The shrub forum's pretty active, and the people there seem to really know their stuff - just like the perennials forum participants. I'll put money down that if you post there, you'll get some responses right away. Anyway, since you asked here ...

I don't grow loropetalum, as it's not hardy here (yet!) but I've read that it likes afternoon shade. Some shade might help it hold the color longer into the season.

But, lots of purple-leaved plants lose their great, early foliage color as summer progresses. I have the same problem with cotinus, purple smokebush - it's still attractive, but not the gorgeous early color.

You might want to check the plants at your local nursery in late summer instead of spring, to see if they're holding the color you like, because it's possible that some cultivars are better in this way than others.

Okay. I didn't take botany, and now it's going to show. Rb, I think you are saying that our intense heat is the primary culprit, but are you saying that Nitrogen and POtassium deprivation would cause more dark pigment, or that more of these elements would increase it? And what about Magnesium? More will increase the darker pigment? I wouldn't know how to take N and K out, but I assume that Magnesium could be added. Your statement about drought might be telling. I have an irrigation system, the shrubs are near the lawn, and my husband insists on having emerald green grass, so we run it alot. Hmmmn, his green grass or my purple shrubs....this could be interesting.

It seems like we ought to be able to influence leaf color if the greenhouses and nurseries can.

I've grown purple-leafed Loropetalum in the Houston (TX) area and the color holds well through the growing season. So I doubt that heat is the culprit if greening occurs.

It's likely related most to the variety grown, or possibly soil conditions. I also don't think that nurseries are intentionally manipulating leaf color.

If your Loropetalums are adjacent to the lawn, they are probably receiving large doses of Nitrogen & Potassium due to runoff during rainfall or when the grass is watered. Lawn fertilizer usually has high concentrations of those elements to produce vigorous green foliage and a supportive root system.
Guess there isn't much you can do to reduce the chemicals, if green grass is more desirable. Lime added to the lawn probably won't have much effect on the plants, as they prefer a slightly acidic to neutral pH anyway.
I have never fertilized my two cultivars, 'Ruby' & 'Plum Delight' and seldom water them. Addition of compost top dressing is the only supplemental nutrients received and they retain their purple color all summer.
That being the case, they are slow to increase in size, but I would like to keep them rather small, as long as possible.
Sorry couldn't be more helpful, but I guess there isn't much you can do, given the circumstances.
Rb

Thanks for all the information, rb. You gave it alot of thought and I really do appreciate it. As it happens I have both PlumDelight and Ruby. PlumDelight has more color than Ruby, and you're right, it is further from the grass. I will definitely forego the annual fertilizing this year.

Hello,
I thought Lorapetalum is an evergreen Plant, mine lost its leaves during the winter. Mine was planted about eight months ago. Are these an evergreen plants? If yes, why did mine loose its leaves?

They are evergreen, but I have noticed in severe winters in our zone that they can lose their leaves. You don't say what zone you live in, but if you're north of me, that could be one explanation.

Hello again,

Thanks for your reply regarding my Loropetalum that loses its leaves during winter, I live in South East of North Carolina, I am not sure of the Zone ( I am new to gardening). Our winter is usually mild with few days of frost. Do you think the frost is the reason, or because my plant was not established prior to winter? Thanks

A friend had the same problem with the leaves of her Loropetalum 'Zhuzhou Fuschia' turning green. The owner of the nursery where she bought the shrubs suggested a general purpose fertilizer. It didn't really make sense to me why that would help, but it did the job - in a few weeks the leaves reverted back to their lovely maroon color. Of course, it could be a coincidence......

adykt, the fertilizer problably worked because it created a flush of new growth, which is purple.