Browning plants - Ask Extension
This happened last year as well. Starts out green and healthy then begins to brown systemically.
Knowledgebase
Browning plants #807742
Asked August 23, 2022, 6:31 PM EDT
This happened last year as well. Starts out green and healthy then begins to brown systemically.
Montgomery County Ohio
Expert Response
Hi Lynne, sorry this has taken so long but I just got the Email. Someone else didn't respond so they sent it to me. The plant as near as I can tell is Obedient plant or Physostegia. It has a pink bloom when it is ready to bloom.
The leaves and stems of the plant show a dull reddish-brown color. You can be the plant detective and take a stem with the reddish leaves inside and whack the stem onto a sheet of white typing paper. If something falls off and you take your finger and rub or smear it, you usually get a reddish streak. That is the fluid from the spider mites that are sucking the juices from the plant. Spider mites are difficult to control because they do not respond to normal insecticides (they aren't insects, they are mites, which is different). They take special insecticides that the homeowner usually can't get. So, there is an alternative. You can get your hose out and spray with a vigorous stream all the foliage of the plants. You will have to do this almost every day. The action is that you knock them off with the strong stream of water. The other action is that the moisture from spraying will cause them to swell up and burst! This is an old-time remedy that greenhouse growers used to keep spider mites under control. It works to some extent but not perfect. Hope this helps. Don
The leaves and stems of the plant show a dull reddish-brown color. You can be the plant detective and take a stem with the reddish leaves inside and whack the stem onto a sheet of white typing paper. If something falls off and you take your finger and rub or smear it, you usually get a reddish streak. That is the fluid from the spider mites that are sucking the juices from the plant. Spider mites are difficult to control because they do not respond to normal insecticides (they aren't insects, they are mites, which is different). They take special insecticides that the homeowner usually can't get. So, there is an alternative. You can get your hose out and spray with a vigorous stream all the foliage of the plants. You will have to do this almost every day. The action is that you knock them off with the strong stream of water. The other action is that the moisture from spraying will cause them to swell up and burst! This is an old-time remedy that greenhouse growers used to keep spider mites under control. It works to some extent but not perfect. Hope this helps. Don
Hi again. Here is a link to controlling spider mites outside:https://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/insects/mites/spider-mites-outdoors
Most of the miticides are no longer available to the homeowner. Your best bet is to use the strong spray of water especially on the undersides of the leaves. You can find the horticultural oils in some stores, but you have to watch the temperature as they can burn the leaves. Horticultural soaps will also burn if the temperature is too high. I would not use a systemic product applied to the roots because it would be taken to all parts of the plant and would probably not be good for bees visiting the flowers. Hope this helps you. Don
Most of the miticides are no longer available to the homeowner. Your best bet is to use the strong spray of water especially on the undersides of the leaves. You can find the horticultural oils in some stores, but you have to watch the temperature as they can burn the leaves. Horticultural soaps will also burn if the temperature is too high. I would not use a systemic product applied to the roots because it would be taken to all parts of the plant and would probably not be good for bees visiting the flowers. Hope this helps you. Don
