Make a donation
Join the RHS today and support our charity
Read our latest features
Free access to RHS Gardens
and access to member show days
Reduced prices on RHS Garden courses and workshops
Books & Gifts
020 3176 5800
Mon – Fri | 9am – 5pm
Make a donation
Register for free to receive our newsletters, add comments to blogs/articles and to save content.
We have combined these two powerful search tools into a single Find a Plant service searching over 250,000 plant records.
Virtually all of the features of the old searches are still available and in addition we have added several new features to create a more comprehensive and user friendly search experience.
When using this search
Search by plant name, key attributes or both to find plant details and a list of
AGM plants have been through a rigorous trial and assessment programme. They are:
© RHS 2002
the RHS today and get 12 months for the price of 9
Other common names
Alnus are vigorous deciduous trees and large shrubs with rounded leaves and often conspicuous catkins in winter
'Imperialis' is a slow-growing medium-sized tree of conical outline and elegant habit, the leaves deeply pinnately lobed. Male catkins purplish, fruits small, cone-like
All ratings refer to the UK growing conditions unless otherwise stated. Minimum temperature ranges (in degrees C) are shown in brackets
Aspect North-facing or East-facing or South-facing or West-facing
Exposure Sheltered or Exposed
MoistureMoist but well-drained, Poorly-drained
SoilLoam, Chalk, Clay
pHAcid, Alkaline, Neutral
Higher than 12 metres
Time to ultimate height
This genus is noted for its ability to thrive in poor, wet conditions and is widely used in land reclamation
Propagate by seed or hardwood cuttings
Suggested planting locations and garden types
Pruning Pruning group 1
Pests Can get alder sucker and leaf-mining sawflies
Susceptible to Phytophthora
RHS members can get exclusive individual advice from the RHS Gardening Advice team.
We're a UK charity established to share the best in gardening. We want to enrich everyone's life through plants, and make the UK a greener and more beautiful place.
Like this page on facebook
Click on the Tweet button below to compose your tweet.
Join the RHS today and get 12 months for the price of 9