Dealing with reversion

Variegated plants can add visual appeal to borders, after all foliage is usually longer lasting than flowers. There are many reasons why plants produce variegated foliage, one reason could be virus infection and another is that the plant is a chimera. Chimeras exist in plants and animals and they are genetic oddities, two organisms with a different genetic make up coexisting as one entity. With variegated chimera plants there are two plants coexisting, one green and with a different colour-usually yellow or white. The yellow or white plant cannot photosynthesise (make its own food from sunlight) and so must live as a parasite on the green one. The plant would love to rid itself of the parasite, we would not as the combination of the two plants gives it its attractive variegation.

Once in a while these Siamese twin  plants become separated and a pure green or pure white or yellow shoot appears. White or yellow shoots are not a problem, it is the pure green ones that need treatment as without the burden of the white or yellow plant, the shoot is able to grow away strongly and eventually the variegation is lost. Some variegations are stable, others are not. The variegated Norway maple, Acer platanoides 'Drummondii' is vary prone to producing pure green shoots as are many hollies such as Ilex x alterclerensis 'Lawsoniana'.

Green shoots must be removed as soon as they appear and the trick is to remove every last trace of them, leaving a stub will encourage regrowth of multiple green shoots. Cut back into variegated growth and bear on mind that pruning cuts are often the site of new green shoots. It is a continual struggle with some variegated plants and I sometimes question on badly reverted plants if it is worth the effort.

Above is a picture taken of Lonicera nitida 'Silver Beauty' - a shrub very prone to reversion. The pure green shoots have larger leaves and are growing more strongly than the variegated ones. The green shoots will need to be removed quickly if the plant is to retain its variegation.

Holly (Ilex) starting to revert