Geophytic Delphinium species, was Delphinium carolinianum

Jane McGary
Wed, 13 Jul 2011 10:04:47 PDT
My main experience with American geophytic Delphinium species is with 
Delphinium luteum and D. nelsonii. Both of them settled down well in 
my old bulb frames and seeded around. I was able to bring D. luteum 
over to the new garden in some pots and also in some discarded bulb 
soil that had seeds in it. and it flowered well on the slope here 
this spring where I have the beginning of a rock garden devoted to 
non-fussy plants.

I've tried to share this species with others (it's endangered in the 
wild, but I got the original seeds from the Robinetts many years ago, 
quite legitimately) by giving them dormant roots. However, this 
didn't work out well. I think it's better to grow new plants from 
seed and not disturb them unnecessariily.

My new project here is building a tufa rock garden. I bought enough 
tufa (water-deposited calcium carbonate rock) to make one large bed 
and one smaller one. The large bed will be a typical "crevice" garden 
for lime-tolerant shrubs and perennials, with a very gritty 
underlying soil, but for the smaller one I think I'll try to imitate 
a rocky pavement with a more retentive soil and have a lot of bulbs 
from limestone areas on it. I may have to bring the "dirt" for it 
from my former home -- still for sale (Anybody want ten acres? With 
bulbs in it?) -- because the native soil here is excessively dense 
clay. I've visited limestome areas in the Mediterranean so I have an 
idea what grows there, but if anyone has experience planting 
geophytes on a tufa garden, I'd like to hear about it.

Jane McGary
Portland, Oregon, USA

More information about the pbs mailing list