Bring lasting colour to your garden this August
By August, some early-summer flowers are beginning to fade, but a well-planted border can still provide plenty of colour and interest. Late-flowering perennials and compact shrubs can also supply valuable nectar and pollen when fewer plants are in bloom.
The five plants below are dependable choices for extending the season. Each has different requirements, so consider the amount of sun, soil drainage and available space before planting.
For more seasonal maintenance advice, see my guide to August garden jobs.
1. Rudbeckia (Black-Eyed Susan)
Rudbeckias produce bright yellow, daisy-like flowers from late summer into autumn, making them useful for filling gaps as earlier flowers begin to fade. Their open flower heads also attract bees and other pollinating insects.
Most perennial rudbeckias grow best in full sun and reasonably fertile soil that does not remain waterlogged. They can cope with some dry weather once established, although newly planted specimens will need regular watering during prolonged dry spells.
Variety to consider: Rudbeckia fulgida var. sullivantii ‘Goldsturm’ is a dependable perennial variety with golden-yellow flowers and dark central cones. It works well through the middle of a sunny border and usually reaches around 60 centimetres tall.
2. Hylotelephium (Formerly Sedum)
Often still sold under the familiar name sedum, hylotelephiums are reliable late-flowering perennials with fleshy leaves and broad clusters of pink, red or bronze-toned flowers. Their sturdy flower heads provide useful structure in a border and are particularly valuable to bees and other pollinators in late summer and autumn.
Plant them in a sunny position with well-drained soil. Once established, they cope well with relatively dry conditions, making them a useful choice for warm borders and gravel gardens. Avoid wet or heavily shaded positions, where the stems may become weak or the roots may rot.
Leave the dried flower heads standing over winter for structure and shelter for insects, then cut the old stems back close to ground level in early spring.
Variety to consider: Hylotelephium ‘Herbstfreude’, commonly sold as ‘Autumn Joy’, develops large flower heads that gradually deepen from pale pink to coppery red.
3. Crocosmia
Crocosmia produces arching stems of red, orange or yellow flowers from mid to late summer. Its upright leaves and vivid flowers add height and movement to a border, while the blooms attract bees and other pollinating insects.
Plant crocosmia in sun or light shade, in soil that retains some moisture but drains well. It can cope with occasional dry spells once established, although flowering may suffer during prolonged drought. In exposed or colder gardens, adding a layer of mulch in autumn can help protect the corms.
Some varieties spread readily, so divide overcrowded clumps in spring if flowering begins to decline or the plant starts to take over nearby space.
Variety to consider: Crocosmia ‘Lucifer’ has strong red flowers and can reach around 1.2 metres tall, making it best suited to the middle or back of a border.
4. Echinacea
Echinaceas produce bold, daisy-like flowers in shades of pink, purple and white from midsummer into early autumn. Their prominent central cones add strong structure to a border, while the flowers attract bees, butterflies and other pollinating insects.
Plant them in full sun and well-drained soil. They tend to perform poorly in heavy, wet ground, particularly over winter, so good drainage is important. Newly planted echinaceas need regular watering while they establish, but mature plants can cope with short dry periods.
Leave the seed heads standing through autumn and winter. They provide seasonal structure and may be used by seed-eating birds before the old stems are cut back in spring.
Variety to consider: Echinacea purpurea is a dependable choice for sunny borders, with pink-purple petals surrounding a raised orange-brown cone.
5. Caryopteris
Caryopteris is a compact, late-flowering shrub with clusters of blue flowers that appear from late summer into early autumn. It is particularly useful for adding colour after many summer perennials have started to fade, and its flowers are attractive to bees and other pollinating insects.
Plant it in a warm, sunny and sheltered position with well-drained soil. Caryopteris copes well with dry conditions once established, but it dislikes cold, wet ground and may struggle in exposed sites.
Prune it in spring, once the risk of severe frost has passed, cutting back the previous year’s growth to encourage fresh shoots and a good display of flowers.
Variety to consider: Caryopteris × clandonensis ‘Heavenly Blue’ is a compact choice with deep blue flowers and grey-green foliage.
Bonus Choices for Containers or Partial Shade
Not every garden has a large, sunny border. These plants can provide useful late-summer interest in containers or areas that receive some shade:
- Heuchera – grown mainly for its colourful foliage, with varieties ranging from lime green to bronze, purple and almost black. It performs well in containers and partial shade, although very dry soil can cause the leaves to scorch.
- Hardy fuchsia – produces long-lasting flowers from summer into autumn and generally performs well in sun or partial shade. Check that the variety is hardy before planting it permanently outdoors, as many container fuchsias need frost protection.
- Japanese anemone – provides pink or white flowers from late summer into autumn and tolerates partial shade. Give it room to spread, as an established clump can gradually move into neighbouring areas of the border.
Can You Plant in August?
Container-grown perennials and shrubs can be planted in August, but hot, dry weather can make establishment difficult. During prolonged heat or drought, it is often better to wait until conditions are cooler and the soil has regained some moisture.
When planting cannot be delayed, water the plant thoroughly before removing it from its pot, prepare a wide planting hole and water it in well afterwards. Continue checking the soil regularly rather than relying on light surface watering. A layer of mulch can help conserve moisture, but keep it clear of the plant’s crown and stems.
Avoid planting into baked, bone-dry soil unless it can be watered deeply and consistently during the following weeks.
Further Reading
Need Help Refreshing Your Borders?
I can help with clearing tired planting areas, preparing beds, planting suitable shrubs and perennials, mulching and carrying out ongoing border maintenance.
For larger planting projects, I can also help source plants based on the conditions in your garden and the amount of maintenance you want. Every garden is different, so I will always consider factors such as sunlight, drainage, available space and access before recommending an approach.
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