We have conducted research to show that foliar urea sprays in the fall can contribute to the total nitrogen needs of a peach or nectarine tree. The urea is taken up quickly by peach leaves and soon after translocated to more permanent structures of the tree where it is made available for new growth in the spring. The optimum timing is September or October (Timing of Foliar Urea) before major leaf senescence has begun. The urea can also be combined with zinc sulfate (Urea + Zinc) sprays that are often applied at the same time (see zinc webpage). Experiments have shown that 20 to 50% of the total nitrogen needs (How Much Urea?) of a peach tree can be supplied by foliar urea. It appears that regular soil urea (less expensive) works just as well as low biuret urea. Photos at right are typical leaf symptoms from peach and nectarine trees sprayed in the fall with urea.