The Q&A Archives: Protecting Bulbs from Rodents

Question: Is there any way to protect bulbs from moles and other rodents? I used an organic product called Bulb Insurance which consists of crushed oyster shells. Will this really work?

Answer: Moles don't usually eat plant matter, preferring insects.
Rodents such as mice and voles use their tunnels like a subway, and they do eat roots and bulbs. Moles tunnels are usually marked by raised soil and a soil pile around the exit hole. If there isn't a heap like this near the hole, then your culprit is probably a mouse, chipmunk or vole. The idea behind Bulb Insurance is that if mixed with the planting soil around your bulbs, and if rodents burrow near, the sharp shards make it tough digging and they go elsewhere. Since you've applied it, you'll be able to tell whether it works in your situation fairly soon. For most pests in the garden, you generally need to try a few different strategies, together and at different times, to keep the pests off balance. Animals are smart little critters and they can soon grow accustomed to our attempts to foil them!

A more permanent solution would be to plant your bulbs in wire mesh cages or try surrounding the bulbs with coarse gravel when planting. If your problem is above ground pests such as rabbits, deer, or squirrels, there are repellents
such as Ro-pel, Bonide rabbit-deer repellent, hot pepper spray, garlic, bloodmeal, and vinegar. Repellents can also be applied to the bulbs before planting. Moles evidently hate the smell of castor oil beans, and Gardener's Supply Catalog has a repellent out with castor oil as an ingredient that I have heard good reviews about. You can reach them at 1-800-863-1700 or visit their website

You could also plant the entire bulb area in a cage! You need to excavate the garden area to a depth of 18-24" and line it with an underground barrier of hardware cloth. If you splice pieces of the hardware cloth together to fit the space, be sure to overlap them to prevent a chink in your garden's armor! Overlap the corners as well. A great side-effect of this effort is a well-areated soil - you can use it as an opportunity to mix organic matter into your garden!

I hope some of these ideas help!

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