Hi Diane:

(I sympathize! I have great neighbors who love to feed squirrels and my gentle verbal suggestions haven’t worked to solve this problem —even when I suggest that feeding wildlife is against the law).

So here is what I found when I researched the problem:

https://hortnews.extension.iastate.edu/faq/how-can-i-keep-squirrels-digging-newly-planted-tulip-bulbs

The above link from Iowa State University suggests planting bulbs at correct depth or even a bit deeper —6-8 inches deep—which will slightly delay blooming (to keep squirrels from digging as much) then watering and tamping down the soil firmly. They also suggest placing chicken wire over the bulbs at planting time so squirrels can’t dig through.

Other suggestions follow:

https://www.humanesociety.org/resources/squirrel-damage-your-yard-and-garden

the above link from Humane Society suggests the following:

“Trees

Small fruit and nut trees can be protected by netting the entire tree for the short period when squirrel (or other animal) damage is most likely. Fruit trees may be protected by wrapping a two-foot band of sheet metal around the trunk about six feet off the ground, as long as the squirrels cannot jump on them from adjoining trees. Do not to leave the bands on any longer than necessary, since insect damage might occur and the trunks of sensitive trees may get sun scald (the freezing of bark following high temperatures in the winter season, resulting in permanent visible damage) if bands are removed after a long time. Branches growing below six feet also may have to be trimmed.

“Flower bulbs

Squirrels will dig up and eat tulip and crocus bulbs, but they don't like daffodils, so consider investing your bulb-planting energies in daffodils. For other bulbs, soak them in a repellent with Thiram as the active ingredient (and labeled for use as a squirrel repellent) before planting. Lay chicken wire over the planting bed or use wire bulb cages.

“A note on squirrel repellents

There are several repellents on the market that may deter squirrels. In addition to repellents with Thiram as the active ingredient, there are ones with capsaicin or oil of mustard as active ingredients, which you can spray on plants when they first emerge in the spring. You can also use these repellents on patches over squirrel entry holes in buildings to discourage gnawing in attempts to re-enter.

Capsaicin products are also used to coat birdseed to repel squirrels.

The sticky gels that are marketed to deter squirrels from climbing on branches or other surfaces are dangerous to other wildlife, particularly birds, and inappropriate for wildlife control, not to mention that they can cause damage to surfaces on which they are placed. We don’t advise you to use them.”

Another link:

https://www.thespruce.com/protecting-bulbs-from-squirrels-2539825

Extensive suggestions from the above link are included, such as barriers; chicken wire over bulbs at planting time; planting later in fall when squirrels have less interest in storing your precious bulbs; natural repellants (I have found these to be not so effective).I have also read that used cat litter spread in planting beds can help but I haven’t tried that. Many ideas are not scientific and may be ineffective.

This is a difficult problem and workable solutions seem to be scarce; I hope some of the ideas will be helpful. Good luck!