Summer Gardening Jobs: Complete UK Checklist

Summer is when British gardens really shine. The long days from June to August bring the best colour, the biggest harvests and loads of wildlife. They also bring the most work: watering, deadheading, picking and keeping everything in check. Here’s what to do, and when.

Watering

Watering is the biggest summer job. Get it right and everything else is easier.

How much and how often

Give beds a deep soak once or twice a week rather than a light sprinkle every day. A good soak gets water down to the roots. Little sprinkles keep roots near the surface, where they dry out fast.

Water early in the morning or in the evening, when less is lost to the sun. Morning is best, as the leaves dry quickly. Evening watering is fine but can bring out the slugs.

What needs water most

New trees, shrubs and perennials need watering through their whole first summer, as their roots haven’t spread yet.

Pots and hanging baskets dry out fastest. Check them every day and water until it runs out of the bottom. Big pots dry out more slowly than small ones.

Vegetables need steady moisture, especially when flowering and fruiting. Uneven watering makes tomatoes split, lettuce bolt and beans drop their flowers.

Established trees and shrubs rarely need watering once they’ve been in for a couple of years. For more ideas, see our guide to water-efficient gardening.

Gardener’s tip: Push your finger into the soil. If it’s dry a few centimetres down, water. If it’s damp, leave it.

Pots dry out fastest of all, so check them every day in summer. Keep watering until it runs out of the bottom.

Lawn care

Mowing

Mow weekly through June and July. In a heatwave or long dry spell, raise the blades and mow less often. Longer grass shades its roots and copes with dry weather better.

Don’t mow a brown lawn. In a long drought, grass goes brown and rests. It’s not dead, and it greens up again once the rain returns. Mowing it just causes damage.

Feeding

Give a summer lawn feed in June if you like. Don’t feed in a heatwave, as feed can scorch dry grass.

Watering the lawn

Most lawns bounce back from drought without any watering. If you do water, give it a good soak once a week rather than a little every day.

After a drought

Brown patches recover on their own once it rains. Don’t scarify, feed or reseed until the grass is growing well again. By September it usually looks green without any help.

Borders and beds

Deadheading

Deadhead every few days while plants are in full flower. Taking off old flowers stops the plant making seed, so it makes more flowers instead.

Roses: cut the old flower back to the first outward-facing leaf with five leaflets.

Dahlias: snip off old heads just below the flower. New buds form further down the stem.

Sweet peas: pick every flower, including faded ones. Once they set seed, they stop flowering.

Weeding

Keep on top of weeds. Annual weeds set seed quickly, and one plant can drop thousands. Hoe on dry days so the weeds shrivel on the surface. In wet weather, pull them by hand instead, as hoed weeds can root again.

Staking and tying

Tall perennials like delphiniums, hollyhocks and dahlias can lean and snap in wind and rain. Tie stems loosely to canes with soft twine, leaving room for them to thicken.

Late summer planting

In August, plant autumn-flowering perennials like Japanese anemones, sedums, asters and rudbeckia. Water them in well so they settle before winter.

Deadheading roses every few days keeps the flowers coming well into autumn.

Pruning

Shrubs that have finished flowering

Prune shrubs that flowered in spring and early summer straight after they finish:

• Philadelphus (mock orange): cut flowered shoots back to strong new growth lower down
• Deutzia: take out about a third of the oldest stems at the base
• Weigela: cut flowered branches back to a young side shoot
• Lilac: just deadhead, removing the old flower heads

Wisteria summer pruning

Prune wisteria in July or August. Cut this year’s long, whippy green shoots back to five or six leaves from the main branches. This keeps it tidy and helps it make flowers for next year. In winter, shorten the same shoots again to two or three buds.

Cut the long, whippy green shoots back to five or six leaves in July or August. It keeps the plant tidy and sets up next year’s flowers.

Hedge trimming

Trim formal hedges in early summer and again in late summer:

Check for nesting birds first. It’s against the law to disturb an active nest. If you find one, wait until the chicks have flown.

Lavender

Trim lavender straight after it flowers, usually late July or August. Cut off the flower stalks and a little of the leafy growth, shaping it into a dome. Don’t cut into bare, woody stems, as lavender won’t grow back from old wood.

Harvesting

Summer is picking season. The more you pick, the more most plants give you.

Vegetables

Courgettes: pick at 15 to 20cm long. Check every other day, as they grow fast in warm weather. Leave one on and it becomes a marrow, and the plant slows down.

Tomatoes: pick when fully coloured and slightly soft. Pinch out sideshoots weekly on cordon types. Feed with tomato feed once the first fruits set, as the label says. See our tomato growing guide for the full method.

Runner and French beans: pick every few days while the pods are young and tender. Old pods left on tell the plant to stop flowering.

Potatoes: lift first earlies from June, second earlies from July and maincrops from August. For maincrops, wait until the leaves yellow and die back.

Salads: pick as you need them. Cut-and-come-again types give several pickings from one sowing. Sow more every few weeks for a steady supply.

Soft fruit

Strawberries: pick when fully red, checking every other day. Remove runners unless you want new plants. Once fruiting finishes, cut back the old leaves and clear away the straw. Our strawberry growing guide has the details.

Raspberries: pick summer-fruiting types from late June. After picking, cut the fruited canes to the ground and tie in the new ones for next year.

