The green colour of leaves is due to the presence of chlorophyll, the all-important green pigment which traps sunlight energy for photosynthesis - this energy-requiring process, whereby carbon dioxide from the air and water is used to produce carbohydrate (glucose), is directly or indirectly essential for all life on earth.
Leaves may also contain orange-yellow carotene, yellow xanthophylls and red-purple anthocyanin pigments, but they are normally masked by the green chlorophyll. In many deciduous plants chlorophyll is broken down prior to the leaves falling and other pigments become visible - giving leaves their beautiful autumn colours.
Variegated fuchsias have green leaves that are streaked, marbled or patterned with yellow, cream, white, golden or, if anthocyanins are present, reddish purple colours.
Variegation is due to a genetic mutation in some mother cells in the growth tip (meristem). The result is that two or more cell populations are found in the same leaf or branch (chimera).
If the cells developing from such a mutated mother cell are unable to make green chlorophyll due to the change in the genetic code, the underlying plant pigments show up or if no pigment is present the affected areas appear white and the leaf is variegated. Such leaves do have some green chlorophyll; totally white leaves do not survive as photosynthesis is not possible. The degree of variegation varies from leaf to leaf and from plant to plant.
In fuchsias the cause of the mutation and the resulting variegation is mostly unknown, it often appears spontaneously and is called ‘sporting’. This term is also used if a branch with different coloured flowers appears on a cultivar. Mutation may be caused by a variety of factors such as irradiation, chemicals and virus infections, all of which change the genetic code which in turn may result in an inability to produce chlorophyll and thus variegation.
Variegated fuchsias do not grow true from seeds, and propagation is done by taking cuttings from the variegated cultivar or the sporting branch (cloning). Hybridising with variegated fuchsias does not usually produce hybrids with variegated leaves.
Variegated leaves with their patchy absence of chlorophyll are at a disadvantage as photosynthesis is less efficient, they tend to grow slower and do best in bright light. Variegation is rare in nature since variegated plants are weaker and die out (survival of the fittest).
The most striking colours are seen in young leaves e.g. Autumnale. For show purposes frequent pinching is done up to 3-4 weeks before the show in order to have as much colourful young growth present as possible. Flowers are not required for the variegated class.
A branch of a variegated cultivar may revert to the normal all-green colour with energy-capturing chlorophyll all over. The green leaves are larger and will eventually overgrow the variegated branches – often seen in Dawn Fantasia. For Show purposes all reverted green branches should be removed or the variegated appearance will be degraded and penalised in shows.
Feeding high N and/or Magnesium to a green/yellow/white variegated cultivar will bring out more green and should be avoided. Interestingly giving high Mg to predominantly reddish/cream leaved cultivars such as Firecracker (sport of Thalia) brings out the red colours more distinctly.
Below are four examples of fuchsias with variegated foliage:
Other fuchsias with variegated foliage are Golden Marinka (sport of Marinka), Autumnale, Sunray, Sharpitor, variegated Lottie Hobby an Encliandra, and F. magellanica aurora.
Cultivars with light green or gold foliage with red veins and ribs are uni-coloured and, though attractive, are not considered variegated.