Question
Hello there. I have a small greenhouse that has gotten a nasty ant infestation. I was wondering what insecticide would be the safest to use on and around my plants. I have mostly Nepenthes in there and some tropical Drosera. Also, what is the best way to heat a greenhouse? It's 8'x10'.

Answer
Hi Greg,

If the ants are the little sugar ants, bait is the best thing.  If you look in the insecticide section of a garden center you should see different kinds of "Ant traps" or liquid baits that you put on little paper tabs.  All of these use boric acid which is a very safe substance.  Since this is bait, it's of little consequence to the plants.

Heating your greenhouse will depend a bit on your situation.  If you want to go electric, nothing beats ceramic disc heaters.  These are a bit different than the cheap ceramic heaters seen at most big box stores.  Here's an example:  http://www.pelonis.com/discfurn.htm  I used one of these for 5+ years in my first 11'x12' greenhouse.  No other electric heater even compared in efficiency.  Just be sure to locate it so it can't get any water splashed on it.  If you heat electric, you'll need a propane heater for back-up in power outages.  You want the kind used for indoors such as these:  http://www.mrheater.com/productdetails_extended.asp?catid=41&id=24  If you want the best of both worlds direct vent gas heat is the way to go.  (We just got two of these units online for our greenhouses after a very close call last year with a power outage.)  They are a bit expensive, but work well and give you piece of mind.  Here's an example:  http://www.asapheat.com/orbiz2.htm


Good Growing!

Jeff Dallas
Sarracenia Northwest
http://www.cobraplant.com