Help me save my hollies!
I received these holly bushes (species unknown) from a friend who was transplanting and moving things around in her own garden. I planted them one week ago today. They were beautiful and vibrant (with light green new growth growing on top) when we planted them. After 2 days of heat, and 5 days of rain, they now look like this AND I've noticed "white somethings" on the leaves in addition to the large black areas. I'd love any advice on saving them! Thank you!
Your hollies are trying to establish themselves. All this rain is not helping. Make sure mulch is no thicker than several inches and away from the base of the shrubs. Make sure they are not planted too deeply. Take a look at our website http://extension.umd.edu/hgic/plants/planted-too-deeply-trees-and-shrubs
Also, we notice a sucking insect on the leaf undersides called cottony camellia scale. It produces a honeydew as they feed which promotes a black sooty mold on the foliage. Take a look at our website for photos and control information. You can spray with a summer rate of horticultural oil but you will have to get good coverage on top and bottom of leaves. Crawlers begin to appear in mid-June and summer on the leaves. You can wrap some of the branches with double sided sticky tape to monitor before spraying. Monitor the plants this growing season. http://extension.umd.edu/hgic/cottony-camellia-scale-shrubs
Before you spray it would be a good idea to thin the holly shrubs to let in more light, air circulation, and this will make it easier for the spray to contact the upper and lower leaves. They are too thick for the spray to penetrate. You have to get good coverage for control. Go inside the shrub and thin do not just head them back. Thin and remove any dead foliage/ branches in dry weather only before you spray.
Thanks so much! Should I be concerned this will spread to other plants in my garden or do they only infect hollies? If I decide to dig them up after unsuccessful efforts should I be concerned the soil is contaminated?
Some other host plants that can be susceptible to cottony camellia scale are holly, camellia, yew, and euonymus. If you decide to remove them, the soil will not be contaminated. There is one generation a year and immatures overwinter on bark or leaves.