[citation needed] Foliar feeding was earlier thought to damage tomatoes, but has become standard practice.
[citation needed] H. B. Tukey was head of Michigan State University (MSU) Department of Horticulture in the 1950s.
[4] A spray enhancer, called a surfactant, can help nutrients stick to the leaf and then penetrate the leaves' cuticle.
[citation needed] Foliar application has been shown to avoid the problem of leaching-out in soils and prompts a quick reaction in the plant.
Foliar feeding is generally done in the early morning or late evening, preferably at temperatures below 24 °C (75 °F), because heat causes the pores on some species' leaves to close.