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Home & garden.

16 August 2021

Gardening jobs for July

Our experts suggest cutting back early-flowering perennials, harvesting veg and feeding the lawn in July.
CT
Ceri Thomas
Flower border

July sees the garden full of flowers and looking at its best. There's plenty to do to keep the display going and to enjoy great crops, including harvesting veg at its peak and feeding the lawn. Let the Which? Gardening experts help you.


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Gardening maintenance for July

Feed your lawn

For many of us the lawn is the centrepiece to the garden that sets off everything else. 

  • As long as there is no drought, it's worth feeding the lawn regularly - try our Best Buy lawn feed.
  • During dry weather, raise the blades on your lawn mower to allow the grass to grow a little bit longer. This will keep it greener and help it retain moisture.
  • Don't panic if your grass does turn brown as it will soon green up again when the rain returns.

Try a Best Buy lawn feed

Keep your pond in top condition

Ponds and other water features also need some care in July and August to keep them healthy and looking good.

  • Look out for any yellowing leaves If they are left on water lilies and other water plants, remove them promptly. Allowing them to fall off and rot in the water will decrease water quality.
  • Remove blanket weed This will let oxygen into your pond. Use a net or rake and remember to give aquatic life a chance to get back to the water by piling the weed next to the pond for a day.
  • Top up water levels. Water can evaporate rapidly from water features and ponds in the height of summer, so top them up if the water level drops significantly. Rainwater from a water butt is best – chemicals in tap water can affect the nutrient balance in the pond. 
  • Hosepipe ban. If your area is under a hosepipe ban, you can still use it to top up your pond if you have fish.
  • Clear filters. Remember to clean any filters and pumps.

Water anything recently planted

Anything you’ve planted in the past few months will need regular watering while it puts out roots into the surrounding soil and establishes itself. Make sure that you give these plants a thorough soaking rather than a gentle sprinkle.

Discover our Best Buy garden hoses

Shade the greenhouse

If your greenhouse is in a sunny spot, it can quickly get too hot on sunny days. Put shading material or paint with shading paint to reduce the temperature inside.

Find out how to buy the best greenhouse

Make compost

Try to maintain a green/brown balance in the compost heap. Green materials are soft, high in nitrogen and not necessarily green in colour, for example coffee grounds, veg peelings and leafy prunings. Brown materials are often drier, more fibrous and with a higher carbon content, for example, twigs, cardboard and wood (but not coal) ash. In the summer, most ingredients are green, which results in compost heaps with a lack of structure and air being squeezed out, so it’s important to add an equal proportion of brown ingredients.

Discover our Best Buy compost bins

Grow-your-own-veg jobs for July

Keep sowing veg

There are lots of veg that can be sown now to fill gaps as earlier crops are cleared and to give fresh veg into the autumn and winter.

  • Sow kohlrabi, lettuce, leaf beet, chard, endive, chicory, Florence fennel, chervil and coriander. 
  • Finish sowing beetroot and savoy cabbage in the first week of July. 
  • After mid-July, sow land cress, Chinese cabbage and spinach. 
  • From the end of July to mid-August, sow mustards, pak choi and salad rocket.

Use a Best Buy compost for sowing seeds

Water veg as needed

Different types of veg need different ways of watering.

  • Leafy veg, such as lettuce, chard, kale, spinach, and herbs, such as coriander and basil, need most water to keep growing new leaves.
  • For fruiting veg, such as tomatoes, runner beans and courgettes, wait until flowering before watering, unless conditions are very dry before then.
  • Root veg, such as kohlrabi, beetroot and potatoes in their last month of growth, need little water other than when roots do a final swell. Every few days is better than a large dose weekly, which might cause splitting of roots.
  • For plants under cover, water every three or four days in summer, giving plenty each time. Water the soil or compost surface only, keeping leaves dry to reduce opportunities for late blight on tomatoes.
  • Reduce watering in early autumn for tomatoes in soil, to encourage fruit ripening. 
  • Water seed drills before sowing so moisture is in the drill not on top. After sowing, cover with dry soil as this reduces evaporation and keeps moisture near the seeds.
  • In dry weather, new plantings need water every two or three days until established. After a week or so, watering is only needed if the weather is very hot.

Lift onions

In about the middle of July, watch for when about two thirds of onion tops are falling over, then push the rest down to soften the neck as sometimes they can develop a long stem and a neck that doesn’t dry very well. You don’t need to wait until the tops go yellow before lifting, but you’re looking for the bulbs to begin to change colour. 

Pull them up and put them in a crate without being crowded so that air can circulate around them. Put it somewhere undercover such as in the greenhouse or garage. 

Allowing them to dry like this is important as they will store better. Done this way they should keep until spring. 

After they’ve dried in the crates for about a month, they’ll be ready to bunch up and hang in the house or in net bags until you need them.

Discover our Best Buy onions

Plants-and-flowers jobs for July

Encourage late-summer flowers

Now we're in July, some plants are just past their peak.

  • Cut back early flowering perennials to the ground and they will send up fresh leaves and maybe even the bonus of some extra late-summer flowers. 
  • Give them a boost after pruning with a good soak of water and some tomato feed.
  • Exploit plants' desperate need to set seed by removing blooms as they fade. This will encourage them to produce more flowers to replace them. 
  • Remember that plants in containers are dependent on you for their water as they'll get little benefit from any rain. Give them a good soak at least once a day in sunny weather.

Feed roses

Give roses a boost as the first flush of flowers fades by feeding them with arose food. Gently hoe it into the soil around the plant and water in.

Learn how to grow roses

Stake perennials

Stop tall perennials falling over in the wind by staking them. Put a cane in at the back, tie the string to it then loop it around the outer stems of the plant before returning to the cane and tying it in.

Watch out for lily beetles

Lily beetles are at their peak in July as many new adults emerge. Watch out for the red adult beetles and the black grubs, both of which will eat your lily leaves and flowers. Our trial found that removing lily beetles by hand is just as good as using our Best Buy chemical control, Westland Resolva Bug Killer.

Read more about lily beetle.