leaves of roses and verbena changing

Question

What would cause the leaves on my roses to change from the normal ovate shape to thin, claw-like leaves? Happens to verbena as well. Is this too much nitrogen? Our roses (different varieties) as well as our verbena and nandina have developed thread-like leaf growth and resultant stunting, even death in some cases. I’ve moved some to different locations and the problem seems to go away for a while but eventually returns as summer progresses. I’ve thought perhaps they are getting either too much or too little water, or too much nitrogen. I am about to dig up a verbena and examine the roots, then pot it in a low nitrogen potting mix. Thanks for the help. I can post photos if necessary.

Answer 1

In my area it is the intense rays of the sun and the strings of 90 degree and hotter days. They just cannot move enough water through their stems or canes to keep the foliage looking good. It is a very good idea to keep an eye on the soils moisture though, as with the heat and a wee bit of wind the moisture gets sucked out of the ground pretty quickly. If you can do something to create some shade for them during the hotter parts of the day, that will help big time. Things should get back to normal once the temps cool off some.