Question
I have had this plant for 2-3 months and I'm finding that there are tiny bugs (ones that look like fruit flies) in my apartment.  They seem to come from the barky cane.  How do I get rid of these pests?

Specifics about my plant: Dracaena massangeana cane or corn plant, pot size approx 12", located in low light, never repotted, no change in plant's environment.

Answer
Hi Linda,

Those are fungus gnats. Adult fungus gnats fly around and are an annoyance, but they are not harmful to people. Each gnat lives for about 5 days. The trick is to get rid of the next generation - the gnat larvae that live in the top layer of the soil. The larvae feed on decaying organic matter. Decaying pine bark in potting mixes and decaying plants roots feed the larvae.

They are often an indication that the soil is staying too moist. Try to keep the soil as dry as possible. For a corn plant that means allowing at least the top quarter of the soil to dry out in between waterings.

Remove all loose soil from the surface and put a light layer of coarse coir (coconut husk) or sand or diatomaceous earth on the soil surface. These substances have sharp edges that carve up the larvae. (Recent studies indicate that fine-textured peat moss also deters gnat larvae.)

Another safe technique is to place ?inch slices of raw potato on the surface of the soil. After a day or so, discard the slices along with the larvae inside. Repeat this until there are no more larvae in the potato.

For more serious infestations try Knock-Out Gnats to treat fungus gnats available from Gardens Alive for about $20. See http://www.gardensalive.com/item_display.asp?ProductNumber=1962

Detection trick: Add a little water to the soil and then look very closely for tiny fungus gnat larvae swimming in the water as it pools on the surface. You need good light and good eyes to see them. If you don't, then your plant is probably gnat free.

Please let me know if any of this is unclear or if you have any additional questions.

If this information has been helpful, please take the time to give me a rating and nomination.

  
Regards,
Will Creed, Interior Landscaper
Horticultural Help, NYC

You can E-mail me directly at: [email protected]

Visit my website at  www.HorticulturalHelp.com