For more than one gardener, a spray on deer repellent comes in the form of a 12 gauge shotgun. While this method might be effective in the short-term, in the long-term it simply does not work. The smart gardener will find a product that will provide 24-hour protection to their plants without the need for anyone to stand watch.
There are many high-quality deer repellents available on the market today. The majority of these will last up to four months with a single application and can be used all year round. The trick when using them year-round is to ensure that before applying them to the plants, that the plants are completely dry.
The plants being dry, insures that the deer repellent mixture sticks to the leaves and stays there. There are some varieties of deer repellents that actually spray on as one color but dry as another. This shows the gardener that he has in fact covered every square inch of the plant with the repellent, protecting all of it.
For those gardeners who feel a more natural approach is necessary, there are many homemade repellent recipes available online that can aid them. These recipes use common household items to naturally repel the deer and prevent any damage to the plants, the soil or the deer themselves. This is not to say that the commercial deer repellents in any way cause any damage, as many of them are designed to be eco friendly.
Whichever method is chosen, be sure to apply the deer repellents as liberally as possible. The commercial repellents along with the homemade recipes will all have instructions on the proper application methods necessary. The majority of these, if not all of them, simply need to be sprayed directly on the plants by means of a trigger sprayer or 2 gallon pump type sprayer.