Over the years there have been many suggestions for dealing with the problem. Old Estate gardeners would recommend dipping the bulbs in paraffin, disguising the sweet scent, prior to planting. Other remedies included placing bracken or holly in the hole, the use of family pets, encasing the bulbs in a basket of chicken wire or using other plants such as crown imperials to disguise the sent. Some solutions were far more dangerous, especially a 1970s recommendation for the use of red lead powder.
Fortunately, the solution appears, if not discovered by, to have been refined and proven a success by Morton Hall Gardens, the hosts of one of our annual tulip festivals. The answer is chilli powder, used in the hole and then spread generously on the surface. At Morton Hall, they can use up to 25kg a year.
Crocus planting in grass and protection with chilli powder. The surface treatment is repeated during the winter, wherever scratching by animals is apparent. Below is an extract from their Gardener's Blog. If you want to follow them here is the link Head Gardener’s Journal. Most of us face an annual battle with bulb predators in our gardens. Targets are the “sweeter” bulbs such as tulips and crocus whereas their sour accompaniments, daffodils and scilla are left undisturbed.
“Having painstakingly planted over 30,000 bulbs this autumn, we cannot wait to be rewarded by a glorious spring display.
However, our thriving wildlife has completely different plans for our treasures: Despite the fact that we leave all hazelnuts, chestnuts and walnuts to the squirrels, they still have a very keen interest in crocus and tulips. The mice and voles, on the other hand, have a great appetite for erythroniums.
While we treasure and protect our wildlife, we still believe there should be some rules of conduct. Devouring our precious bulbs is certainly not acceptable. Hence, we had to develop some defences.
Our strategy is based on one magic deterrent, which is chilli powder. While mammals do not like its taste at all and therefore keep away from treated areas, it has no effect on birds. In some cases, we coat the bulbs themselves in chilli powder, in others we sprinkle the powder on the surface of the soil after the bulbs have been planted.”