For Frost and UV Protection. This product works by putting a protective film on foliage to slow down the transpiration rate i.e. reduces moisture loss. Frost tender plants can be sprayed and will be protected for up to 3 months from frosts down to -3 degrees. Conversely protects plants from harsh UV in summer.
I have personally used this product with great success in both winter and summer. It has worked particularly well on my Buxus sempervirens Handsworthii Topiary Balls which are in full sun. I found the new foliage was getting burnt in summer, one spray with Vaporgard and no more problems. Note protection kicks in about 3 days after spraying and any new growth will have to be re-sprayed.