Publications

Plant bulletins

The results of major trials are now being produced in full colour bulletins. They include full descriptions of the Award of Garden Merit plants, comprehensively illustrated. Background botanical and cultivation information is also included as are useful selection tables, comparing the different entries in the trial.

The bulletins are compiled by the scientific and horticultural staff at Wisley, with advice and assistance from our Plant Committees.

If you would like a printed copy please contact: The Trials Office, RHS Garden Wisley, Woking, Surrey GU23 6QB. Please enclose an A4 SAE. They cost £2 per copy (a donation towards costs); cheques to be made out to Royal Horticultural Society.

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Clematis alpina and C. macropetala NEW

This bulletin follows the trial of Clematis alpina and C. macropetala at RHS Garden Wisley. The trial was initially grown at a site in Wisley Village, planted in 1997. Plants did not establish well and many suffered from late frost damage. The trial was propagated in 1999 and planted in April 2001 at Howard’s Field in Wisley Garden. The objectives of the trial were to compare and assess old and new cultivars, recommend the AGM to those considered the best and check nomenclature. There were 16 AGMs awarded.

To view a hi-res version of the  Clematis alpina and C. macropetala  Bulletin (1.07MB) click here

To view a lo-res version of the  Clematis alpina and C. macropetala  Bulletin (518KB) click here

Perovskia Bulletin

This bulletin follows the trial of 11 Perovskia at RHS Garden Wisley. The aims of this small trial were to sort out the correct identity of individual cultivars, especially ‘Blue Spire’, highlight Perovskia as a useful late-flowering shrub, assess for the Award of Garden Merit and to make a permanent record through herbarium specimens. There were six entries of 'Blue Spire', four of which were considered to be correct. The Award of Garden Merit (AGM) was re-confirmed for 'Blue Spire'. The bulletin gives details of the trial, including cultivation notes and a cultivar selection guide.

To view a hi-res version of the Perovskia Bulletin (522KB) click here

To view a lo-res version of the Perovskia Bulletin (353KB) click here

Caryopteris Bulletin 

This bulletin follows the completion of a trial of 41 Caryopteris at RHS Garden Wisley. The Award of Garden Merit (AGM) was conferred on four entries, with a further two re-confirmed. The bulletin gives details on all AGM cultivars, as well as a further 15 cultivars, and information on cultivation and origins of the Caryopteris genus. 

To view a hi-res version of the Caryopteris Bulletin (807KB) click here

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Herbaceous Sedums

This bulletin follows the completion of a trial of 90 Sedums at RHS Garden Wisley. The Award of Garden Merit (AGM) was conferred on nine entries, two of which were subject to nomenclatural resolution and one subject to availability. The bulletin gives details and pictures of the AGM cultivars, as well as providing information on cultivation and taxonomy of Sedum.

To view a hi-res version of the Herbaceous Sedums Bulletin (2.9MB) click here

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Runner Beans 

This bulletin follows the completion of a trial of 48 runner beans at RHS Garden Wisley. The Trials Office also distributed seeds of 26 currently available cultivars to East Ruston Old Vicarage Garden (Norfolk) and to eleven members of the National Vegetable Society (NVS) for trial in other regions, ranging from Hampshire to central Scotland and westwards to Gwynedd, North Wales. The bulletin gives details of 16 runner beans awarded an AGM.

To view a hi-res version of the Runner Beans Bulletin (1.4MB) click here

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Hardy Geraniums - Stage 3 NEW

The first two stages of the trial of hardy geraniums included plants suitable for general border use. However, stage 3 of the trial features plants with more specialised cultivation requirements, including those suitable for rock gardens. There were far fewer hybrids among the Stage 3 plants than in the previous stages and most were selections of Geranium macrorrhizum , G. maculatum , G. nodosum , G. phaeum and G. sylvaticum . Many of the plants in the Rock Trial were selections of G. subcaulescens or hybrids of that species included in G. lindavicum and Cinereum Group. The bulletin contains details of 12 hardy geraniums awarded an AGM and eight that were reconfirmed.

To view a hi-res version of the Hardy Geranium - Stage 3 Bulletin (2.2MB) click here

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Bearded Iris Bulletin

This bulletin follows the completion of a trial of 151 Median Bearded Irises and 112 Tall Bearded Irises at RHS Garden Wisley. The bulletin gives details of 90 AGM award-winning bearded irises in this group. It contains pictures and descriptions of each AGM cultivar, plus advice on cultivation and Bearded Iris classification.

To view a hi-res version of the Bearded Iris Bulletin (2.3MB) click here

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Begonia Rex Cultorum Group Bulletin

This bulletin follows the completion of a trial of 87 cultivars at RHS Garden Wisley. The Bulletin gives details of the 25 AGM award-winning begonias in this group. It contains pictures and comprehensive descriptions of each AGM cultivar, plus advice on cultivation and propagation.

To view a hi-res e-book version of the Begonia Rex Cultorum Group Bulletin (2.75MB) click here

To view a lo-res version of the Begonia Rex Cultorum Group Bulletin (710KB) click here

Canna Bulletin

This bulletin follows the completion of a trial of 152 canna cultivars at RHS Garden Wisley. The Bulletin gives details of 22 AGM award-winning cannas. It contains pictures and comprehensive descriptions of each AGM canna, advice on cultivation, possible threats from pests and diseases and details of other cannas in the trial.

