Essential gardening jobs
Hoe borders regularly to keep down weeds.
Be water-wise, especially in drought-affected areas. Only water what is in desperate need. It may seem cruel, but plants will develop deeper more sustainable roots this way.
Pinch out sideshoots on tomatoes, to encourage fruiting. Sideshoots easily root in water.
Harvest lettuce, radish, other salads, and early potatoes.
Feed summer containers.
Mow lawn once a week (consider leaving some areas uncut for wildlife).
Deadhead and feed annuals to extend the flowering period.
Net fruit bushes.
Shade greenhouses to keep them cool and prevent scorch.
Mow regularly, except during drought. In hot weather, set the mower at a slightly higher level than normal for early summer. This can prevent the lawn drying in hot weather and keep the grass greener for longer.
This is also the last time to apply a liquid summer lawn fertiliser, especially if a spring feed was not given. A soluble feed and weed product may be useful if there are weeds present in the lawn.
Don’t worry unduly about brown patches on the lawn - they will recover quickly when the autumn rains arrive.
If a completely green lawn is necessary, then use a sprinkler once a week. Place an open jam-jar on the lawn and leave the sprinkler running for sufficient time for 13mm (0.5in) of water to collect in the bottom of the jar. This is the optimum amount to avoid wasting water, while still wetting the roots sufficiently.
New areas of grass, sown or turfed in the spring, will need extra watering to keep them going through their first summer.
Lawn growth slows down in late summer. Raise the cutting height slightly as the month progresses, to help the grass better resist the wear it suffers in summer.
Inspect any yellow patches on the lawn: if they contain small pinkish-red strands, then you may have red-thread in the lawn. This is a fungal disease, common on light soils after heavy rain, when the nitrogen is washed out of the soil. A nitrogen-rich fertiliser should remedy the situation, and the damage is rarely long-lived.
By mid-summer, some lawns may be heavily infested by ants. Brushing out the nests on a dry day is the best method of control and should be done prior to mowing.
Trees & shrubs
Prune June-flowering shrubs such as Philadelphus and Weigela after flowering. Prune deciduous magnolias if necessary.
Fast-growing hedges such as Leyland cypress should be clipped as necessary throughout the growing season.
Tie-in climbers and ramblers as they grow. If you tie in as close to an arch shape as possible you will encourage flower and bud production. Tying in horizontally will encourage stem growth.
Take semi-ripe cuttings of shrubs such as Choisya, Hydrangea and Philadelphus. Root them in pots of gritty compost in a cold frame or even with a plastic bag tied over them.
Clematis can be propagated by taking internodal cuttings (i.e. taking stem sections above and below a leaf, rather than cutting the stem immediately below a leaf joint).
Air-layering is another method of propagation that can be used for some climbers, such as Akebia, and some shrubs, such as magnolia.
Brown patches on conifers may indicate an earlier infestation by the cypress aphids. Tell-tale signs include black sooty mould along the stems and shed skin cases. Spraying earlier in the summer may have helped, but once damage is done, conifers can take a long time to recover. Where hedges are affected prune out brown shoots and tie in neighbouring branches to help fill the gaps.
Thickened and curled margins on bay trees (Laurus nobilis) are a sign of damage by the bay sucker. Scale insects can also affect bays at this time of year.
Neat circular areas removed from the edges of rose and other leaves are tell-tale signs of leaf-cutter bees at work. These fascinating creatures are best tolerated since damage is rarely severe.
Yellow and distorted leaves on cherry laurel (Prunus laurocerasus) indicate a powdery mildew problem.
You may notice damage on leaves of Viburnum by Viburnum beetles. The damage is not usually bad enough to warrant treatment.
Keep an eye on stalking and tie-in tall plants exposed to mid-summer breezes.
Mulch perennials with (seedless) grass clippings to retain soil moisture.
Unless the seed head is attractive, or wanted, deadhead perennials to ensure energy is used for root growth development.