Neighborhoods with old, mature trees are often full of tree squirrels. Rocky places and areas with lots of brush may have large populations of chipmunks—another member of the squirrel family. Tree squirrels (Sciurus spp.) and chipmunks (Tamius spp.) can be the bane of gardeners who like to plant spring-blooming bulbs, such as tulips.
Squirrels and Bulbs
A large population of tree squirrels or chipmunks can make it virtually impossible to grow large numbers of tulips or some other bulbs, without extensive control measures. Because these rodents cannot digest cellulose material, they depend on protein-rich plant structures such as nuts and bulbs to survive.
Gardeners are a squirrel's best friend since the squirrels love digging to find (and hide) nuts and plant bulbs. Experienced squirrels have known to sit and watch gardeners plant their bulbs, anticipating a feast. Fall bulb-planting season is especially tricky since this is when other food sources are beginning to dwindle for squirrels. Luckily, there are several things you can do to keep your bulbs in the ground where they belong.
Protect the Bulbs
One of the most fail-safe ways of protecting your bulbs from ravenous squirrels is to cover them with either chicken wire or hardware cloth. Hardware cloth is a metal mesh, much like chicken wire, except that it uses a smaller grid pattern, usually about 1/2 inch square. There are two general ways to use either chicken wire or hardware cloth to protect your bulbs:
- Cut a section (of either material) that's large enough to cover the overall size of your planting area. Next, lay it on top of the soil once you're done planting the bulbs. Secure it in place, either with stakes or by weighing it down with rocks or bricks. Then, cover it over with a mulch of shredded leaves or bark to hide the wire. The stems will come up through the holes in the chicken wire or hardware cloth, but the bulbs themselves will be protected from digging squirrels. This technique works best in open areas where you won't have to work around perennials or other plants.
- Use chicken wire or hardware cloth to make simple cages from the wire mesh, place the bulbs inside, and plant the assembly in the garden. These enclosures are especially effective if you have tunneling animals in your yard, such as moles, that also feed on bulbs.
Avoid Smelly Fertilizers
Bone meal, fish emulsion, and some other natural fertilizers have a pungent aroma that may attract squirrels and chipmunks—not to mention digging dogs and cats. Avoid these natural fertilizers in favor of synthetic fertilizers that have no odor.
Plant Bulbs Among Other Plants
When you plant spring bulbs among established groundcovers or other perennials, squirrels have a harder time finding them and digging them out. Planted beneath an expanse of creeping vinca, for example, bulbs are usually ignored by squirrels. Another advantage is that the spring bulbs will supply early color to bare areas before the summer perennials begin to fill in.
There are several natural, organic repellents on the market. Don't limit yourself to squirrel or rodent repellents; organic deer repellents will work, as well. Another natural repellent that's effective against squirrels is red pepper flakes. A liberal sprinkle of red pepper flakes over planted bulbs can do an excellent job of discouraging hungry squirrels from digging.
Add Sharp Gravel
If you're planting a few bulbs in an established garden bed, consider adding some sharp gravel to the surrounding soil. When squirrels encounter jagged material, they'll leave to find a new place to scavenge. You can find sharp gravel in home improvement centers or landscape supply yards—it's often used to provide drainage under paved surfaces. Crushed oyster shells, which have an unpleasant gritty texture, may also deter squirrels from digging.
Provide Alternate Food Sources
The theory behind setting up a squirrel feeding station is that if the squirrels have accessible grains and nuts, they won't bother trying to dig up your bulbs. This method is controversial, as some experts say that the food merely attracts more squirrels to your yard, where they will dig up your bulbs anyway. In areas where squirrel infestations are unusually heavy, it may even be against local ordinances to feed squirrels and other wild animals.
Disguise Your Planting Areas
When you're finished planting your bulbs, be sure to pick up any papery bulb husks, bad bulbs, or other debris. Such materials attract the attention of squirrels, who will start digging to see what other goodies you've left lying around for them.
Plant Bulbs That Deter Squirrels
Squirrels are very fond of some bulbs, such as tulips and crocus, but there are other spring-blooming bulbs that they don't like. You can either replace your tulips entirely with these bulbs or mix them in among the tulips. A few bites of some bitter-tasting bulbs may send the squirrels away from your yard. Good bulbs for deterring squirrels include:
- Alliums (including onions and garlic)
- Muscari (grape hyacinth)
Delay Planting Time
The squirrel and chipmunk feeding frenzy peaks in early autumn, but begins to quiet down a bit by late October, when the rodents have already stored away most of their winter supply. If possible, plant your spring-blooming bulbs somewhat later in the fall, when squirrels are no longer desperately filling their stores.
How Can I Keep Squirrels From Digging up Newly Planted Tulip Bulbs? Iowa State University Extension
Bulbs: Now You See Them, Now You Don't! University of Pennsylvania Extension, 2017
Questions and Answers - Bulbs & More. University of Illinois Extension
How to Protect Fall Bulbs From Chipmunks and Squirrels. Longfield Gardens