To view the Canna Bulletin (691KB) click here

Delphinium Bulletin

This bulletin contains details of the 40 Delphinium cultivars that have been awarded an AGM after trials at RHS Garden Wisley.

To view the Delphinium Bulletin (753KB) click here

Hardy Fuchsias

This bulletin contains details of the 11 hardy fuchsias that have been awarded the AGM, plus the 40 cultivars retaining their AGM from a previous trial.

To view the Hardy Fuchsias Bulletin (790KB) click here

Hardy Geraniums - Stage 1

The majority of entries in Stage 1 were cultivars, hybrids or variants of the following species: G. asphodeloides , G. clarkei , G. collinum , G. gymnocaulon , G. himalayense , G. ibericum , G. magnificum , G. oreganum , G. palmatum , G. pratense , G. pyrenaicum , G. regelii , G. renardii , G. ruprechtii , G. saxatile , G. transbaicalicum , G. traversii , G. yeoiplus and some South African species. This bulletin contains details of the six hardy geraniums that were awarded an AGM, and the four AGMs that were reconfirmed.

To view the Hardy Geraniums - Stage 1 Bulletin (648KB) click here

Hardy Geraniums - Stage 2

The great majority of entries in Stage 2 were cultivars, hybrids or variants of G. oxonianum , G. sanguineum and G. psilostemon . Representatives of G. endressii , G. versicolor , G. albanum , G. tuberosum , G. malviflorum , G. macrostylum , G. libani and G. peloponnesiacum were also assessed. This bulletin contains details of the 10 hardy geraniums that were awarded an AGM, and the three AGMs that were reconfirmed.

To view the Hardy Geraniums - Stage 2 Bulletin (554KB) click here

Hardy Lavender Bulletin

This has been produced following the end of a five-year (1996 - 2001) trial of lavender cultivars. The 18 AGM winners are described in full along with details of all plants submitted for trial. The Bulletin also gives growing advice and help on how to chose lavenders for different positions in the garden.

To view the Hardy Lavender Bulletin (361KB) click here

Hyacinthaceae - Little Blue Bulbs Bulletin

This bulletin contains details of the small members of the Hyacinthaceae family that were included in the trial including the 11 that were awarded an AGM, as well as the six species whose AGMs were reconfirmed.

To view the Hyacinthaceae - Little Blue Bulbs Bulletin (996KB) click here

Miscanthus Bulletin

This bulletin contains details of 60 varieties of Miscanthus with more detail on the 16 cultivars of M. sinensis that have been awarded an AGM.

To view the Miscanthus Bulletin (444KB) click here

Perennial Yellow Daisy Bulletin

This bulletin contains details of the 36 perennial yellow daisy cultivars (including Coreopsis , Helenium , Helianthus , Heliopsis and Rudbeckia ) that were awarded an AGM.

To view the Perennial Yellow Daisy Bulletin (735KB) click here

Pittosporum tenuifolium Plant Assessment

This plant assessment contains details of the AGM cultivars together with a further 42 cultivars.

To view a hi-res e-book version of the Pittosporum tenuifolium Plant Assessment (2MB) click here

To view a lo-res version of the Pittosporum tenuifolium Plant Assessment (710KB) click here

Rhododendron yakushimanum Bulletin

This bulletin contains details of the recent long-term trial and full information on the 28 varieties that have been awarded an AGM

To view a hi-res e-book version of the Rhododendron yakushimanum Bulletin (2.3MB) click here

To view a lo-res version of the Rhododendron yakushimanum Bulletin (1MB) click here

Salad Potato Bulletin

This bulletin contains details of the 10 salad potato cultivars that have been awarded an AGM.

To view the Salad Potato Bulletin (333KB) click here

Shrubby Potentilla Bulletin

A report on the RHS trial 1996-2001 with details of the trial objectives, awards recommended and descriptions of almost 100 cultivars.

To view the Shrubby Potentilla Bulletin (834KB) click here

Silver Saxifrage Bulletin

This bulletin contains details of the 15 silver saxifrages that have been awarded an AGM.

To view the Silver Saxifrage Bulletin (702KB) click here

Spiraea japonica with coloured leaves Bulletin

Spiraea japonica cultivars with coloured leaves are useful garden shrubs. In recent years a number of new cultivars have been introduced and the Woody Plant Trials Subcommittee held a trial to discover whether or not the new cultivars superseded the existing ones. Eighteen cultivars were trialled.

To view the Spiraea japonica Bulletin (241KB) click here

Sweet peppers

Sweet peppers are now a popular cultivated vegetable in the UK. This Bulletin provides details of the trial plus the 16 cultivars that received an AGM.

To view a hi-res e-book version of the Sweet peppers Bulletin (941KB) click here

To view a lo-res version of the Sweet peppers Bulletin (391KB) click here

Forthcoming titles

Dahlias
Chilli peppers
Abelia
Fuchsia triphylla hybrids