TOW Roscoea

Jane McGary
Mon, 10 Feb 2003 11:53:03 PST
Just to offer a view of Roscoea from the Pacific North American point of
view, following the excellent introduction by Robert Hamilton:

Like most East Asian bulbous plants, roscoeas need summer irrigation and
excellent drainage in winter to flourish in the Pacific Northwest. (Their
normal climatic regime is just the reverse of the "Mediterranean" one.)
Those I have grown are R. cautleyoides, R. humeana, R. scillifolia, and R.
purpurea. Only the first-named survived for a long time in the garden, and
I think it is the most commonly grown in the UK also. They do better in
gardens at lower elevations than mine where the soils tend to be peatier
and more retentive. They are much preyed on by slugs, which of course love
the shady, moist sites  that roscoeas also favor. Thus, roscoeas are plants
for the cooler, maritime garden, to be planted among other summer-growing,
shade-tolerant exotics such as Asian asarums (another slug favorite). 

One interesting thing about these plants is that the flowers seem to become
larger year by year as the plant ages. Young seedlings are not impressive
in flower, but wait 3 or 4 years and they will look better. They are easily
grown from seed, but germination is erratic. The ovary with the seeds can
be hard to find -- in some species at least, it is far down in the
sheathing leaves.

The plant commonly grown in North America as R. alpina is likely to be R.
scillifolia, which was distributed by several nurseries under the former
name for a number of years.

Jane McGary
NW Oregon

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