Wilt-Pruf was discovered and became the first anti-transpirant on the market over 50 years ago. Plants suffer from losing too much water all through the year. Excessive transpiration causes stress, shock, wilting, and plant failure. Wilt-Pruf contains a film forming polymer which offers high density, good efficacy, and even coverage across foliage. Keeps trees, shrubs, sod, and indoor plants healthy and protected against plant damage due to winter kill, transplant shock, wind burn, drought, and air pollution. The unique film forming polymer produces an outside protective coating that weathers off one layer at a time providing long lasting protection for about 2 months during hot, summer conditions and 4 months during cold weather conditions. Simply spray on your plant's leaves as a protective coating. One quart size of concentrate.