Hedychium

[CG100]

Does anyone grow any?

Here in the UK many are hardy, but for most of the country if they are grown outdoors, in the ground, they go completely dormant during winter and the growing season is too short for them to flower. Far better to grow them in pots and keep them frost-free and get them into growth early with some extra warmth, even if provided simply by a greenhouse warmed by spring sunshine.

I have several species and most only seem to produce 1, 2, 3 shoots from new rhizome each spring, even if there is plenty of healthy older rhizome in the pot. Is this normal?

How are the pots that frequently appear online, with several growths in an 8-10-12 inch pot, produced?

[Martin Bohnet]

Here in Germany them being hardy is a rather new phenomenon (further south but occasionally continental weather), but I have some experiments going - my slugs are a problem, though, so the first one I planted out (either yuannense or tengchongense) really establishes very slowly. this spring I added densiflorum and deceptum to the outdoor experiments, too early to say anything.

Potted, the tengchongense is usually the first to flower (mid July) even though it does go totally dormant, so it's possibly the best garden candidate - also because it's only 1m tall. Next one chronologically is densiflorum (first half of August), then deceptum (budding right now). The latter two only flower this early since I stopped them from going completely dormant - they've been kept at 2°C minimum for the last 2 winters. They share a 90l mortar bucket (with added holes), that's the maximum I can move. I have a few other species and hybrids which haven't flowered yet.

As for the branching pattern: the older rhizomes can fully establish a new plant when cut from the newer tips. I guess it's hormonal suppression, so you basically have to sever the connections to get more growth. for me that's comparable to some rhizomatous iris species behaving just the same for me.

[David Pilling]

Quoting the wiki

"Hedychium densiflorum

Height:	80-100 cm (2.6-3.3 ft)
Flower Colors:	orange
Flower Season:	late summer to early autumn
Climate:	USDA Zone 7-8

'Assam Orange' is said to be one of the hardiest gingers. ... The plants shown in the photos by David Pilling were grown from seed sown in 2007 and flowered in late Summer 2008. Plants grow just over three feet high."

Good fun, but I dumped them because the floriferous bang was not worth the spatial buck.

If we count Roscoea as gingers, they have been great, easy from seed, beautiful flowers, small so keeping them in pots is easy, lasted a very long time.

[CG100]

Many thanks as ever.

Martin - your last comment about seperating the tubers makes absolute sense based on only one experiment here - horizontal supression.

(If anyone wants the most easy, beautiful Zingerbracae (that I have tried) - Globba schomburkii - a trully elegant plant, small, easily flowered, sadly scentless, and will NOT take freezing. Fabulous and most under-stated of plants, a real gem.)

I shall investigate suggestions from @Martin Bohnet - thanks.

@David Pilling - Roscoea!!! I do love this genus, although I would also have to admit that they make a hell of a lot of foliage for some rather spendid flowers. None scented?
H. densiflorum may be the hardiest, but even in the UK SW it is probably tricky to flower outside of a pot and spring warmth that cannot be provided in the vast majority of UK gardens.

I like the genus (Hedychium) for various reasons but scent is up there.
I have flowered gardenarianum as a house plant and the scent was so intense and sweet that I nearly had to stand it outdoors as it made me feel queasy.

[Robert_Parks]

@David Pilling - Roscoea!!! I do love this genus, although I would also have to admit that they make a hell of a lot of foliage for some rather splendid flowers. None scented?

No scent that I've noticed. They do well in my mock cloud forest summers. My big clump of R. auriculata has been in bloom for a few months, and will tail off next month...definitely takes up a chunk of space, the short ones don't seem to be as free flowering, but they also don't take up much space. My mild winters seem to satisfy their dormancy requirements easily (I drag the dry pots out of under the benches when the shoots break the soil).

[Martin Bohnet]

Hard to believe anyone could question the foliage to flower ratio of Roscoea when growing Hedychium. But as for moderately hardy flowering gingers I can also point to Cautleya spicata

for a cool, damp area - have to edit that wiki page, they are growing outdoors these days....

[CG100]

Roscoea in the UK are probably all hardy in most areas, most winters, but my experience is that they are not competetive, so if growing them in the open garden, they need to be marked and kept free of encroachment by neighbouring plants.

