LOS ANGELES—With spider plant, croton, pothos, dracaena and the various ficus, variegated foliage seems to be very popular among house plants. Remember the wildly colorful variegations of coleus when it was a popular houseplant in the 1970's? Variegation is most commonly white or some sort of yellow; yet can be just about any color.
Holly olive looks sharp like English holly, but has the advantage of slightly blunted foliar spines.
In the landscape, variegated shade tolerant plants brighten shady spots even without bloom. Variegated acanthus, Japanese aralia, andromeda, hydrangea, aucuba and angels' trumpet show up nicely, especially when they can contrast with the darker green of other plants; although andromeda and hydrangea do not bloom as well in darker shade. Variegated periwinkle and English ivy are nice ground covers, (but potentially invasive).
Variegated trees, like tulip tree and certain maples, stay smaller than their unvariegated relatives, so can be proportionate to large atriums that could use their brighter foliage. Some of the variegated pittosporums likewise function like the unvariegated forms used for informal hedges, but work better in tighter spots.
Even if there is no need to brighten areas that are already sunny, variegated holly, lily-of-the-Nile, bougainvillea, pampas grass and silverberry add nice contrast where there is an abundance of rich green foliage. (However, some people who grow variegated pampas grass are not too impressed by it.) New Zealand flax presently happens to be one of the most popular variegated perennials, with many different personalities of color to choose from. Variegated varieties of several specie of agave and yucca are striking big perennials for the sunniest and even inhospitably hot spots, as long as they are kept at a safe distance. (Many have dangerous spines and teeth!)
Some variegated plants, particularly New Zealand flax, andromeda, Pittosporum tobira and the various maples, try to produce unvariegated mutant growth that grows faster and bigger, and overwhelms the desirable variegated parts. It is therefore important to watch for and prune out unvariegated growth as it appears. For New Zealand flax, this involves diligent digging and splitting to removed unvariegated shoots from the variegated parent plants.
foliage of the week: holly olive
If the foliar spines (teeth on the margins of the leaves) of English holly are too nasty, holly olive, Osmanthus heterophyllus, might be a more docile option. It lacks the occasional bright red berries and the very glossy finish on the leaves, but is much easier to handle than real holly is, since the spines are not nearly as sharp. If you look closely, you can see that the one to two and a half inch long leaves have opposite arrangement (are in opposing pairs along the stems) instead of alternate arrangement (are single along the stems) like those of holly.
The more popular varieties of holly olive have some sort of variegation of white or gold. Variegation can be spots, blotches or more refined margins. Most of the modern variegated varieties prefer to stay less than six feet tall. The old fashioned unvariegated holly olive can get more than twenty feet tall when very old, but the upper foliage lacks the distinctive foliar spines of lower foliage. The tiny and mostly unnoticed flowers are pleasantly fragrant.