layering in bulbs with other plants

Jane McGary
Thu, 21 May 2015 10:35:46 PDT
Kathleen asked about ground covers that will coexist with bulbs but not 
provide a haven for weeds and slugs.

I can't answer for the slug problem, but my larger rock garden has some 
mats of thyme (Thymus spp.) through which bulbs of various kinds emerge 
and flower successfully, and in which weeds rarely germinate. Thyme 
would not, however, outcompete weeds that spread underground. I also 
have a patch of Fuchsia procumbens (which might be a thug in Kathleen's 
coastal site) hosting a colony of the modest-sized lily Lilium davidii. 
Other bulbs here are growing in a lawn, which is getting its first mow 
of the year today, now that the bulb foliage is sufficiently senescent. 
It is a weedy lawn because of the need to let the bulbs grow, but at 
least it's flat and green. Other bulbs are coexisting with prostrate, 
semishrubby penstemons, Scutellaria spp., and a small but all too 
vigorous Epimedium. You can also put spring-flowering bulbs near hostas 
and Pulsatilla vulgaris forms, which later fill in the space with their 
large leaves.

All these combinations except the thyme assume that the bulbs are 
tolerant of some summer moisture. For those that are not, I'll be 
installing a raised, rock supported bed this summer to host dryland 
bulbs and small xeric  perennials such as Arenaria and Draba. I already 
have such a combination on a tufa rock garden.

Some growers succeed with the combination of spring bulbs and summer 
annuals, though I haven't tried this much. If you want the annuals to 
reseed, you will be faced with weeding out the cress and Epilobium among 
the tiny annual seedlings, while avoiding the growing bulbs, which would 
be a real pain.

Jane McGary
Portland, Oregon, USA

More information about the pbs mailing list