Join the RHS today and support our charitable work
Free personalised gardening advice
RHS members get reduced ticket prices
RHS members get free access to RHS Gardens
Free entry to RHS members at selected times »
Reduced prices on RHS Garden courses and workshops
020 3176 5800
Mon – Fri | 9am – 5pm
Help us achieve our goals
Join the RHS today and support our charity
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
Californian tree poppy Californian poppy
bush poppy canyon poppy dream of the desert giant white Californian poppy Matilija poppy
Romneya are suckering subshrubs with pinnately lobed leaves and large white flowers in summer
R. coulteri is a vigorous, suckering herbaceous perennial to 2m in height, with divided, grey-green leaves and poppy-like flowers 15cm in width, with crinkled, pure white petals and a boss of deep yellow stamens
All ratings refer to the UK growing conditions unless otherwise stated. Minimum temperature ranges (in degrees C) are shown in brackets
Aspect South-facing or West-facing
MoistureWell-drained, Moist but well-drained
pHAcid, Alkaline, Neutral
Time to ultimate height
Grow against a warm, sunny wall protected from cold winds. Mulch deeply prior to winter. They dislike transplanting but once established it can spread, so site with care
Propagate by basal cuttings in spring, root cuttings in winter or propagate by seed sown in spring at 13°C to 16°C
Suggested planting locations and garden types
Drought Resistant Wall-side Borders
Mediterranean Climate Plants Cottage & Informal Garden
Pruning Pruning group 6
Pests Caterpillars may be a problem
Powdery mildews may be a problem
RHS members can get exclusive individual advice from the RHS Gardening Advice team.
Californian tree poppy
Buy from £27.99 at the RHS Plants Shop
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.