How to keep your border looking good for longer

Every gardener knows that weeding is the quickest way to make a border look tidy. Weeds will continue to appear all summer so keeping on top of them is vital. Weeding a little and often is the best way to keep them under control. As you walk past your border, pull out any obvious large weeds and any that are about to set seed. If you have more time, get in amongst your plants to clear weeds out before they get too established.

Cut back and tidy

Early summer perennials that have finished flowering can look untidy in a border. There are exceptions, like the Turkish sage, Phlomis russeliana, which has upright, structural stems, and some peonies have good autumn colour but many others just flop over, smothering surrounding plants. Cut them back after flowering, not to ground level but leaving a few leaves. Lupins, astrantias, Campanula lactiflora or geraniums like ‘Brookside’ and ‘Orion’, for example, will produce fresh leaves and sometimes, as a bonus, more flowers.

Fill gaps left by early perennials

Once you have cut back earlier flowering plants, you may be left with gaps in your border so take the opportunity to plant something new. You could try a late summer perennial like rudbeckia or an ornamental grass but remember the earlier flowering plant is still there and needs space. A better solution is to plant an annual that will keep flowering for the rest of summer. It is too late to grow from seed now but you can buy plants like cosmos or zinnia for long-lasting colour.

Provide support

Plants laden with late summer flowers can become top heavy, causing the stems to arch over or collapse completely. The best time put in plant supports is in spring so the stems can grow through and hide them but if you didn’t manage to do that, it is not too late to give plants some support now. Branched sticks pushed in the ground will hold up stems or you can use metal hoops to make a supportive fence around the plant.

Autumn bulbs

To provide late colour in the garden and brighten up a border, plant some autumn flowering bulbs or corms. There is less choice than in spring but there are some beautiful bulbs to plant now for autumn colour. Colchicums can flower in September so don’t delay planting them. Other autumn bulbs to plant now include Crocus speciosus, nerines and the yellow goblets of Sternbergia lutea. Their leaves grow in the winter and by next summer they have safely retreated underground.

Summer border problems, solved

Summer watering

A summer drought can wreck a border. To encourage plants to send roots deeper into the soil for moisture, only water when they start to look stressed. Water from a can at the base of the plant, early in the morning or late in the evening, to reduce water loss through evaporation.

• Garden guide to summer watering
• Dealing with drought in the garden

Powdery mildew

Some plants, like monarda and phlox, are susceptible to powdery mildew on their leaves, which can look unsightly. An open, airy position in full sun helps reduce its occurrence but it is rarely fatal so you can just hide the affected foliage by planting different, shorter plants in front.

Aphids

Aphids can smother new shoots, damage leaves and cause stunted growth. Be vigilant and remove any infested leaves and shoots as soon as possible, squashing the aphids between your fingers. This will help keep them under control but you may just have to tolerate some in your garden.

More summer border advice and inspiration

• The best plants for long-lasting summer colour
• How to add late summer colour to borders
• Six ways to get your borders ready for summer
• Plants for late summer colour
• Podcast: How to create a beautiful summer garden with West Dean Head Gardener, Tom Brown