Pecan trees produce new leaves later than most other nut, fruit or ornamental trees. But once the leaves start to bud, they provide a strong indication that flowers will soon follow, followed by green fruits that ripen into tasty nuts.
In warmer climates such as in Texas or the Deep South, pecan trees may start budding in March. In most other locations, the first leaf buds do not appear until April or even as late as May.
Pecan tree leaves eventually grow up to 12 to 20 inches in length during the growing season, and resemble fern leaves. Each leaf contains 11 to 17 leaflets. Once the leaves appear, small yellow flowers bloom next, helping to pollinate the tree so that it produces fruit if the tree is old enough.
Once the first leaf buds reach about 2 inches in length and look ready to split, you need to watch for problem insects. If you see pests on the foliage, pesticide spraying should start once the first buds leaf. The spray helps keep harmful insects from defoliating the tree.