ground cover for summer dormant bulbs

Jim McKenney
Wed, 27 Jul 2005 05:23:35 PDT
One plant which works very well in our climate for this purpose is Begonia
grandis (B. evansiana). There are many perennial plants which can be planted
over bubls, but the particular advantage of this begonia is its late
emergence. It makes little if any light competition for vernal ephemerals.

It's very handsome in late summer/early autumn when it blooms, too. The
flowers themselves are ornamental, and so too are the developing seed

It's big: plants are easily thirty inches high, and individual leaves can be
5 inches by 8 inches or more. 

It's just about weedy here, but in a cooler climate is probably much more

Another one to consider is Begonia sutherlandii. In this area this one is
marginally hardy: some growers report it to be reliably perennial, others
report occasional or frequent winter killing. This one is much smaller, only
about eight inches at the most, and eventually has bright orange flowers. 

Another unseemly choice for this climate are the various Mexican Oxalis.
These seem to survive the winter reliably, but do not begin to grow until
very late in the year - sometimes not until June. The ones which work best
here are O. regnellii, O. corymbosa 'aureoreticulata', O. deppei, and in
sheltered places O. lasiandra. 

Another thing to consider: many annuals, especially those which take three
or four months to mature from seed. Sometime around the middle of June
self-sown Impatiens wallerana begin to bloom in this garden. By then, plants
bought earlier in the year from suppliers of bedding plants have been in the
ground for perhaps two months, and these self-sown plants are tiny in
comparison. But in the heat and humidity of our summers, they grow rapidly. 

Cuphea ignea is another one I like. 

Jim McKenney
Montgomery County, Maryland, USA, USDA zone 7, where I was out in the garden
early this morning to take photos - only to have the camera lens fog up in
the heat and humidity. 

-----Original Message-----
From: []
On Behalf Of
Sent: Wednesday, July 27, 2005 2:31 AM
To: Alpine-L, the Electronic Rock Garden Society; postings copyright by
Cc: Pacific Bulb Society
Subject: [pbs] ground cover for summer dormant bulbs

Every year, about this time, I am vexed by the sight of bare soil where the
spring bulbs have gone dormant. I hate bare soil as it seems such a wasted
opportunity to be growing something, so I am looking for plants to form a
low carpet over these areas. Ideally these should be perennial, need no care
or supplementary water, form a mat over the area, but not offer any
resistance to an emerging shoot, or any competition to the growing bulbs
that are the most important occupants of the space.

Certain Sedums are suitable, and in a rock garden setting there would be
many options from the genus, but the areas I need to cover are in a
'woodland' garden with shade for part of the day. Yesterday, taking
advantage of moistish ground and the forecast of two or three days of wet
weather (yippee!) I put out some plants of Pratia pedunculata and Leptinella
(Cotula) 'Platt's Black' over snowdrop patches. Last year I used a rather
good bright green Leptinella that I had from Wayne Roderick (any suggestions
for identification would be welcome!). It has tolerated the conditions quite
well, but for some obscure reason I only planted it in areas where there is
only a narrow fringe of 'bare' ground between thick herbaceous plants and
the edge of the bed. In other areas there are several square feet of bare
ground to cover in the case of the bigger patches of snowdrops, so some
vigour is needed.

I should be very interested to hear what other people use or could suggest.

John Grimshaw

Dr John M. Grimshaw
Garden Manager, Colesbourne Gardens

Sycamore Cottage
Nr Cheltenham
Gloucestershire GL53 9NP


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