Hedychiums, I grow very largely for perfume, if and when they flower for me. I have some unscented species, but they were bought at shows and sales (as dry tubers), when there was little information available and they cost me very little money, so well worth the chance.

Even a 2m cane of H. gardenarium is hell of a thing with an inforescence that is 25-35cm long and can perfume an entire house (even if somewhat OTT in that respect). (On that score, I have several Sansevieria parva flowering at the moment - the scent is only given out eveneing and night, but that too can perfume my entire house, one spike of flowers.)

Cautleya spicata I have grown and flowered in a pot in a greenhouse, but it was not hardy, unheated. Some of the small-growing Zingerbracae, such as Kaempferia, have great foliage, and I am a sucker for any foliage that is not plain in shape or colour.

[Wylie]

Hedychium is an invasive species in the Azores. H. gardnerianum and H. coronarium are both heavily scented. I rip the tubers out, place them upside down on a rock wall, and they will continue as if nothing happened. H. gardnerianum was used in traditional bread baking, wrapping the dough in the leaves and then putting them in the wood burning ovens.

I'm trying Globba schomburgkii this year, and it seems to be doing well, but needs a lot of moisture.

[CG100]

Many of the Hedychium, in fact many of the Zingerbraceae, in cultivation are hardy or borderline hardy, although most also like plenty of water.
Frost-free, I can imagine that many will romp away and probably be evergreen.

[Robert_Parks]

Many of the Hedychium, in fact many of the Zingerbraceae, in cultivation are hardy or borderline hardy, although most also like plenty of water.
Frost-free, I can imagine that many will romp away and probably be evergreen.

Frost free, but with a distinct winter season, Roscoea has a strong dormancy, each species goes down and sprouts at its own time...not particularly linked to water or temperature...maybe there is a day length trigger in there.

Robert
where the weather is flipping between warm dry Indian Summer, and very wet fog (dry soils were wetted an inch/3cm deep this morning)

[Steve Marak]

I've grown only two, H. hasseltii and H. gardnerianum. H. hasseltii is a smaller species and I kept in in the sun room, as I'm sure it's not hardy here (NW Arkansas US, formerly USDA 6b, now 7a, FWIW). I've since lost it, which I hate because it's a great plant, attractive all the time and the fragrance of the flowers, especially at night, was wonderful. I'd love to have it again now that I have better conditions. It was not a rampant grower.

H. gardnerianum I grew from seeds donated by Alberto Grossi to BX 143 in 2007. By then we had a greenhouse and I put it in a 3 quart pot on the floor at the base of a bench. It's a much larger and more vigorous species and I can easily believe that it could be invasive in the right climate. It split that pot long ago, settled on the dirt floor, and has been going strong since with no assistance from me. It flowers every year - I think another spike will be open soon - and goes dormant every fall, though late growths like this one may hang around into October or November before dying back and dehiscing neatly at the top of the rhizome. The greenhouse is always above freezing, but temps on the floor reach the 40-50 F (5-10 C) range, maybe a little lower, on cold winter nights. I believe this one is considered hardy to USDA z7, and there is so much of it I'm going to try a piece outdoors this winter, well mulched. To me fragrance is a little strong close up but quite nice when I walk into the greenhouse when it's blooming, and the inflorescences are impressive.

Steve

[CG100]

Presumably seed is not ephemeral, even if not long-lived?

Germination - gentle warmth, bottom heat?

[Martin Bohnet]

Seed at least of densiflorum is not problematic at all. no extra bottom heat needed.

[Steve Marak]

Presumably seed is not ephemeral, even if not long-lived?

Germination - gentle warmth, bottom heat?

My experience is only with those 2 species (hasseltii & gardnerianum) but for them, yes, except that I didn't find bottom heat necessary - both germinated well enough at room temperature and in a reasonable time, i.e. weeks not months.

I collected seed from my hasseltii several times over the years I had it, so more experience with it. It's been a while, but I believe I sowed it as much as 5 or 6 months after collection, stored at room temperature, and didn't notice any difference in germination. But years later, after I lost the plant my friend sent me and had given away all the offspring, I found some old seed I'd saved and didn't get any germination.

Steve