moles, voles, and other devourers of geophytes.

Jim McKenney
Fri, 16 Dec 2005 10:25:03 PST
I've trialed several Euphorbia here, some as ornamentals and some for their
purported ability to deter rodents. 

The one with the oldest and most widespread reputation is the mole plant,
aka gopher spurge aka gophers purge, Euphorbia lathyris. My experiences
suggest that it is useless for repelling rodents. I'll admit that I've never
seen a mole tunnel or a vole run which goes under one of these plants, but
if the Euphorbia is there, a bulb isn't. I happen to like this plant, and
there are usually a few here and there in the garden. But I don't expect
them to repel rodents. 

From what I've read, Tagetes are supposed to be good for getting rid of
nematodes. Until I read Adam's post, I had never heard that they were good
for repelling rodents. 

John Bryan asked why some bulbs are devoured and not others. One reason is
that some contain bitter compounds of magnesium (or is it manganese? I
always get those mixed up.) which make them unpalatable to all but starving
critters. Certain lilies such as Lilium henryi and its hybrids, L. hansonii
and its hybrids, are good examples. 

Jim McKenney
Montgomery County, Maryland, USA, USDA zone 7, mid-forties today with warm
sun after several days of unseasonably cold weather. Protected crocus are
still blooming outside. 

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