watering system to look after greenhouse crops, pots and baskets if you're going on holiday
  • Make your own liquid feed from comfrey plants
  • Apply tomato feed fortnightly to crops in pots and growing bags, such as tomatoes and chillies, to encourage fruiting
  • Trim lavender after flowering to keep plants compact and bushy, but avoid cutting into old wood
  • Be on the lookout for developing pest problems and take action straight away

Trim conifers to maintain an even shape.

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
  • 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

Offers

Gardening offers
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Primula veris 'Lime with Orange'

Some of the first flowering plants to bloom each year (March to May), primulas such as 'Lime with Orange' are indispensable for providing early colour and cheer. Perfect for a container display or window box.
£18£36

Supplied as 3 x 9cm pots

Gardening offers
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BotaniQua Hosta Vase Collection

Grow your very own Hosta in a glass vase and watch with fascination as you see the roots develop. So easy to grow, they care for themselves, producing beautiful leaves which compliment every type of home - just keep an eye on the water level and top up as required.
£28£45

Supplied as 3 x bare root plants with stylish fluted glass vases (14cm tall & 9cm wide)