Hedychium or Ginger lilies.
This is a brief guide to Hedychium with an emphasis on growing them in the UK. These are increasingly popular plants giving a "tropical" or "exotic" feel to the garden.
Hedychium are members of the large ginger family and physically have some resemblance to culinary ginger. They have a rhizome system looking a bit like like "root ginger" that runs along at or just below soil level. The rhizomes have a fragrance somewhat reminiscent of ginger but they are not useful for flavouring food. From these rhizomes emerge tall leafy shoots which in season bear spikes of flowers at their tips. These leafy shoots may be 60 cm to 4 m tall depending on Hedychium species or cultivar. After flowering green seed pods are produced which when ripe burst open to reveal a bright orange lining and seeds covered in a bright red waxy aril.
Seed of Hedychium densiflorum 'Assam Orange'
Hardiness (cold tolerance).
Many Hedychium are cold tolerant and indeed frost tolerant but that does not necessarily make them good garden plants. There are many Hedychium that are cold tolerant enough to be grown in UK gardens but not all will flower in the garden. If you are happy with lots of jungly foliage then you can grow species like Hedychium flavescens and Hedychium coronarium in your garden but these species will not bear their fabulously fragrant flowers in UK gardens. They may be cold tolerant but they need heat to get them to flower and our Summers and Autumns are simply not warm enough. Hedychium flavescens and Hedychium coronarium will flower successfully only in greenhouses or conservatories in the UK. There are other Hedychium that will flower profusely in many UK gardens and these are listed below.
Be very, very wary of quoted temperature minima. Some unbelievably low temperatures have been reported in a recent book on Hedychium and these are now often quoted. Just because something is in a book does not make it right. A thick winter mulch will help plants survive very cold weather but it will not help them to flower. Only heat can do that.
Growing from seed.
Hedychium are easy to grow from seed and will flower after 2 to 3 years. Seed is fine for growing species but be aware that Hedychium hybridise readily. The plants you get from seed may not be much like the plant the seed was harvested from. This may not matter much to you (you may even get an interesting hybrid) but if you want a particular species it is always best to buy a plant or a piece of rhizome.
Some named forms of Hedychium like the Hedychium densiflorum cultivars 'Assam Orange' and 'Stephen' are clones and should be propagated only by division of the rhizomes. If you buy seed of named forms you risk ending up with an inferior plant that is not true to name.
The "natural season" for buying fresh seed is the Autumn and Winter.
Growing from rhizomes.
This is a better way than seed to buy Hedychium that are true-to-name. However, you need to make sure you are getting fresh rhizomes and not something that has been sitting around for ages. Many suppliers import rhizomes of common Hedychium once a year (around Jan - March) from India and there is nothing wrong in that. But rhizomes are often a bit dried up by the time they get here and the supplier may not sell them for several months after arrival, particularly if the supplier bought through a secondary wholesaler. The risk is that you end up buying something shrivelled and barely alive that will take a year or two to grow into a decent plant let alone flower. So, always ask for the history of the rhizomes and how long they have been out of compost as bare rhizomes.
The "natural season" for buying rhizomes is Spring.
Growing from potted plants.
The best way to ensure you get a viable plant that is true-to-name is to buy a potted plant. You can safely buy potted plants at any time of the year but some of them may be dormant in Winter. Some Hedychium are naturally deciduous and the leafy shoots die down to the rhizomes in Autumn. Others remain green until they catch the frost; if they escape the frost they remain green. No Hedychium is truely evergreen; some may carry leafy shoots from one year to the next and individual shoots may flower in the second year but then they die off.
Sometimes potted plants offered are tissue culture plants (micropropagated). This is a cloning technique so you should get true-to-name plants. Micropropagated plants sometimes take a little longer to come into flower than usual.
The "natural season" for buying potted plants is all year round. However, Autumn, Winter and early Spring are probably the best times to buy as in the Summer the height of the plants may complicate postage and necessitate shoots being trimmed back.
There is genuine doubt about the proper name or true identity of some Hedychium grown in the UK but sometimes suppliers do not check the latest information available from reputable websites. Here are some examples.
Plants supplied as "Hedychium aurantiacum" are forms (often not very good ones) of the very variable species Hedychium coccineum. Here are a couple of forms of Hedychium coccineum sold as "Hedychium aurantiacum" ...
