Thin fruit when fruit reaches thumbnail size: peaches, nectarines, apricots, apples, pears, Asian pears, plums and plum relatives. Needing no thinning are figs, pomegranates, persimmons, all nut trees.
Begin spraying nectarine fruit with spinosad immediately AFTER flowers drop for control of Western flower thrips (ugly and sappy nectarines)
This is iron chlorosis. Foliar iron fertilizers can be applied if you missed your soil application of iron. This may take multiple applications while the temperatures are cold.
This is a good time to put in limb spreaders on apples, pears and Asian pears. The branches will bend easily now on limbs one or two years old.
Ground squirrels become active in late March and early April
Look for tomato hornworms to be active in April. They attack grapes as well as tomatoes.
Grape fleabeetles may appear in mid April and eat holes in the leaves of grape leaves which appear as holes in the leaves. To the left is grape fleabeetle damage.
Watch for early damage to peaches and nectarine new shoots by peach twig borer. Treat with Bt or spinosad
New transplants, protect from cutworms with Bt or spinosad