Maddenia Banner 2jpg

Rhododendron Maddenia & Related Species and Hybrids

Maddenia Rhododendrons
  • Glendoick carries Europe's largest range of these fabulous plants. 
  • Size 30cm-3m.
  • Hardiness H1-4.
  • This large group of species and their hybrids provide superb garden plants for relatively mild gardens and for cool greenhouse and conservatory.
  • Milder winters mean more of us can grow these plants outdoors and they are drought-tolerant once established.
  • Cold winters may cut them back but they often break away from the base. Many are sweetly scented (marked *) .
  • The hardiest such as R. edgeworthii, R. ciliatum, R. lindleyi etc can be grown out of doors in a sheltered site at Glendoick.
  • Most are epiphytic so they need a coarse growing medium and sharp drainage: they do well in raised beds, old tree-stumps or mossy logs in wet areas.
  • In pots allow them to become a little pot-bound and keep drish in winter.
  • They can be hard pruned after flowering to improve habit.

Rhododendron Maddenia Species

CHANGII H4 Low EM-M Yellow flowers in March-April. New introduction, one of the hardiest Maddenia, surviving recent hard winters outdoors. Oval dark green leaves.

DALHOUSIAE var. RHABDOTUM H2 Med L Cream, with crimson stripes down the lobes, late. One of the latest flowering Maddenia. Peeling bark. A show-stopper.

EXCELLENS H2-3 Med L * Large scented white. Large leaves. Useful for late flowering.

FORMOSUM 'SHILLONG'  ITEOPHYLLUM Gp. C.& H. 302 H3 Low ML-L * Scented white, flushed pink in bud. We grow this outside on a wall at Glendoick.

JOHNSTONEANUM H3 Med M Slightly fragrant creamy-yellow. The hardiest of the larger Maddenias, good outdoors at Glendoick.

LILIIFLORUM H3-4 Med L * Scented white, late. Proving hardy outdoors at Glendoick, and useful for its late flowering in June.

LINDLEYI  L.& S. (grothausii) H2-3 Med M * Outstanding, large white lily-like fls. Worth attempting out of doors in many parts of Britain: hardy outdoors at Glendoick, except in severest winters. Rangy habit. Good drainage required. ‘GEORDIE SHERRIFF’ form with good pink flushing.

MADDENII ssp. CRASSUM H2-3 2m. L * Strongly scented white flowers. Grows well at Glendoick. Best in some shade.

VALENTINIODES (VALENTINIANUM VAR. OBLONGILOBATUM) C.&H. 7186 H3-4 Low L Deep yellow, late Very different from R. valentinianum and much larger in all parts. Now described as a new species. Roundish hairy leaves. From S.E. Yunnan.

WUMINGENSE CGG 14050 NEW H2-3 Semi-Dwf  Pure white flowers in pairs. Dwarf, compact. The first introduction. Newly introduced from Guangxi.

Order Online

Maddenia Hybrids

FRAGRANTISSIMUM H2 Med M * Large scented white fls. Suitable outdoors in mild gardens. Excellent in a pot with long shoots trained around stakes. Very straggily and now superceded by better behaved hybrids.

JIM RUSSELL (CILIICALYX HYBRID) H1-2 Tall E * Large frilly light pink-white scented fls in huge trusses. One of the most spectacular Maddenia hybrids.

LADY ALICE FITZWILLIAM H2-3 Low EM-M *  Scented white fls. Similar to 'Fragrantissimum' but more compact. Hardy outdoors on a sheltered wall at Glendoick & good in a greenhouse or conservatory.

MI AMOR H1-2 Med M * Enormous scented white flowers like giant lillies One of the mosy spectacular of all Maddenia hybrids, for indoors or mildest gardens.

TINKERBIRD H3-4  Scented cream-white. A real breakthrough: a compact, scented dwarf which grows outdoors at Glendoick. Best in a sheltered site. Surprisingly bud hardy. Also good as a pot plant. Like a tougher more compact version of Lady Alice Fitzwilliam.

TURNSTONE (edgeworthii x moupinense) H3 Semi-Dwf E * White flushed pink, scented, early. Compact habit, drought tolerant. Flowers well outdoors at Glendoick. PINK pale pink flowers.

Order Online


H2-3. Smaller than the Maddenia species with charming white or yellow flowers. Usually epiphytes, so require good drainage. Most are hardy in a sheltered site at Glendoick.

DEKATANUM H(3-)4 Low E Strong clear yellow, early. Introduced by Ludlow and Sherriff. Fine peeling bark. Good on a sheltered wall at Glendoick

Order Online

Rhododendron Edgeworthia

H2-4. Hairy leaf under-surface and white or yellow flowers. Epiphytes which need perfect drainage in a raised, partly shaded bed, on a very steep bank, or on rocks or mossy logs in wet areas.

Order Online

Rhododendron Monantha

This subsection contains the only autumn-flowering non-Vireya species. they have considerable potential as parents of autumn or/and repeat-flowering hybrids. Sharp drainage essential.

CONCINNOIDES H2-3? Low VVL Pinkish-purple in Autumn. First introduction by Kenneth Cox. Needs sharp drainage.

Azaleastrum (Stamineum) Section

H2-3 Med-Tall EM-L These little-known species are fine garden plants for warm and sheltered gardens such as Cornwall and Argyll and have potential in mild parts of Spain, Portugal, Italy and France. They can form huge trees in time.

VIALII H2-3 Low-Med EM Striking red fls. Newly introduced. This is the 'real' R. viallii. Should be excellent in Cornwall.

Order Online

Glendoick Garden Centre Directions Logo

Glendoick Gardens Mail Order Nursery

Mail order for Autumn 2024 to Spring 2025 is now online

Orders are delivered/collected from 1st October to end of March  when plants are dormant.  You can order at any time of year.  Our Garden Centre has stock for collection year round.

We deliver to UK including N Ireland and Norway. We are not delivering to EU countries at present (Brexit rules). We are currently able to delivery to S. Ireland but only larger orders and there may be some extra transport costs.

Minimum Mail order £120 ex vat (UK) £500 (Norway)

Postage and packing from £21 per box of up to 30 kilos (10-25 plants)

All orders must be placed online in the webshop. Please use e mail to contact us.