... and here are some other forms of Hedychium coccineum with better (redder) flower colour.
"Hedychium aurantiacum" is a synonym of Hedychium coccineum, the correct name for the species.
Plants supplied as Hedychium yunnanense are often Hedychium spicatum.
This is Hedychium yunnanense... ... note the long filaments ...
... and this is a form of the variable species Hedychium spicatum ... ... note the short filaments.
Plants supplied as Hedychium flavum aren't. This is a real species but it is not in cultivation. Plants or seeds of Hedychium flavum are always something else. Hedychium flavescens is not a synonym of Hedychium flavum as is often stated.
Ask if the photograph featured really represents the exact plant being sold. It may just be copied from a website. Unfortunately there are several unscrupulous eBayers who willfully steal photos from reputable websites to market their own sometimes inferior products.
Growing Hedychium in the garden.
Plant them where they are going to get more sun than shade. The milder your garden the more shade they will tolerate and still flower well - at least those that are likely to flower in the garden, see the list below. Hedychium are plants mainly from monsoonal Asia so they are used to warm, wet summers and cool, dry winters. They adapt to our cool wet winters very well but they do benefit from watering in summer. They are greedy feeders too so liberal applications of fertiliser are helpful. Miracle-Gro All Purpose Soluble Plant Food or Vitax Vitafeed 111 or 214 are suitable.
Hedychium resent being dug up and moved around; this usually stops them from flowering. Newly acquired Hedychium plants may not flower in their first year (rhizomes almost certainly will not and seed will take 2-3 years to flower) but just leave them where they are. Plants should settle down and flower from the second year onwards. Do not treat them like Cannas with which they are often compared. If they don't flower by the second year there is usually something wrong with the location ... or the plant.
Growing Hedychium in pots.
Some of the smaller species are fine in 15 litre pots but the majority of Hedychium will need 30 litre pots or larger to do well. The rhizomes are very strong and can easily break pots. To avoid this, and to get the best out of the plant, they will need splitting and re-potting every other year. Do this in early Spring. If you split the plant into relatively large pieces flowering that same year is usually unaffected although as mentioned above they do tend to resent this sort of disturbance.
Unless you have a large greenhouse or conservatory and can grow plants in beds, growing in pots is best for the large range of species and cultivars that have wonderful scent but will not flower outdoors. Examples are Hedychium flavescens and Hedychium coronarium mentioned above; these are big plants best in 30 litre pots. Two excellent smaller types for 15 litre pots in the greenhouse or conservatory are 'Luna Moth' and 'Filigree'. Grown under protection, all of these have wonderfully scented flowers and can often be had in flower in November even in an unheated greenhouse. If you have a heated greenhouse or conservatory you can often have them in flower for Christmas. Keep potted plants well watered and fed during the growing season. Miracle-Gro All Purpose Soluble Plant Food or Vitax Vitafeed 111 or 214 are suitable. In protected cultivation it is essential to provide light shade.
Growing in pots allows you to try Hedychium outdoors for the summer. If the flowers start to form too late in the season for outdoor flowering you can move pots under protection to enjoy them.
Pests and diseases.
Hedychium are relatively trouble free in the garden although slugs and snails will have a go at emerging shoots in the Spring and at flowers late Summer and early Autumn.
In the greenhouse or conservatory spider mite is the biggest problem. Keeping the humidity as high as possible helps to deter spider mite and the Hedychium will love this too. You can keep the humidity high by regular misting or, in a conservatory, by installing a water feature. There are no longer any chemicals (acaricides) available on the amateur market (e.g. from Garden Centres) that are any real use against spider mite. Spraying with horticultural soft soap has some effect, but not much. Spider mite predator (another tiny mite that has a voracious appetite for spider mite) can work very well but you need to introduce the predator before the spider mite has got a real hold so careful monitoring of plants is required. In a heated greenhouse or conservatory (above about 7C) the predator will overwinter so you may not need to re-purchase annually. You can order predator from most Garden Centres or on the web.
Guide to Hedychium
Here is a brief guide to choosing Hedychium for the UK. A description of the flower colour and an idea of plant height is given. Plant height varies somewhat with growing conditions but as a guide short means less than 1m, medium means 1 - 1.8 m, and tall means 1.8 m or above. Most Hedychium have some scent but only those with the best scent are indicated.
Hedychium that will grow and flower in more or less any garden in the UK.
