

I should never buy plants from a catalog again. I need to keep repeating this mantra. Never buy plants from a catalog again. A while back I wrote about the mail order coneflowers I received. I planted them and snails immediately mowed them down. Now this isn’t the catalog company’s fault but I never have good luck with mail order plants.

I decided to put some of the coneflowers in larger pots, instead of the potlets they were shipped in, until they were big enough to fend for themselves. They grew bigger but now they have
white flies. I know I should probably just throw them out but I have so much time and energy invested in them that I’m going to try to get rid of the flies first.
Besides I read that throwing out the infested plant doesn’t cure the problem. Although this was information from an online store trying to sell chemical remedies.
In order to get rid of them, I needed to learn a little about these tiny tenacious creatures.
It seems that there are two main types of white flies: citrus and greenhouse.
Citrus can be found on just about any plant and greenhouse white flies are mostly found in greenhouses.
The Citrus type are harder to get rid of because they hang around all year long. The Greenhouse type are a little easier because they go dormant as winter sets in.
I hope I have the greenhouse kind, but I don’t know.
Both types develop from eggs and go through a series of instars (a phase between two periods of molting). Once fully developed, the adult white flies will lay eggs in less than a week. They lay their eggs on the undersides of leaves in hard-to-see locations.
Once the young emerge they start eating—and the damage begins.

White flies have piercing mouthparts that allow them to suck the sap out of plants. This causes leaf damage, sap drainage, which in turn causes fungus, bacteria and heat stress. On top of all this, white flies excret
honeydew, which lures other nuisance insects onto the host plant. Some of these insects protect the white flies and harvest the honeydew. The honeydew also promotes growth of
sooty mold.
White flies are very prolific and will make their home on any plant that has plenty of sap.
I read that you can control white flies before they start by setting out white fly traps. White fly traps are bright yellow glue traps, which attract the white flies.
They catch the white flies as well as serve as an alarm system to alert you to white fly activity.
You are supposed to place them near any plant that you want to protect. This doesn’t seem feasible to me since I want to protect all my plants and my yard is about an acre in size. That’s a lot of little yellow sticky strips.
I can just see my dogs now walking around with little pieces of paper stuck to their paws and noses. No worky.
I was looking into a safe non-chemical remedy for the stupid flies and insecticidal soap came up. It is really the only safe method beside natural predators.
Insecticidal soap works by preventing adults from flying. It stops colonies from laying more eggs and it suffocates some of the flies. I guess insecticidal soap is a chemical but it’s safe for the plant, animals, kids, adults, aliens, and teenagers. So I am considering this option.
Then I read in my
Master Gardener Handbook that chemical methods are not effective.
They recommend natural predators. The best being
Encarsia formosa, a teeny tiny little wasp that loves to chow down on white flies. Yeah for parasitic wasps. (I happen to have one named after me.)
You can have some success ridding your plants of white flies by using praying mantises, but they don’t do nearly as good a job as E. formosa.
After all this chit chat about Encarsia, I decided to conduct another experiment, mostly out of laziness and tight-waddedness. I made my own soap spray last year that seemed to work wonders on wooly aphids. So I made another batch for the pesky white flies.
I make it out of 1 part
Dr. Bronner’s Pure-Castile Soap and 10 parts water (or thereabout). I’ve been using it for two days now and it seems to be working.

I will keep you posted.
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The white flys probably did come in on your mail order plants. I'd be contacting the company and bitching long and loud about it as they will infest everything around them. The good news is they are probably the greenhouse variety. Still... your plants should have been pest free. Good luck with the spray!
Posted by: Sally | June 22, 2007 at 05:18 AM
We're throwing out a few flats worth of pansies because white flies attacked with a vengeance. After using Neem and a stronger insecticide we still lost the battle. Do you have to throw out the huge pots of dirt, too, or can it be salvaged with other new plantings? We spent a small fortune on potting soil for all these monstrous pots on our screened porch and I hate to throw it all away if it's not necessary. I was kind of hoping that once the plants are gone I could treat the dirt, too, and re-use?????
Posted by: kimberly | April 22, 2008 at 04:48 PM
Kimberly,
Sorry it has taken so long for me to get back to you.
I don't know what to say about the potting soil. If it were me I would probably take the first few inches off the soil at least.
Posted by: chigiy | May 20, 2008 at 03:50 PM
Whiteflies are becoming a menace in California. Here's how you can use organic sticky traps to control whiteflies:
http://californiagardening.blogspot.com/2009/10/sticky-aphid-whitefly-trap-seabright.html
Posted by: Kartik | October 22, 2009 at 01:25 PM
Twice now, I've bought Miraclegrow potting soil, only to discover it is infested with white flies!
Maybe it was sterile when it arrived at the store, but it did not remain so.
Now I don't know what to use. After having had some seed from lilly pod sprout(success!!), I used this soil but am worried.
Has anybody else had a problem with this potting soil?
Posted by: Judy | July 31, 2010 at 11:05 AM
Hi Judy,
I have only used Miracle Grow potting soil once before and I didn't have the problem. Did you take it back to the store and alert them? If you didn't, you should. It wont take the white flies away but maybe it will get your money back.
White flies are a bummer. They don't like the sun very much and they thrive in crowded conditions.
Knowing what I know now it is probably best just to toss the infested material.
Good luck!
Posted by: chigiy | July 31, 2010 at 11:37 AM
DO NOT USE DR. BRONNER'S SOAP ON THEM!!! I have found the answer to whiteflies - - I've been battling them for a few years. I got the idea from googling natural remedies to whiteflies - I found the Bug Blaster, which works with water. I use my own version - I use the CONE setting on a garden hose and although they're not gone, they're much less! Good luck!
Posted by: anon | June 19, 2012 at 07:11 PM
Perfect solution. Buy a bar of Unilever sunlight bar soap. Grate about a teaspoon full into a pot with a bout I litre or I quart Of tap water. Bring to a slight boil and remove and let cool. Stir well. Once cool place solution in a good atomizing type spray bottle. Spray the affected plants from the bottom up. Repeat twice in two week intervals.
You will be amazed. If indoors put a sheet down beneath the plant to protect from overspray. You will see the little critters falling onto the sheet
Posted by: Tim Curtis | March 29, 2013 at 09:29 AM
Anon and Tim,
Thank you so much for these solutions.
They both sound great and I will try both.
Take care,
Posted by: chigiy Binell | April 01, 2013 at 11:23 AM
After battling white flies for years here in San Francisco, CA and trying everything including neem oil, soapy water, poison...on a whim last week I decided to try a soapy solution of Dr. Bronner’s Peppermint Pure-Castile Soap and water, well, it is working I haven't seen any white flies since I started using the solution and my apple tree is finally looking healthy. It really is worth a try, but like head lice you have to keep checking for them because they can multiple so rapidly.
Posted by: Kelly | April 26, 2013 at 08:23 AM
Thanks Kelly,
You are correct, you have to continue to be vigilant and keep looking for an outbreak of the pesky bugs. My white fly problem has all but disappeared but I keep an watchful eye out for them.
Posted by: chigiy Binell | April 26, 2013 at 09:06 AM