Answer: Unfortunately, I have no personal experience with critters eating begonias in the garden, although I do have experience with squirrels and deer devouring plantings. In my experience, the squirrels tend to leave the summer bulbs alone, probably because there are other foods available at that time of year and they are digging less to begin with. Watering well at planting time so that the soil is settled instead of fluffy also seems to help discourage them. You could cover the area with chicken wire as a deterrent, and allow the bulbs to sprout and grow up through the wire. There are also repellents available that you could try for extra insurance.
Deer seem to eat almost anything if they are very hungry, and they are creatures of habit. They will browse repeatedly in one area and may try new plants nearby. They will learn to eat new types of plants over time, too. There are repellents you could try, but if the deer are already a problem in your garden you might want to keep in mind that the most effective deterrent over time is a tall fence.
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