Introduction

Astilbe are members of the Saxifrage family and are a native plant of Asia. They can grow to a height of over 1m. Astilbe grow from a tuberous root system. The foliage resembles fern fronds and the flowers have a feathery appearance. Colours range from whites through to pinks and reds. Astilbes require a cold period of dormancy before they are able to flower. They also prefer moist soils and growing in areas similar to Hydrangeas. Production from New Zealand is relatively new, with only small volumes going to the market. Astilbe seem to grow best in areas with low temperatures and long days. This may give the Southern regions of New Zealand a competitive advantage. They can be forced to flower out of season if grown in glasshouses.

Growing Astilbe

Propagation: Astilbe are produced from seed or by division.
Division is the most desirable methods for cut flower varieties. Seed grown material is suitable for the Nursery/Garden Centre trade.
Yields/ha: Year 1 0.5 stems/plant,
Year 2, 3 stems per plant,
Year 3, 5-6 stems per plant and then divide plants.
Planting depth: Division buried just below ground level.
Training/Pruning: Cut back in winter.
Time of flowering: Mid January - Mid February.
Crop protection: General wind protection only, crop support not needed.
Soil type: Astilbe grow best in fertile, moist, well drained, slightly acidic soils with a pH 5.5 – 6.3
Fertilisers: Applications of NPK fertiliser are needed.
Weed control: Start with a clean seed bed and the Astilbe out-compete most weeds during the course of the season.
Pest/Diseases: Some spittle bug, thrips a major problem during harvest. Insecticide and fumigation essential.
Harvesting: Cut stems leaving at least 1 set of leaves.
Marketing: Export markets in Asia and Europe