Roscoea 2013

Submitted by Longma on

I know there is interest amongst some members of this forum for Roscoea sp. I thought I'd kick off the season with this purple form of R. cautleyoides .


Submitted by Longma on Mon, 06/24/2013 - 12:53

This unusual coloured flower of R. humeana appeared recently as a 'first time flowering from seed plant'. The 'typical coloured form' is on the left.

Hi Lori. We ( my wife Nora and I ) garden in the North East of England, on the coast of East Yorkshire.  We experience down to - 10'c  in winter and up to 25'c in summer. Records show that this area receives around 600 mm annual rainfall, but we are situated very close to a large river system that seems to draw most of the rain to it, so our garden possibly only receives 100 to 150 mm per year. This can however fall at any time of the year!

We have found that the key ( here ) to growing Roscoeas is to avoid wet and cold. We had a particularly bad ( for us) winter a few years ago ( temps down to -20'c ), and we lost thousands of Roscoeas that were growing in pots in free draining compost that had gotten wet during mild rainy spells. However the same species in the pots that remained dry survived and grew well. All of the plants in the garden in raised beds of almost pure grit, survived perfectly. Now as soon as the seed raised plants reach flowering size, ( two to three years ), they go into deep beds of grit the next Spring ( having been washed, dried and stored in plastic bags with vermiculite over winter ).  We have found that Roscoeas must be grown very very hard. Any " goodness" in the soil leads to lush straggly growth and "soft" plants that don't survive well. Our medium in the raised beds is 90% grit, 10% soil. Over time the beds become very impoverished and this is to the good of the plants. R. scillifolia scillifolia and R. scillifolia atropupurea are incredibly tough small plants and an excellent duo to start with for anyone.  Whilst I'm rambling on, I think its also worth mentioning that dried seed ( as from the seed banks ) germinates well after a good soaking, but fresh seed comes almost 100%. Some species produce so much seed they can become a little bit weedy!

This is our experience in our conditions. Many people on this Forum grow them well also, and I'm sure under different conditions, and with different approaches.

The above post is from me but unfortunately it posted as my alter ego ! and now I can't edit it! The information still holds good though. :)

Ron, you'll probably need to log out then log back in as Longma, otherwise your new messages are listing the user as "ronaldo (not verified)".

We're very pleased with this batch of R. cautleyoides. Flowering for the first time from our own seed, the plants are approx. 4" high and of a good rich colour.

Its just the perspective giving that impression Mark. The grit bed is slightly raised, so they seem higher off the ground in that picture. Maybe they are a touch over to the top of the flowers :) . Here's a lonesome singleton from further down the slope, ( plus scale :) ).

I expect the leaves will eventually also reach around 4", but will remain tough and leathery.

Thanks Ron, the red stem (or perianth sheath?) sets off the buttery yellow flowers, you have a real winner there.  I know there are a number of named forms of Roscoea, are you looking to introduce some of your better selections?  This one would surely be a hit, and of rock garden proportions too.

My apologies Mark. I haven't replied to your post, because I wasn't aware ( no 'new post alert'! ) of it until I came to post this today. :-(

I pass my plants around to anyone interested in them, but haven't considered naming any of them. Maybe if there is one that is very different and very special........:-)

The ones you refer to have performed very well and hardly elongated at all, even as seed was set, which is most unusual. As you say a very good one for the rock garden. As I mentioned above, Roscoea will stay tight, and neat ( most clones ), only when grown in very poor, nutrient deficient soils. Any richness and most will grow very unruly and tall and look awful in my opinion. I think this scruffy growth is what puts a lot of people off growing them.

This species, Roscoea scillifolia scillifolia,  never grows badly in our experience. It is incredibly tough and is another excellent candidate for the rock garden, as it never reaches more than a few inches high.This is the first flower of the season. When we lost many many pots of Roscoea to freezing a few years ago, all of the pots of this species survived. It produces seed well and they are easily germinated. This plant has been sold by many nurseries ( and many still are doing) as R. alpina, which is a very different looking species. This is my candidate for the 'Persistent Misnomers' topic! There is a 'almost black' subspecies R. s. atropurpurea, which has the same growth habits and is another very good tidy rock garden plant. It flowers a little earlier than R.s. scillifolia.Unfortunately all our flowers were to some degree slug damaged this year, but we have had excellent seed set.

Most of the roscoeas have finished blooming in my garden.  These two were in full flower in mid-June.

Roscoea purpurea 'Purple Streaker' Roscoea purpurea 'Purple Streaker'

Roscoea purpurea 'Purple Streaker' came from Betty Lowry's garden.

Roscoea scillifolia Black Form

Roscoea scillifolia Black Form was grown from AGC-BC seed and was labeled R. alpina, which it is not.

Roscoea purpurea 'Purple Streaker'
Roscoea scillifolia Black Form
Roscoea purpurea 'Purple Streaker'