Here's a few ideas of what you could be doing this month...
Top Tip - Get fruity
It’s easy to make more strawberries by potting up rooted baby plants (known as runners). Severe the stem between the runner and mother plant, then prise it carefully from the soil with a hand fork. Remove any dead leaves and pot into a small container filled with compost.
Grab your secateurs and give cordon, espalier and fan trained apple and pear trees a summer prune. Start by looking for this season shoots and cut any that are 20cm long and growing from a side branch, back to one leaf. Any new shoots growing from a main branch should be reduced to three leaves.
Order new trees, bushes and cane fruit for planting in the autumn.
Reduce the risk of brown rot fungal disease spreading to healthy apples and plums on the trees by removing any fruit that have rings of white spores or soft brown patches on the outer skin. Put in the wheelie bin, not on the compost heap.
Beds and borders
• Help border plants survive dry periods by covering bare areas of soil with a thick layer of mulch. A 10cm thick carpet of garden compost, leafmould or well-rotted manure will lock in moisture for longer. Water the soil first or apply after rain.
• Control leaf disfiguring powdery mildew on michaelmas daisies by spraying with a copper-based fungicide, such as Bordeaux Mixture. Repeat the treatment in two weeks.
• Rejuvenate large clumps of bearded iris. After a few years the centre of clumps can die off and plants will be reluctant to flower. To restore vigour, prise from the ground with a fork and divide up the outer sections of the plant with a knife. Cut straight across the leaves, 15cm from the roots, and replant 15cm apart.
• Support top heavy, late-flowering perennials to prevent them toppling over in a sudden downpour or gust of wind. Place four stout canes around dahlias, asters and helianthus, then tie a length of twine to a cane and enclose all the stems by wrapping it around the rest of the canes. To ensure plants don’t flop, keep the twine tight.
• For delicate splashes of colour during September and October, plant colchicums in borders now. These sophisticated bulbs, also known as autumn crocus, have funnel-shaped flowers in white and many shades of pink. Plant 10cm deep, in a sunny spot.
Trees and shrubs
• Trim evergreen hedges so they look good over winter. During summer, box, privet, laurel and other hedging plants will have put on lots of growth, turning a crisp outline into a shaggy eyesore. Use a pair of hand shears or a powered hedge trimmer, start by cutting the top of hedge flat and then trim the sides, ensuring that the top is narrower than the base.
• Trim lavenders lightly when blooms start to fade, aiming to remove the spent flower heads. Prune harder in early spring, aiming to remove about 5cm of growth.
• Large flowered clematis are now in full flight, but are particularly prone to clematis wilt disease. Avoid problems by planting new clematis deeply – 10cm below the level it was in its pot is ideal.
• If left to its own devices wisteria will outgrow its allotted space and flower poorly. First, tie in any stems to fill any gaps on walls or trellis, then ensure a great floral display next year by cutting back all of the whippy shoots produced during the current season to five to six leaves - this will encourage buds to form.
In the kitchen garden
• For the best greenhouse cucumbers, pinch out the leader, or uppermost shoot, when it reaches the top of the structure and shorten side shoots, leaving two leaves beyond each developing fruit.
• Speed up ripening of squash plants by removing any large leaves that shade the developing crop from the sun.
• Lift onions from the soil when leaves have withered and turned a straw-brown colour. If the weather is good leave them on the soil for a couple of weeks to dry, or bring indoors if raining. Store in wooden fruit boxes.
• A black, flat hard patch on the bottom of tomatoes is a sign of blossom end rot, a common problem caused by lack of calcium, which is found in water. Avoid damage to your fruit by watering daily, or even twice a day during hot weather.
• Sow overwintering salad onions, Japanese onions, spring cabbage, turnips and carrots in vegetable gardens.
• Ensure courgettes remain productive by picking young fruit regularly. Harvest when they are about 10cm long to encourage more to grow and to prevent them turning tough and woody.
• For a crop of spinach to pick at the end of September, sow seeds of ‘Scenic’, ‘Toscane’ or ‘Tornado’, 2.5cm deep in rows and thin to 7.5cm apart after they’ve germinated.
• Ensure you have a fresh supply of parsley over winter by sowing seeds now. Fill a shallow, 20cm pot with compost and sow thinly over the surface. Cover with a 1cm layer of compost, water and put in a coldframe of sheltered spot. Seedlings will appear within a month, and you’ll be able to pick leaves from December through to next summer.
• Compost heaps can stop working in hot, dry weather, so ensure all of your spent garden waste continues to rot by occasional watering heaps and turning with a fork. If it doesn’t have a lid, place a sheet of cardboard or a piece of old carpet on top to retain moisture and heat.
• A spell of hot weather can dry up bird baths, so top them up regularly to ensure there is always a fresh supply of water.
• As the evenings start to get cooler, close greenhouse vents, doors and windows at night to lock in warmth. Remember to open again in the morning to avoid the build up of excessive temperatures during the day.
• Keep an eye out for craneflies (daddy longlegs) skipping across the lawn. Their larvae, known as leatherjackets, nibble the roots of grass causing unsightly brown patches to develop. Control by watering your sward with Nemasys Leatherjacket Killer (available from garden centres).