Join the RHS today and support our charity
Free personalised gardening advice
RHS members get reduced ticket prices
RHS members get free access to RHS Gardens
Reduced prices on RHS Garden courses and workshops
020 3176 5800
Mon – Fri | 9am – 5pm
Help us achieve our goals
Make a donation
I have forgotten my password
Keep me signed in
Register for free to receive our newsletters, add comments to blogs/articles and to save content.
See what events are on near you and browse your bookmarked pages.
Inspiring days out and so much more
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:
This plant will provide nectar and pollen for bees and the many other types of pollinating insects.
It is included in an evolving list of plants carefully researched and chosen by RHS experts. Divided into 3 groups these lists, linked below, are maintained by a team of RHS staff and are reviewed annually.
the RHS today and get 12 months for the price of 9
Other common names
Quercus robur f. fastigiata 'Koster' AGM Quercus robur 'Fastigiata Koster'
Quercus robur 'Kosteri Fastigiata'
Quercus can be deciduous or evergreen trees or shrubs, with entire, lobed or toothed leaves; flowers inconspicuous, followed by characteristic acorns; sometimes good autumn colour
'Koster' is a fastigiate form with upright branches, spreading with age to ultimately reach 15m high and wide. Usually seed-raised so can be variable. Leaves are dark green with shallow lobes
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
MoistureWell-drained, Moist but well-drained
SoilSand, Clay, Loam
pHAcid, Neutral, Alkaline
Higher than 12 metres
wider than 8 metres
Time to ultimate height
more than 50 years
Grows well in most deep, fertile soils and is lime tolerant
Propagate by seed, sown as soon as ripe, in a cold frame
Suggested planting locations and garden types
Cottage & Informal Garden
Pruning Pruning group 1
Pests Susceptible to aphids, caterpillars, leaf-mining moths and oak gall wasps
May be affected by powdery mildews. Also oak wilt in USA only
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.
Join the RHS today and get 12 months for the price of 9