I received 4 "cold Hardy" trees in mid may that I'm assuming are mexicola grandes. I potted them in 4-5 gal containers with sand, perilite, cheap bark dominate potting soil and some pro-mix potting soil. They are about three feet tall now and put out a new flush of growth three wks ago. The new growth is a much lighter than the older leaves and some have yellowing veins. I've gradually moved the trees where they now receive sun from 8am-1230. There have been white flies for a little over a wk but are controlled for now. Any help diagnosing this and any other tips would be appreciated. There seems to be a lot of contradictory advice on the web. Thanks again