Hedychium coccineum 'Tara' AGM - orange red flowers, tall.
Hedychium densiflorum 'Assam Orange' - orange flowers, medium.
Hedychium densiflorum LS&H 17393 - two-tone orange flowers, medium.
Hedychium densiflorum EN 562 - two-tone orange flowers, medium.
Hedychium forrestii Hort. non Diels - white flowers, tall.
"Hedychium nepalensis" Hort. - an invalid name applied to Hedychium spicatum.
Hedychium spicatum - all types - white flowers ageing yellow, medium to tall.
Hedychium yunnanense - white flowers ageing yellow, short.
Hedychium that flower best in mild gardens or sheltered situations in the UK.
Hedychium 'Annette' - colour of flowers not known, short to medium
Hedychium coccineum EN 527 - red flowers, medium
Hedychium densiflorum 'Stephen' Sch. 870 - yellow-orange flowers, medium.
Hedychium densiflorum 'Sorung' - pinkish-orange flowers, medium.
Hedychium densiflorum Sch. 582 - pinkish-orange flowers, medium.
Hedychium densiflorum from Kalimpong - yellow (or gold) flowers, small to medium.
Hedychium 'Devon Cream' - cream flowers, medium to tall. SCENT.
Hedychium "the hybrid from Tresco" - pale cream flowers, medium to tall. SCENT.
Hedychium gardnerianum AGM - all types - yellow flowers, short to medium. SCENT.
Hedychium x raffillii ('C. P. Raffill') - reddish orange flowers, tall.
Hedychium 'Corelli' - white flowers, medium. SCENT.
Hedychium ellipticum - white flowers, medium.
Hedychium greenii - orange-red flowers, distinctive red-backed foliage, medium.
Hedychium wardii - bright yellow flowers, medium. SCENT.
Hedychium 'Elizabeth' - raspberry pink flowers, tall. SCENT. (not reliable outdoors but worth a try.)
Hedychium suitable only for cold greenhouse or conservatory in the UK.
Hedychium coccineum AGM - most types, red flowers, medium to tall
Hedychium coronarium - white flowers, tall. SCENT.
Hedychium coronarium 'Gold Spot' - white flowers splashed yellow, tall. SCENT.
Hedychium flavescens - pale yellow flowers, tall. SCENT. (This is not Hedychium flavum.)
Hedychium forrestii Diels non Hort. - white flowers, tall. SCENT.
Hedychium gracile - white flowers, tall.
"Hedychium maximum" - yellow flowers, tall. SCENT.
Hedychium stenopetalum - white flowers, tall.
Hedychium thyrsiforme - white flowers, medium.
Hedychium 'Anne Bishop' - orange flowers, tall. SCENT.
Hedychium 'Dave Case' - pale orange flowers, tall. SCENT
Hedychium 'Doctor Moy' - apricot flowers, tall. SCENT. (Variegated foliage.)
Hedychium Double Eagle' - pale yellow flowers, tall. SCENT.
Hedychium 'Filigree' - white flowers splashed orange, short. SCENT.
Hedychium 'Gold Flame - white flowers splashed yellow, medium. SCENT.
Hedychium 'Kinkaku' - shell pink flowers, tall. SCENT.
Hedychium 'Lemon Sherbet' - yellow flowers, tall. SCENT.
Hedychium 'Luna Moth' - white flowers, short. SCENT.
Hedychium 'Orange Brush' - orange flowers (if you can get it to flower),tall. SCENT.
Hedychium 'Pink Flame' - pink flowers splashed dark pink, medium. SCENT.
Hedychium "Pink hybrid" - pink flowers, medium. SCENT. ("Pink hybrid" is not a proper cultivar name and there is more than one "pink hybrid" out there.)
Hedychium 'Pink Sparks' - pink flowers (if you can get it to flower), tall. SCENT.
Hedychium 'Pink V' - pink flowers splashed dark pink, tall. SCENT.
Hedychium 'Pradhan' - soft pink flowers, tall. SCENT.
Hedychium 'Samsheri' - pink flowers, tall. SCENT.
Hedychium requiring winter heat (min. 10C).
Hedychium hasseltii - white flowers, short. SCENT.
Hedychium horsfieldii - very small and odd white flowers but lots of seed, short. SCENT.
Hedychium gracillimum - white flowers ageing yellow, short. SCENT.