There isn't enough information to suggest a probable cause based on what we actually know about the plant's recent care, but based only on the odds, a recent change in light from brighter to dimmer and/or over-watering in the not too distant past would be the likely cause(s), either individually or collectively. Al

Ken, Thanks for your quick response. Yes we did have a cold snap but 35 feet near the tree is another Yoshino tree. It's leaves are large and looking very healthy. I will send you a picture shortly. Iris ===>> i have 5 acres.. across such.. i have many forsythia ... frost can hit only one.. all.. some here.. some there ... there is no predictability to mother nature.. and her cruel sense of humor... it simply doenst matter ... what happened to one tree.. as compared to another.. i suppose.. its part of the base definition of micro climate... varying.. even across your small space ... it took me a long time to understand that ... ken

Rosco_P, First, I love the name you used! Second, you are welcome. I really enjoyed taking the class it did help explain much to me as well regarding coloration of plants. And now I can pass on what I have learned.

Here's a good description of birthmarking that I got from an AVAVS article. (I've included the link to the entire article below it if you want to read more. It's all about variegated foliage.) Birthmarks This isn’t a form of variegation in foliage but simply a birthmark. It’s a genetic condition that can be found on the underside of leaves. An easy example is to notice that the underside of silver under sided leaf exhibits red staining or markings. This is often found in multicolored blooming varieties. By nature it states genetically instability, hybridizers usually set these plants apart for future hybridizations programs. It usually makes the prettiest plant (but may not always bloom or grow to specifications) as more color in the leaves usually means more color in the blooms also. http://www.avavs.com/varifs.pdf I think what we can gather from this is that Laura's Little Kunzite is exhibiting genetic instability. Now, I've not grown this variety and I don't know it this is common in this plant, but AV's do some very wonderful and interesting things when they make these changes (sporting.) Of course, it can also be very annoying if you liked the variety the way it was and wanted it to stay that way, LOL. But I'd keep an eye on this one and see what it decides to become. It is very interesting!