Dumb Cane Possible Disease

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Dumb Cane Possible Disease

Post by luckybny » Wed Jul 30, 2014 3:34 pm


I have a dumb cane plant that is beautiful, getting large and I was told it appears quite old. This is the because of the large stems that now fall down next to the container. I’ve had it for 2 years and it’s in a container in my kitchen (medium light). I’ve been consistent with watering it and it’s always been in the same place. It’s been very healthy until recently. It seems to have 2 possible issues: 1) brown spots on some stems that look like warts. When I scratch them off it smells funny like an onion but then again anytime I have to remove a dying leaf it smells the same. Maybe the odor is just the nature of the plant. 2) 3 of the large stems have turned lighter green and getting soft. One broke off the other day because I was bending it slightly to see how soft it was becoming. I have been lax in giving the plant fertilizer and may have slacked in giving it enough water the last month since it’s been very hot. I’m just wondering if the plant can be saved. I did give it fertilizer last night.

Any advice would be greatly appreciated.

Melanie Small
Rochester, NY

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Re: Dumb Cane Possible Disease

Post by lorijones » Fri Aug 08, 2014 2:09 pm

The brown "warts" on the stem may be scale insects. If they are slightly hard and scrape off with your fingernail, that's probably what it is. You can control them with a horticultural oil spray such as Bonide All Seasons Oil or PrueSpray Green.
If your Dieffenbachia is very tall and seems to be flopping over. it might be a good idea to cut it back and let it regrow from the cut stems. Wear gloves when you do this and be careful not to get the sap on your skin or in your mouth as it is toxic. If the tops you cut off are healthy, you can root them to create new plants.
During the spring and summer, keep your plant well watered. The soil should be kept moist but not wet. Over watering can lead to stem and root rot. You can feed it with a houseplant fertilizer (use it at half strength) about once every 3 or 4 weeks.

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