Answer: Deer can be very destructive, if your garden is on their browse trail then they will come back again and again. During winter, or when the population increases, the browse pressure will be even more severe. The first suggestion with regard to deer is to erect a tall fence; in my experience this is the only reliable solution in the long term.
Some gardeners report success using the spray-on repellants. These are sold at garden centers and nurseries. They must be applied and reapplied per the label instructions and this can be time consuming (and expensive) if you have many plants. Some gardeners find it is more effective to alternate between different brands so the deer are kept off guard.
You might also check with your neighbors and see which plants seem to be less bothered by your local deer. (Deer are adaptable and will learn to eat different plants depending on what is available, so a list of "deer resistant" plants can vary from area to area.) Your local county extension may also have suggestions.
Rabbits tend to be somewhat cyclical in population, so you may find some years are worse than others. Encouraging their natural predators can be helpful, such as foxes, snakes and birds of prey.
There are spray-on rabbit repellants that can be used on individual plants similar to the deer repellants. Fencing is again a long term solution. You can use a wire mesh about two feet high and also bent outward flat along the soil to deter tunneling under it. This can be used as a trunk wrap on individual trees or to surround a garden area. Electric fencing can also be effective against rabbits.
I hope this helps.
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