Blackcurrants, gooseberries and redcurrants ripen from late June into July. Pick whole strings of currants rather than single berries.

Pick courgettes small, beans young and tomatoes fully ripe to keep plants cropping.

Greenhouse jobs

Ventilation and shading

Open the vents and door on warm days. Very hot greenhouses stress plants and stop fruit setting. Use shading paint or shade netting from June.

Damp down on hot mornings by wetting the floor. It cools the air and makes it more humid, which plants like and spider mites don’t.

Watering and feeding

Greenhouse plants need watering every day in summer, and twice in a heatwave. Tomatoes, cucumbers, peppers and aubergines are all thirsty.

Feed tomatoes and peppers with a high-potash liquid feed once the first fruits set. Give cucumbers a balanced feed. Yellowing between the veins of lower tomato leaves can mean they’re short of magnesium. A magnesium sulphate (Epsom salts) feed, used as the pack says, helps.

Pests to watch

Watch for red spider mite in hot, dry weather. Fine webbing under leaves is the giveaway. Damping down and misting help keep them at bay.

Whitefly gathers under tomato and pepper leaves. Hang yellow sticky traps to keep an eye on numbers. The tiny parasitic wasp Encarsia formosa is a good chemical-free control.

Wildlife

Water for wildlife

Put out shallow dishes of water for birds, hedgehogs and insects. Add a few stones so insects can land safely. Refresh it daily.

Leave some areas wild

Let a patch of lawn grow long through summer. It’s a home for grasshoppers, beetles and small mammals, and wildflowers bring in lots of pollinators. See our guide to creating a mini meadow.

Helping hedgehogs

Hedgehogs are busiest from June to September. Make 13cm gaps at the bottom of fences so they can move between gardens. In dry spells, put out a shallow dish of water and some meaty cat food. Never give them bread or milk.

Pond care

Topping up

Ponds lose water fast in summer. Top up with rainwater from a water butt if you can. Tap water adds nutrients that feed algae.

Blanketweed

Blanketweed loves summer sun and warmth. Twirl it out with a stick or cane. Some gardeners also use barley straw, which may help slow algae down.

Oxygenating plants

Thin out oxygenating plants like hornwort if they’re taking over the pond. Pull out the extra with a net and leave it by the pond overnight so creatures can crawl back in.

Top up summer ponds with rainwater and keep pulling out blanketweed.

Tools and other jobs

Before you go on holiday

Water everything well, move pots into the shade and group them together so they shelter each other. Ask a neighbour to water the pots and pick any crops. Mow the lawn the day before you go.

Composting

Summer makes lots of green waste. Keep the heap balanced with roughly equal amounts of green and brown material. Grass clippings are very green, so mix them with shredded cardboard, straw or dry leaves. Otherwise the heap turns slimy. See our guide on how to make compost.

Saving seed

Save seed from open-pollinated flowers and veg. Let the seed heads ripen and dry on the plant, then collect them into paper envelopes. Label with the variety and date, and store somewhere cool and dry.

Month-by-month summer checklist

Common summer mistakes

Little sprinkles every evening

A quick sprinkle only wets the top of the soil. Roots stay shallow and plants need water every day. Water less often but much more deeply.

Letting courgettes turn into marrows

One courgette left for a week becomes a marrow. The plant then puts its energy into that one fruit instead of new ones. Keep picking.

Pruning lavender too late

Trimming lavender in late autumn leaves soft new growth that can be damaged over winter. Trim it straight after flowering, while there’s time for a little regrowth.

Keeping the greenhouse shut

Shutting the greenhouse to keep warmth in is fine in spring, but in summer it cooks plants. Very high heat stops tomatoes setting fruit and scorches leaves. Open everything up on warm days.

Mowing a brown lawn

A brown lawn is resting, not dead. Mowing it does damage. Leave it alone and it’ll green up once the rain comes.

Now your summer jobs are sorted, read our guide on autumn gardening jobs for what comes next.

Frequently asked questions

How often should I water my garden in summer?

Give beds a deep soak once or twice a week. That’s better than a light sprinkle every day. Water early in the morning or in the evening. New trees and shrubs need watering all through their first summer, even if it rains.

When should I deadhead flowers?

Every few days while plants are in full flower. Cut old blooms back to the first healthy leaves below. Roses, dahlias, sweet peas and bedding plants all flower for longer when deadheaded.

Should I mow the lawn in a heatwave?

Raise the blades and mow less often. Longer grass shades its roots and copes better with drought. Never mow a brown lawn. It’s resting, and it greens up again once the rain returns.

What vegetables can I still sow in summer?

French beans, beetroot, spring onions and lettuce until about mid-July. In August, sow turnips, spring cabbage and winter salad leaves. Quick salad leaves are ready in a few weeks, so a July sowing gives you an autumn crop.

How do I stop tomatoes splitting?

Water regularly and never let the compost dry out. After a dry spell, a sudden drink makes the fruit swell fast and the skin splits. Water daily in hot weather and feed with tomato feed once the fruit sets.

When should I prune lavender?

Straight after it flowers, usually late July or August. Cut off the flower stalks and a little of the leafy growth, shaping it into a dome. Never cut into old, bare wood, as lavender won’t grow back from it.