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Hedychium

An annotated list of the species and cultivars grown in the UK

Introduction

This is not a definitive list of Hedychium species. This is a commentary on Hedychium species circulating in the nursery trade in the UK and cultivars that either originated in the UK or were named in the UK having originated elsewhere.  The list is drawn mainly from The RHS Plant Finder.  The list specifically excludes plants in UK botanical gardens not because they are without interest (the contrary is the case) but because they are now prisoners of the CBD.  The list also specifically excludes all American hybrids irrespective of whether they are grown in the UK or not.  A small number of names of American origin are included but these are dismissed as mere marketing names not cultivar names.

Hedychium is a genus of around 50 species in the ginger family, Zingiberaceae, from Asia. They are known commonly as the ginger lilies. Hedychium have similar spiky-looking foliage to the culinary ginger (Zingiber officinale) and sometimes have a distinct ginger smell to their rhizomes but they have no culinary value. The genus name derives from two ancient Greek words, "hedys" meaning sweet and "chios" meaning snow. The correct pronunciation is HEDICKEEUM.

Hedychium have two types of stem. The first are stout, fleshy rhizomes running at or just below the soil surface which have a so-called indeterminate growth habit.  The second are leafy shoots that emerge above ground and carry the spiky leaves that make Hedychium such striking plants even when not in flower. In all but one species these leafy shoots have a determinate habit in that the growing point either differentiates into a terminal spike of flowers or aborts. The flowers are borne from midsummer to autumn at the top of the leafy stems although not every stem will produce an inflorescence. The flowers are borne on the inflorescence in the axils of green leafy bracts that in some species roll in on themselves to form a tube from which the flowers emerge. In other species the bracts remain flat giving the inflorescence a cone-like appearance. In some species only one or two flowers emerge from each bract. In other cases up to 6 flowers emerge successively giving an extended flowering period. Flowers of some Hedychium have a very slight scent while others have a fabulous spicy fragrance, redolent of the tropics.

Flowers of the Zingiberaceae are highly modified and those of Hedychium are no exception. A guide to the floral parts of Hedychium is given here.

Hedychium vary from frost hardy to tender greenhouse or conservatory subjects. In the garden it is possible to enhance cold tolerance by planting Hedychium deep in their first year. However, the rhizomes are happiest at about ground level and the plants tend to adjust themselves quite quickly. A deep dry mulch will help protect against the worst of the winter cold. A sometimes-quoted rule of thumb with Hedychium is to try to mimic the monsoon conditions in which they naturally grow. Keep them well-watered and fed while in summer growth, then cool and dry during their winter dormancy. This can easily be achieved with plants growing under protection but is impossible in the garden. In practice, Hedychium do not seem to mind winter wet although it would be best to avoid areas that waterlog in winter. Hedychium are plants of forest clearings and forest margins so in nature they grow with a little shade. Hedychium should be grown under light shade except in marginal gardens where they are best in full sun. Keeping plants well watered in summer can mitigate the tendency for flowers to go over quickly in full sun. When grown under protection Hedychium should be grown with permanent light shade.

Hedychium are sometimes compared to Canna but there is one very big difference in their horticulture. Hedychium resent being lifted annually and stored as dry rhizomes over winter. This treatment will not kill Hedychium but it will very effectively stop them from flowering. Hedychium should preferably be left in situ in the garden over winter. If there is concern about losing the plant to frost then it should be mulched for the winter but if the right species is chosen even this is hardly necessary. Hedychium that are "evergreen" and marginal for flowering such as H. gardnerianum and H. greenii can be flowered in marginal gardens by growing them in plunged containers which are lifted in autumn. Alternatively whole clumps can be lifted and potted up for the winter but this requires more care. In each case the plants should be over-wintered under frost-free protection (min. above 5C) still in leaf so that they continue to grow slowly in winter.

The RHS has recognised 3 Hedychium by awarding an AGM, Hedychium coccineum, Hedychium coccineum 'Tara' and Hedychium gardnerianum.  For more details and a commentary on this see the relevant pages.

Hedychium can be a rather difficult group of plants properly to identify and it is hoped that this website will have some value in this respect. Wild species are variable and particularly in cultivation they tend to hybridise, so many different and sometimes obscure forms are available.  This "interesting situation" is exacerbated by nurserymen who like to give new names to ostensibly "new" plants.  There is a three-point "rule" to naming new cultivars that is almost universally ignored; a "new" cultivar must be Distinct, Uniform and Stable.  Almost always, nurserymen fail to indicate how a "new" cultivar is distinct from its antecedents, thus falling at the first hurdle.

For a fascinating review of and insight into this group of plants see the chapter on Hedychium by Edward Needham in Gardening on the Edge.  T. M. E. Branney's book Hardy Gingers covers more Hedychium but is less insightful.

Species & Cultivars

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last updated 02/10/2008

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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last updated 02/10/2008