What to Sow, Plant, and Do in July: Your Month-by-Month Guide for a British Garden

July arrives in the garden like a slightly overwhelming houseguest: full of energy, demanding your attention on multiple fronts, and utterly uninterested in being kept waiting. The beds that looked so orderly in June have filled in, cropped up, or run to seed, depending on how closely you have been watching. The courgettes have almost certainly done something you did not sanction. And somewhere in the kitchen garden, a row of spring-sown salad leaves is bolting in the heat with an enthusiasm that would be charming if it were not so inconvenient. This is the month that sorts the attentive gardener from the aspirational one, and it is worth approaching it with a clear plan.

Sowing Now for Autumn Abundance

One of the most important things to understand about July is that it is not too late to sow. It is, in fact, exactly the right time to sow a number of things that will carry you through to October and beyond, and the gardener who puts it off until August will find the window has quietly closed.

Spring onions sown now will be ready from September. Radishes take as little as four weeks, meaning you can squeeze in two or three sowings before the season turns. Spinach, which sulks when sown in the heat of May, does rather better with a July sowing into slightly cooler, moister soil, particularly if you can tuck the row somewhere with a little afternoon shade. Winter purslane and lamb's lettuce can go in from mid-July onwards and will provide genuine salad leaves through November without so much as a fleece to their name.

If you grow your own, French beans can be sown outdoors until around the middle of July in most parts of the UK, though gardeners in the north of England or Scotland may want to bring it forward by a fortnight. The key with late bean sowings is to choose a sheltered spot and be prepared to harvest promptly; they will not have the long season of an April-sown batch, but they will produce.

Successional salad leaf sowings remain the backbone of a productive kitchen garden through summer, and July is no time to stop. A short row every fortnight, in a shaded spot where the soil does not bake dry, will keep cut-and-come-again leaves on the table long after the first flush has bolted.

Planting Out and Maintaining Summer Crops

If you have been growing winter brassicas under cover, July is generally your last sensible window for planting out kale, sprouting broccoli, and winter cabbages. They need enough season to establish before the shortening days slow their growth, and a plant put in during the first two weeks of July will knit into the soil far more comfortably than one left sitting in a module tray until August.

Leeks that were sown in spring and have been growing on in a nursery bed can go into their final positions now. The traditional method of dropping them into a dibber hole and watering in without backfilling the soil works perfectly well, leaving the hole to gradually fill as the plant fattens. This is not superstition; it genuinely encourages the long blanched stems that make leeks worth growing.

For those still earthing up maincrop potatoes, July is usually the month that sees the job through. Keep the haulm well mounded to prevent any tubers near the surface turning green, and if blight has not found you yet, keep a watchful eye: warm nights and humid days create exactly the conditions it prefers. At the first sign of dark lesions on the foliage, remove the affected stems promptly and consider cutting the entire haulm down to soil level, which will not save the haulm but will give the tubers below a better chance of escaping infection.

Runner beans growing up supports need checking weekly now. They move quickly, and a stem that winds around a neighbouring cane rather than its own becomes a small structural problem within days. A little attention while the plant is still pliable saves a good deal of untangling later.

The Flower Garden in July

The herbaceous border is at or close to its peak, and the temptation is simply to stand and admire it. This is entirely reasonable, but there are one or two things that want doing alongside the admiring.

Hardy geraniums that flowered in May and June and now look tired and brown-edged are begging to be cut back. This is one of the most satisfying jobs in the summer garden: take a sharp pair of bypass secateurs and cut the whole clump down to a few inches above the ground. It looks brutal for approximately a week, and then fresh foliage begins to push through, followed in most years by a second flush of flowers in August and September. A handful of balanced fertiliser or a good mulch of garden compost worked in around the base at cutting time helps things along.

Sweet peas need picking and picking and picking. The one reliable rule with sweet peas is that any flower allowed to form a seed pod tells the plant its work is done, at which point it obliges by stopping. If you have more flowers than you can cut for the house, give them away, leave them on the doorstep, take them to neighbours. Just do not leave them on the plant.

Dahlias, if you grow them, will be building towards their first flowers now and benefit from a liquid feed every ten days or so. A high-potash feed rather than a nitrogen-heavy one will encourage flower production over leafy growth. Pinching out the leading shoot if you have not already done so will give you more stems and therefore more flowers, though by July it is not the end of the world if the moment has passed.

Cosmos, zinnias, and rudbeckia sown in spring are either flowering or on the cusp of it, and regular deadheading will keep them producing until the frosts. In my own garden, a well-deadheaded cosmos sown in April will still be throwing flowers in October, which is a remarkable return on a paper packet of seeds.

Lawn Care and the Art of Adjustment

July in a British garden does not always mean scorching heat, but when a dry spell does settle in, the lawn is usually the first thing to suffer. The temptation is to mow shorter, hoping to reduce water demand; in fact the opposite is true. Raising the cutting height during dry periods means the grass shades its own roots, retains moisture more effectively, and recovers far better when rain returns. Allow it to go slightly brown in a prolonged dry spell rather than stressing it further with close mowing. A lawn that has browned in summer heat almost always recovers once rain arrives; a lawn that has been scalped may take considerably longer.

If you are edging borders or around beds, keep a eye out for areas where summer growth has caused grass to push inward. A clean edge makes an enormous visual difference to a garden in full growth, where everything else is blowsy and exuberant.

Pest and Problem Management

Slugs do not take July off, particularly after rain. A garden that has been dry for a week and then receives a heavy shower will see slug activity spike almost immediately. Copper tape, nematodes, and regular evening patrols with a torch remain the practical tools here. Nematodes work best in moist, warm soil, making late July an effective time to apply them if you have not already done so this season.

Vine weevil is worth keeping in mind for anyone with plants in containers. The adult weevils, which are nocturnal, notch the leaf margins of a wide range of plants, including heucheras, begonias, and fuchsias. If you spot the characteristic scalloped damage, check the compost in suspect pots; the creamy grubs feeding on the roots do the real harm. Nematodes are again the practical organic control here, applied when the soil temperature is reliably above 5 degrees C, which it certainly will be in July.

Powdery mildew tends to appear on courgettes, squash, and certain roses from midsummer onwards, particularly in seasons where there is a temperature contrast between warm days and cool nights. Keeping plants well watered at the roots (rather than overhead) and ensuring reasonable airflow around them is the most effective preventive measure. Once mildew takes hold, remove affected leaves and dispose of them rather than composting.

What to Consider Before the Month is Out

If you have been meaning to feed your container plants, do it now. Containers exhaust their compost nutrients far faster than border plants, and a plant that looks merely tired in July is often genuinely hungry. A fortnightly liquid feed, either a balanced general fertiliser or a high-potash one if you want to encourage flowering, makes a visible difference within a fortnight.

For kitchen gardeners, this is a good moment to review what has worked and what has not. The varieties you could not keep up with, the bed that dried out too fast, the crop that bolted before you could use it: note it all down somewhere while it is fresh. The RHS keeps comprehensive records of Award of Garden Merit vegetables, and reviewing the list in winter with your own notes to hand is a genuinely useful way to make better choices for next year.

There is plenty to do in July, and most of it cannot wait. Start with whatever is most urgent: support that needs going in, seedlings that need pricking out, flowers that need cutting. The rest will follow.