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
Begin a new search
All ratings refer to the UK growing conditions unless otherwise stated. Minimum
temperature ranges (in degrees C) are shown in brackets
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.
P. ernestii is a compact, frost-tender, semi-succulent to 25cm tall with swollen, jointed stems up to 5cm in diameter at the base. Aromatic, semi-succulent leaves are ovate to triangular with rounded teeth and are slightly hairy. Flower spikes up to 12cm long bear small, two-lipped, pale lilac to whitish flowers with darker markings in summer
'Combat' has highly variegated leaves irregularly splashed in orange, red, yellow and green. They are pointed, ovate and shallowly serrated
'James' is an evergreen, upright shrub eventually reaching to 2m tall. Its heart-shaped leaves are a rich green, softly hairy with purple-tinged, toothed margins. Spikes of small pale pink-purple flowers are held on purple stems above the foliage in summer
P. verticillatus is a prostrate evergreen perennial forming a mat to 10cm tall, with rounded, coarsely toothed leaves purple beneath, and loose spikes of purple-dotted, white flowers 2cm long in summer
P. zuluensis is an erect or sprawling frost-tender plant to 1m tall and wide with ovate, coarsely-toothed, textured, lime-green leaves. Spikes of blue to pale mauve, tubular, spurred flowers are borne on dark purple stems above the foliage from late spring into summer
Mona Lavender has showy spikes of lavender, lipped flowers borne on bushy plants. Leaves are dark green with a purple underside
'Hill House' is an evergreen, frost tender sub-shrub to 90cm tall with variegated leaves that have greyish-green centres and creamy-yellow margins. Spikes of tubular, blue-white flowers are borne above the foliage in summer
'Uvongo' has anattractive patterning of silver veins on rounded leaves backed by a pinkish underside. This trailing tender plant bears racemes of predominantly white flowers whose two-lipped structure show its family relationship to Salvia
P. oertendahlii is an evergreen perennial to 15cm in height, with trailing purple stems to 1m in length, bearing rounded-ovate, bronze-green leaves with silvery main veins and purple stalks, and erect, lax racemes of small, pale blue, 2-lipped flowers
P. argentatus is a spreading evergreen sub-shrub with densely hairy, silvery stems, grey-green leaves and small tubular bluish-white flowers in short racemes in summer
Choose from hundreds of plants, bulbs, seeds and gardening products from our online shop.
Save now on all plants
& bulbs from 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.