By August, many gardens start to look quite different from the colourful displays they had at the beginning of summer.
Early-flowering plants may be going over, some bedding plants can begin to look tired and gaps that weren’t obvious in June suddenly become much easier to see.
The good news is that you don't start again.
Choosing a few plants that naturally perform later in the season can bring fresh colour and structure back into borders, pots and patio displays, while also helping the garden make a smoother transition from summer into autumn.
There are plenty of perennials, grasses and flowering plants that can still be providing interest during August and September. The important part is choosing plants that suit the conditions in your garden rather than simply picking whatever happens to be flowering at the time.
Can you plant perennials in August?
You can plant container-grown perennials during summer, although they will need more attention while they establish.
During summer, newly planted perennials need to be kept well watered because warmer weather and dry soil can cause them to lose moisture quickly.
If conditions are particularly hot or dry, avoid planting during the hottest part of the day. Plant in the morning or later in the day where possible, water the plant thoroughly and continue checking the soil while the roots establish.
It is also worth remembering that August planting doesn’t need to involve redesigning an entire border.
One or two carefully chosen plants can often be enough to fill an obvious gap, add height where a display has become flat or introduce another period of flowering as earlier plants begin to finish.
Which plants give good colour in late summer?
Echinacea
Echinacea is a popular perennial for sunny borders, producing distinctive daisy-like flowers during summer and often continuing well into the later part of the season.
They work particularly well alongside grasses and other flowering perennials, where their upright stems can add both colour and structure.
Echinacea prefers a sunny position and well-drained soil, so it is better suited to an open border than a consistently wet or heavily shaded part of the garden.
The prominent flower centres also give the plant plenty of character even as individual flowers begin to mature.
Rudbeckia
If you want stronger yellow and golden tones later in the summer, rudbeckia is worth considering.
Its bright flowers can provide a useful contrast against darker foliage, ornamental grasses and purple or blue flowering plants.
Rudbeckias perform best in sun and can be particularly effective when planted in groups rather than as a single isolated plant.
Their seed heads can also provide interest later in the year and leaving the seed heads of plants such as rudbeckia can provide food for birds.
Salvia
Salvias are extremely useful for extending colour through summer.
Depending on the type, they can produce upright spikes of blue, purple, pink, red or white flowers and work well in both borders and containers.
Many salvias perform best in a sunny, sheltered position with free-draining soil.
Their vertical flower spikes also make them useful when a planting scheme needs shape rather than simply more colour at ground level.
Hylotelephium, often sold as sedum
Hylotelephium provides something slightly different later in the season.
Its broad flower heads develop as summer progresses and can work particularly well alongside grasses, echinacea and other later-flowering perennials.
It prefers a sunny position and well-drained soil and is a useful choice where you want a plant that will contribute shape as well as flowers.
Leaving the flower heads in place after flowering can also provide attractive structure through autumn and winter.
Japanese anemones
For a softer late-summer display, Japanese anemones can be particularly useful.
Their flowers are held on tall stems above the foliage, making them effective towards the middle or back of borders.
They are also useful because they can cope with conditions where some sun-loving late-summer perennials may struggle, including areas with partial shade.
Give them enough room to establish and they can become an important source of late-season colour year after year.
Crocosmia
Crocosmia brings warmer shades of orange, red and yellow into the garden and can add strong vertical movement to a border.
The arching stems and sword-shaped leaves give the plant plenty of presence even before the flowers fully open.
Crocosmia works particularly well when combined with contrasting purple flowers, grasses or darker foliage.
It prefers sun or light shade and soil that doesn’t become excessively dry.
Dahlias
Few plants provide quite as much impact in late summer as dahlias.
Their range of flower colours, shapes and sizes makes them useful in everything from mixed borders to large patio containers.
Regular deadheading can encourage dahlias to continue flowering for longer. Deadheading dahlias during August to help prolong displays into early autumn.
Keep an eye on watering too, particularly where dahlias are growing in containers.
Penstemons
Penstemons can be another good option where you want flowers to continue beyond the main early-summer period.
Their upright flower stems bring height without creating the visual weight of a large shrub, which makes them particularly useful for filling gaps between established plants.
They tend to prefer sun or light shade and reasonably well-drained soil.
Regularly removing faded flowers can also help prolong their display.
Ornamental grasses
Late-summer colour doesn’t have to come entirely from flowers.
Ornamental grasses begin to play a much bigger role as the season develops, bringing movement, height and texture to borders.
Their seed heads can look particularly effective when mixed with flowering perennials and can continue adding structure long after many flowers have finished.
Avoid cutting the flower heads from ornamental grasses once summer ends.
What are good late-summer plants for sunny borders?
Sunny borders give you plenty of options.
Plants such as echinacea, rudbeckia, many salvias, hylotelephium, crocosmia and ornamental grasses can all contribute to a strong late-summer display when their individual growing requirements are suitable.
