Give it more sun! Once it's been acclimated to the light, it needs full sun. It grows in e.g. Indonesia year round in much hotter and brighter conditions, though with a lot more humidity, so it's unlikely to be happy with 2 hrs/day.

Variegated plants are often a bit enigmatic. They need more light than their all green counterparts to maintain the same level of vitality, yet they will not tolerate as much light. Pigments (including chlorophyll) are largely lacking in the lighter portions of variegated leaves, and those pigments act as a sunscreen for your plant. The leaves of your plant will likely burn in full sun exposure, regardless of attempts at acclimation, while the all green species plant growing next to it would probably be fine.

"What did I do wrong?"

Variegated plants usually start life as a variegated branch or small growth on an otherwise green-leaved plant (sport/chimera). That growth is removed and the variegated cultivar is then vegetatively reproduced.

Since the pale parts of their leaves lack sufficient chlorophyll for efficient photosynthesis, variegated plants are often less vigorous than their plain green counterparts. Consequently, itÂs not surprising that if grown in deep shade or when starved, pot bound, drought or otherwise stressed, variegated foliage often shows a strong tendency to revert to green. Reversion is usually just a survival mechanism: when the going gets tough the plant has a better chance of survival with plain green leaves that are best able to make use of their ability to photosynthesise light. Occasionally variegations are simply unstable and may revert for no apparent reason.

Whatever the cause, once reversion starts it will usually continue unless you intervene. That means keeping a sharp eye for branches with plain green leaves. Remove these twigs or branches immediately, cutting them right back to the stem from which they are growing. Any delay could cause problems because the reversion tends to speed up as green leaves begin to outnumber the variegated ones.

Al

The Ficus already has more green leaves that the old variegated leaves. Should I cut all new green leaves and stems down to their origins from the old variegated stems and just leave the variegated ones to correct the problem?

What if the reversion is being caused by other cultural issues like light, e.g.? If you cut the plant back, you sacrifice it's development and may not correct the problem. It's kind of a judgment call, and how robustly the plant is growing now will be the main determining factor - you don't want to kill it in your attempt to retain the variegation ..... It also depends on where you are in CA (covers a LOT of latitude) and what your weather pattern is like - you can get away with much more in sunny/warm LA than foggy/cool SF. You should note your city or what major city you're near (or at least your USDA zone) in your user info.

Al

I'm in Southern California, in Orange County roughly between LA and San Diego, about 4 miles from the coast. If I try to minimize the greens by cutting some of it off and moving it from current location into full sun, will that help? The plant seems healthy enough to tolerate a severe pruning. The climate seems to be in a cooling trend working towards the fall. Ficus plants are a dime a dozen at the big box stores but I really am primarily interested in the variegation of this plant. Also, in my experience, Ficus plants seem to react with leaf fall when the lighting conditions are altered suddenly such as indoor to outdoor move, or shade to full sun change in exposure.

If the tree is robust and light/temperatures are favorable you can cut hard with impunity, except for the effect on development.

Just a note about Ficus leaf loss. When you move the plant from dim to bright (with proper acclimation), or from cool to warm (both within reason, of course), they reward you with increased growth and additional leaves - not leaf loss. When you reduce the light load, subject them to sudden chill, or over/under-water, you can expect leaf abscission. They are not particularly finicky about 'change' per se, but they DO react to a change in the wrong direction.

Al

Is the variegated ficus a root problem for foundations, etc., like they say the green leaf ficus is?

Probably - The aggressiveness of Ficus roots and their potential for damage varies by species, and there isn't anything specific enough about "variegated Ficus" to be able to say with certainty. The roots of some Ficus species, including benjamina, are so powerful they can cleave rocks, destroy concrete buildings or buckle roads, and are measured in fractions of kilometers or miles, as they extend underground in "search" of water (technically, plants don't really search for water or nutrients). Prolly not a good choice as a foundation planting .....

Al