Reversion and Sports
Variegated trees and shrubs usually originate from mutations or sports, and some variegated shrubs such as Euonymus Emerald 'n Gold can revert back to its original green colour.
This occurs when the reverted shoots contain higher levels of chlorophyll, which makes the reverted shoots more vigorous than the variegated shoots.
Cut out the affected shoots as soon as they are noticed by cutting back into wood containing variegated foliage, even if it means removing the entire shoot.
Euonymus Emerald 'n Gold
A sport arises when a genetic mutation in part of a plant causes the plant to produce new characteristics such as a different leaf or flower.
Sometimes this mutation has desirable features that lead to new cultivars being established.
Most sports will not come true from seed, therefore new stock is generally produced vegetatively (cuttings).
Some of these sports can be unstable and revert to their original form, so breeders and growers tend to cultivate them for a year or two before publicising them.