Rather than filling every gap with the same type of flower, think about the overall shape of the border.
Combine upright flowers with lower-growing plants and grasses, then repeat some colours through the planting rather than using a completely different colour in every space.
This creates a more coherent display and can help an established border look refreshed without requiring a complete redesign.
What can you plant for late-summer colour in pots?
Containers can start to lose their impact surprisingly quickly during August, especially after periods of warm weather.
Perennials and grasses can offer an alternative to replacing an entire display with more bedding.
Compact salvias, smaller ornamental grasses, suitable echinacea varieties and other container-friendly perennials can all work well, provided the eventual size of the plant matches the pot.
The biggest issue with containers during August is often water.
Pots dry out much faster than open ground, particularly on sunny patios. Give container-grown perennials regular water throughout the growing season and pay particular attention during hot weather.
Make sure the pot has adequate drainage and check the compost rather than relying on how the surface looks.
What can you plant for colour in partial shade?
A border that doesn’t receive full sun still has options.
Japanese anemones are particularly useful later in the season, while some hardy geraniums, heucheras and other shade-tolerant perennials can provide a mixture of foliage and flowers.
The key is to distinguish between partial shade and deep shade.
An area that receives several hours of morning or evening sun gives you considerably more choice than a permanently dark space beneath dense trees or beside a north-facing wall.
When choosing any perennial, check its preferred position and soil conditions first. Perennials are available for a wide range of situations, but choosing a plant suited to the location is fundamental to getting good results.
Don't forget foliage and structure
It is easy to focus entirely on flowers when trying to brighten a tired August garden.
Colourful foliage, grasses, shrubs and plants with strong architectural shapes can be just as important.
Heucheras, for example, are grown as much for their foliage as their flowers and can introduce bronze, lime, purple and darker tones without relying on a constant succession of blooms.
Grasses create movement.
Shrubs provide the permanent framework.
Flowering perennials can then sit between them rather than carrying the entire display by themselves.
This becomes increasingly useful as the garden moves towards autumn.
How to keep your garden flowering for longer in August
A few simple jobs can help existing displays continue for considerably longer.
Remove faded flowers from repeat-flowering plants where appropriate, particularly bedding, dahlias, roses and penstemons. Deadheading prevents some plants from putting their energy into seed production and can encourage further flowering.
Keep containers watered consistently and pay particular attention to anything newly planted.
Hanging baskets also still need attention. Regular watering, feeding and deadheading can help them continue performing into autumn rather than being written off as soon as August arrives.
However, don't automatically remove every seed head in the garden. Some provide winter structure or a source of food for wildlife, so it is worth being selective about what you tidy away.
Think beyond August
One of the advantages of choosing perennials rather than treating every gap as a short-term problem is that you can improve the garden for future years at the same time.
Look at where colour disappears first.
Notice which parts of the border lack height.
Think about where grasses, foliage plants or later-flowering perennials might provide something that the garden currently lacks.
August is actually a useful time to identify these weaknesses because you can see exactly what the garden looks like after its earlier displays have finished.
Adding the right plant in the right place can make a surprisingly big difference.
Looking for late-summer plants near Preston?
If your borders or containers are beginning to look tired, visiting a nursery while plants are actively growing can make choosing replacements much easier.
You can compare flower colours, foliage, height and overall shape rather than trying to imagine how a plant will look from a label alone.
At Old Oak Farm Nurseries, you can browse the plants currently available and ask for advice based on the conditions in your own garden, whether you are looking for something for a sunny border, a partially shaded area, a patio container or simply an awkward gap that needs filling.
Frequently asked questions
What flowers in August in the UK?
Many garden plants can still be flowering strongly during August, including dahlias, salvias, echinacea, rudbeckia, penstemons, Japanese anemones and crocosmia, depending on the variety, growing conditions and part of the UK.
What perennials flower in August and September?
Late-flowering perennials can include echinacea, rudbeckia, Japanese anemones, hylotelephium, some salvias and penstemons. Flowering times vary with the variety, weather and location, so use the plant label as the guide for the specific plant you are considering.
Can I plant perennials in August?
Container-grown perennials can be planted during August provided the soil conditions are suitable, but they need careful watering while they establish. Spring and autumn generally provide easier planting conditions because the soil is cooler and naturally holds more moisture.
Which plants are best for late-summer pots?
The right choice depends on the size and position of the container. Compact salvias, ornamental grasses, smaller perennial varieties and other plants suited to container growing can provide colour and structure beyond the peak of summer. Always check the eventual size and preferred growing conditions before planting.
Should I deadhead flowers in August?
Many flowering plants benefit from having faded blooms removed, particularly repeat-flowering plants. However, some seed heads are worth leaving for wildlife or winter interest, so avoid treating deadheading as a job that needs doing to every plant in the garden.
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