I recently asked a similar question on what is a good way to prevent insects. I read that Bayer Tree & Shrub is not intended for indoor use or for potted plants (mostly though, it is DEFINITELY not for indoor use).

From what I read, I think Neem Oil is the way to go. I think you use it every 10 days (in a spray bottle, diluted - I think it's 1 tsp per quart. Some people also add a few drops of dish soap). Make sure you get a good brand that is 100% neem oil (I heard Dyna Grow is good). Also, make sure you don't apply it on hot days or in bright sun, as leaf burn may occur.

Neem oil is supposedly good for both a "slow" cure for bugs (can take between 3 and 14 days to kill them) and also as a preventative. When you spray the foliage, make sure you spray the undersides of the leaves as well.

Hope that helps,
Gabi

Systemics are a pretty heavy duty thing to use, I've done it w/ something called Marathon, which is now no longer available for amateur gardners. Also care needs to be taken to follow the directions exactly, which many folks don't do. I'd stay away from them altogether.

I'm unfamiliar w/ other remedies, but have heard good things abt Neem Oil as Gabi suggested or even Safer's Soap.

I'll chime in on the benefits of neem oil. I have occasional aphid and thrip problems that I keep under control with neem oil and I was even able to get rid of a chronic mealy bug infestation on a Clivia using a combination of neem and alcohol.

Neem oil has three ways of controlling pests. It smothers them when applied, it prevents many pests from maturing into adults and it works as an antifeedent (it coats the leaves and makes them unpalatable). It has a long history of use in human remedies and cosmetics and is quite safe for us to use. If you have pets or kids, it's ideal. The only bad thing about it is that it stinks!

I spray once a month and it keeps things under control.

BP

Bonnie,

Do you spray monthly on indoor plants or outdoor plants? I heard the smell is HORRIBLE and lasts quite some time if you spray it indoors.

Gabi

I only spray my indoor plants - some of them summer outside and they don't get sprayed during that time. I spray them before they come in. If, during the winter, the temperature is higher than 5C (? in F - maybe 40?) outside, I'll haul them out for long enough to spray and have it dry, then I haul them back inside. If it's too cold I haul them all into the bathroom, open a window and spray in the tub.

I will often stretch the spray times in the winter to six to eight weeks. As long as I don't have any active outbreaks and am just using it as a preventative, it still keeps the bugs under control.

Once the spray has dried most of the smell dissipates. I can still smell it a bit if I stick my nose right up to the plants, but after a couple of days even that smell has pretty well gone. I usually burn a scented candle for a day or two, and that covers the smell - guests entering my place have been unable to smell the neem oil.

I have been told by some plant nuts that they don't mind the smell, so it seems that it's not bad for everyone. I find it smells like rotten onions.

I consider the smell to be worth it - I will not use systemics because most of them are proven or suspected carcinogens or endocrine disrupters. Other people are comfortable with that risk, and prefer that to a bad smell for a few days. It's a personal choice :-)

BP

Yes, I've heard the "rotten onion" description of the smell :)
Thanks for the info on how you do it. Very helpful. I haven't decided yet if I'll be using it indoors. I was planning on using it for when I put my plants outdoors, but if the smell doesn't bother me that much I might use it indoors on an infrequent basis. I'd rather have to deal with a bad smell for a couple of days than a bug infestation!

Gabi

I've used all of the above. Neem oil works, to a point. It will not knock out a major whitefly infestation in a plant room crammed full of tropical hibiscus. It will keep minor whiteflies, aphids, mites, etc., under control during the winter if applied frequently enough. It does smell kind of oniony, but I like onions so it doesn't bother me much.

I was not aware that Marathon is no longer available for amateur gardeners. It is hard to find. It comes in a spray form and in granules that you dump on the soil. I found a couple of online vendors selling Marathon online. The granules are even harder to find online, but I like them because they are much less messy than sprays (easy to do indoors in the winter). The granules are not cheap (4 or 5 lb. jug for about $120, but should last me for years and years). I only use them if I see a severe infestation starting up.

Bayer also makes a product called Rose & Flower spray that has the same chemical in it as the Tree & Shrub and the Marathon. You can use the spray IF you drag the plants outdoors (in the shade), spray, let dry completely, then bring back in. Not very practical during a cold winter. But readily available at just about any place that sells garden stuff, and about $10 a bottle.