Description: The olive’s leaves can be seen from a distance by their silvery sheen. Autumn olive has green on top and silver underneath, whereas Russian olive is entirely silver. All leaves appear scaled when up close. Young stems are silvery with brownish or orange scales that make them appear speckled. Some stems may bear large thorns. They have fragrant, yellow flowers in the spring and develop speckled red berries in the fall.
Impact: Both olives alter the chemistry of the soil where they grow, changing the kinds of plants that can enter and grow in the community, and helping the olives to persist. They also shade out younger trees by retaining their leaves into late fall. The leaves are undesirable by herbivores, including deer, and although the fruits are eaten by wildlife, they provide little nutrition.
Management: Since the tree spreads widely by seed, removing the plants before they fruit will help limit their spread. Cutting or mowing without herbicidal treatment, however, will only encourage regrowth in autumn and Russian olives. Paint cut stems when possible. Foliar sprays can be used in early spring, when the plant is leafing, or in late fall to minimize damage to native vegetation.