Astilbe Pumila

• Variety: Pumila
• Latin name: Astilbe chinensis var. pumila
• Type: Herbaceous perennial
• Flower: Lilac-purple plumes
• Height: 25cm (10in)
• Spread: 30cm (12in)
• Flowering: July–August
• Hardiness: Fully Hardy (H7)
• Pruning: Leave seedheads for winter interest; cut back in spring
• RHS AGM: Yes (1993)
• Sold as: Pot-grown plants
• Plant outdoors: Spring or autumn, in reliably moist soil
• Delivered: Spring and summer. Collection from Castle Cary also available.

Astilbe chinensis var. pumila is a dwarf astilbe with stiff upright plumes of lilac-purple flowers in July and August, reaching only 25cm — one of the most reliable dwarf perennials for a moist, shaded spot. It holds the RHS Award of Garden Merit and has held it since 1993.

Astilbe Pumila – The One Rule You Must Not Break

There is one absolute requirement for astilbe: moisture. Not occasional dampness, but reliably moist soil throughout the growing season. Get that right and Pumila is among the easiest and most satisfying dwarf perennials available — the RHS AGM (1993) reflects a plant that performs consistently well in British gardens. The lilac-purple plumes are upright, stiff, and rather elegant for a plant of only 25cm, appearing in July and carrying through into August. Deer and rabbits leave it entirely alone, which is a useful attribute. After flowering, the plumes turn tawny and remain ornamental through autumn — leave them rather than cutting, and you will have winter structure as well as summer colour.

Astilbe pumila is more drought-tolerant than the larger hybrid astilbes (it comes from dry rocky habitats in northern China, which gives it more resilience), but in British conditions it still wants moisture to flower well. Plant it alongside a pond or water feature, in a bog garden, at the shaded edge of a stream, or simply in a border where the soil genuinely does not dry out in summer. In dry soils it sulks, produces small flowers reluctantly, and looks miserable. In wet ones it forms steadily spreading clumps and rewards you year after year without much effort.

Companions for Astilbe Pumila

The moisture-lovers are the natural companions. Ajuga Catlin's Giant shares the same preference for moist, shaded conditions and its low bronze mat makes an excellent foil under the upright pumila plumes. The hostas are the classic astilbe companion — bold textural contrast and shared soil requirements. For late-season extension, Anemone Queen Charlotte takes over in August just as pumila finishes. For a year-round moist border, Viola labradorica fills gaps at ground level from spring and self-seeds gently.

Why Ashridge?

We use peat-free compost and biological pest controls throughout. Astilbe pumila is a plant we stock with complete confidence — given the moisture it needs, it simply works. The people who grow your plants pack your order and answer your questions. Every plant is guaranteed. See the full perennial range.

Frequently Asked Questions

Does Astilbe Pumila need a lot of water?

Yes — consistently moist soil is the single most important requirement. Astilbe pumila is more drought-tolerant than larger hybrid astilbes, but in a dry summer it will underperform badly. It is an ideal plant for a bog garden, a pond margin, or any reliably damp border. In ordinary well-drained beds, it will struggle.

Can I grow Astilbe Pumila in full sun?

Only if the soil is permanently moist. In full sun with any tendency to dry out, the foliage scorches and the flowering is poor. Part shade with moist soil is the reliable combination. It is one of the best perennials for a shaded damp spot precisely because so few other plants thrive there.

Is Astilbe Pumila suitable as a pond margin plant?

Yes, and this is one of its best positions — planted at the edge of a pond or stream where the soil is consistently damp. It does not grow in standing water, so keep it at the margin rather than in the water itself, but it will thrive where the roots can reach permanent moisture.

Why isn't my Astilbe flowering?

Almost certainly drought stress. Astilbes that go short of water in late spring or early summer produce small, brief, or absent flowers. Water regularly, mulch the soil in spring to retain moisture, and consider moving to a damper position if the problem recurs. Lack of light is the secondary cause — deep dry shade is the one situation that defeats astilbe entirely.

How tall does Astilbe Pumila grow?

About 25cm (10in) in flower — one of the smallest true astilbes available. This makes it particularly useful at the front of a border or between stepping stones in a moist garden where a taller astilbe would be out of scale. The clump spreads slowly and steadily to around 30cm across.