Astilbes are invaluable for adding colour and texture to shady, damp parts of your garden. Their feathery plumes of pink, red or white flowers bloom in summer above interesting green or bronze foliage. Leave the flowerheads on the plant for autumn interest.
Astilbes (false goat's beard) are herbaceous perennials that thrive in boggy, shady areas. While plenty of plants grow well in these conditions, few can match the spectacular blooms astilbes produce during the summer months. Whether you want to enjoy the vibrant flowers in your garden or a vase, these shade-loving plants should be top of your list – if you have the right conditions in your garden.
Astilbes are easy to care for and very hardy. They thrive in damp, cool parts of the UK, but if your soil is dry and your garden is a sun trap, they're unlikely to grow well. Astilbes bloom at different times throughout the summer, so if you have space, it's worth combining different varieties to enjoy their unique flowers over a longer period.
Where to plant astilbe
Astilbes need fertile, moist soil. They love the permanently damp soil found in bog gardens and around the edges of streams and ponds, but they'll struggle in waterlogged conditions, such as compacted clay soil. Astilbes prefer to be in the ground, but you can grow smaller cultivars in pots, as long as you keep them well watered.
Light or dappled shade is ideal, but astilbes can tolerate sun as long as the soil remains moist. Try to avoid locations where they'll get full afternoon sun, as this is likely to scorch the foliage in summer. Astilbes will grow in full shade, but you won't get as many flowers.
Astilbe plants vary in size, so choose a variety that suits your planting spot. Compact cultivars are useful for pots and to edge garden beds, while larger varieties are brilliant for woodland gardens and large, shady borders. If you have enough space, planting different varieties of astilbe plants together creates a flamboyant summer display.
When to plant astilbe
Plant astilbes during spring or autumn, when the soil is warm and moist. You can also plant them in summer, as long as the soil remains consistently moist.
How to plant astilbe
Astilbes are hungry plants, so it's worth working some manure or compost into the soil before planting. This will also help improve drainage on clay soils that are susceptible to waterlogging. Dig a hole a little larger than the rootball of the plant.
Remove your astilbe plant from its pot and gently tease out the roots. Place the plant in the hole, backfill the soil and firm it gently. Give the plant plenty of water, even if the soil is already damp, and add a thick layer of mulch. If you're planting lots of astilbes, check the eventual height and spread of each variety to make sure you give each plant the space it needs.
If you want to grow astilbe in pots, choose a dwarf cultivar and plant it in a large container at least 30 cm in diameter. Make sure the pot has drainage holes and fill it with a good-quality peat-free compost for containers, mixed with some well-rotted leaf mould.
Astilbe plant care
Astilbes need very little care if planted in the right conditions. If the soil doesn't naturally remain damp, then you'll need to water plants during dry spells to prevent the soil from drying out. Mulching regularly can help the soil retain moisture. You shouldn't need to feed astilbes.
If you're growing astilbes in pots, you'll need to water them frequently, even if it rains, as the foliage can often prevent water from reaching the compost. Apply a slow-release fertiliser in spring or use a diluted liquid fertiliser every few weeks from spring to late summer.
After your astilbe has finished flowering, you can either leave the flowerheads on to give architectural interest during autumn or remove them if you prefer a neater appearance. The foliage naturally dies back over winter. Cut back flowerheads and foliage in late winter, before new shoots emerge in spring.
Astilbes are fully hardy and don't require any winter protection. Mature plants form large clumps, which can die out in the middle as they age. Lift and divide these clumps every three or four years to keep the plants healthy.
How to propagate astilbe
The best way to increase your collection of astilbes is to divide large plants. Dig up the entire clump in early spring or autumn, just after the plant has finished flowering. Divide it into sections, making sure each section has shoots and roots. Either replant your new plants immediately or pot them up, so they don't dry out.
You can grow astilbe from seed, but it takes around three years for these plants to flower. Plants grown from seed you've collected will probably be hybrids, whereas plants you propagate by division will be replicas of the parent plant.
If you leave the flowerheads on your plants, you may find baby astilbe plants in your border the following spring. You can either leave them to grow where they are or dig them up and move them to your preferred location.
Common problems
Astilbes are easy to grow if given the right conditions. Plants that wilt or fail to bloom are most likely suffering from a lack of water. Unless your garden is a bog, astilbes need regular, deep watering, especially during warm, dry summers. While astilbes are woodland plants, tree canopies can prevent rainwater from reaching the soil and roots from competing plants will also remove water from the ground, so you may need to water your plants more than you think.
Intense sun can cause scorched leaves and may put plants under stress, which can affect flowering. If your astilbe plant seems to be struggling in a sunny spot, try moving it to somewhere shadier to see if that helps.
Astilbes may be affected by powdery mildew, a fungal disease that thrives in warm, humid environments. You can help prevent this by spacing plants according to their mature size, so they don't get overcrowded. If you spot powdery mildew, remove affected leaves immediately.
Most pests leave astilbes along, but they can be attacked by vine weevil grubs. The most effective treatment is to apply nematodes. Keep an eye on your plants for the telltale notches in leaves, so you can catch them early.
Our favourite varieties of astilbe
Astilbe 'Black Pearls' produces large, dense plumes of vibrant purple flowers that tower above the dark green foliage. A striking cultivar for late summer colour.
Astilbe 'Chocolate Shogun' has dark chocolate-bronze foliage, which contrasts beautifully with the airy, pale-pink flowerheads in mid to late summer.
As its name suggests, Astilbe 'Short 'n' Sweet Fireberry' is a compact cultivar that grows to around 40 cm tall. Plant it in pots or at the front of a border where its vibrant reddish-pink flowers will stand out.
Astilbe 'Wonderful Day' blooms earlier than many astilbes, from June onwards. It produces masses of rosy pink flowers above glossy, mid-green foliage.
FAQ
When do astilbes flower?
July and August are the peak flowering period for astilbes, though different cultivars flower at different times from late spring to late summer. Early-flowering varieties include Astilbe 'Europa' and Astilbe 'Deutschland'. There are plenty of options for mid-season colour, including Astilbe 'Black Pearls' and the Astilbe 'Short 'n' Sweet' series, while Astilbe 'Superba' is a late-flowering variety to give you a final burst of colour at the end of summer.
Are astilbe perennial?
Astilbes are herbaceous perennials. Their flowers and foliage die back in the autumn, and the plants are dormant over winter. In the spring, new shoots emerge. When planted in the right conditions, astilbes live for many years.
