|In early Spring I purchased a Monrovia Flower Carpet Yellow Groundcover Rose. It stands about 4 feet tall , single stem, bush top, and was nicely in bloom until the last few days. Now, leaves are turning yellow and falling off. Our wx has been quite hot and humid recently. I've kept the plant containerized, transferred into a larger container after purchase, and have the container set in the ground so it can be pulled out in winter. I keep it well watered and have used the Bayer Rose systemic granule feeder.
|Based on your description I suspect it may be overwatered. Roses need an evenly moist yet well drained soil. This means not saturated or sopping wet. Sometimes when you sink a container into the ground the hole works like a sump and collects extra water in the bottom. This means the potting mix is sitting in water and absorbing it like a sponge and stays constantly wet. Another possibly soil problem is if the new soilyou used when you repotted it is not draining at the same rate as the original potting mix -- most soilless mixes draing quickly. If the roots are overly wet they may rot, one of the signs of this is foliage problems.
Another possibility is that a fungal infection such as black spot might be starting. I would suggest you work with your retailer to try to determine the specific cause of the problem and then knowing that, decide how to proceed. I hope it is nothing too serious. Good luck with your tree rose.