Insecticidal soap.
Follow the directions on the bottle.
You can find this product at Ace Hardware or a local nursery.

Whiteflies have destroyed the leaves on my roses this year. I've never seen them on roses before.

Ecopal, I don't know where in FL you reside, but down south here we have a relatively new invasive whitefly called the "gumbo limbo spiraling whitefly" (yes, that really is the name--Google it to learn about it). I have been fighting a losing battle for months with them--and I loathe them.

They don't kill the plant, but they severely weaken it. They lay their eggs in a spiral pattern on the underside of leaves, then when the eggs hatch, they feed on the underside of the foliage. In the places on the leaves where they feed, a fungus called "brown sooty mold" grows. My house has basically become a brown sooty mold farm--apparently, as unsightly as it is, it won't harm your plants either and goes away when (if??) the whiteflies go away.

Controlling them is difficult because if you've got them, chances are your neighbors do too. Where I live, every single plant around is covered with whiteflies and their eggs and that disgusting sticky resin. It's vile. Someone in the plumeria forum told me that if you mulch with worm castings, it acts as a systemic and drives them away in a week or two. Haven't gotten around to ordering them yet, so I can't say whether it worked for me.

Greg

Bayer has a systemic product for Fruits and vegetables that will take care of the white flies and another product for roses and flowers and another for trees. I love systemic. You get full coverage which is difficult to do with sprays.

I would be thrilled to use the Bayer systemics, but the problem is that those products are "2 in 1:" they have NPK in them, and the last thing my plants need is more chemical fertilizer. I wish they offered the product without--it's a shame.

The Fruit Citrus and Vegetable does not. The purpose of the fertilizer in the other products is to help draw the systemic into the plant. I just cut down on the fertilizer I use on my plants.

In California, we had terrible whiteflies on all hibiscus plants. The best way I found to get rid of them was just to spray them hard every day with a strong water nozzle. Good thing hibiscus is sturdy enough to handle that because I don't think my roses could've taken it.

There are many great links about this pest on solutionsforyourlife.com.

Just enter gumbo limbo spiraling whitefly in the search box.

Here is an excerpt from the link below:

On small trees, palms, and fruit trees ultra fine horticultural oil and
insecticidal soap can help control this pest, but 2 or more applications will
be necessary 7-10 days apart. These products are available at garden
centers and retail nurseries. Follow the label directions. Soaps and oils are
less destructive to beneficial insects than other contact insecticides.

Systemic insecticides are products that move through the vascular tissue
of the plants. Whiteflies are poisoned as they feed on the plant sap.
Contact insecticides, as the name implies, must make contact in order to
kill the insect. Contact products can also kill beneficial insects. Systemic
insecticides can provide longer term control than contact insecticides
particularly if the systemic insecticide is applied to the soil or trunk. For the
above reasons it is recommended that where possible it is preferable to
use systemic products.

Systemic insecticides applied to the soil take time to work. Expect the
product to start controlling the pest after about 1-2 weeks for small trees,
palms and shrubs, and up to a month for large trees, and palms. However,
systemic insecticides often last 9 to 12 months if applied to the soil.

Be aware that some trees naturally lose their leaves during the dry season
(late winter for gumbo limbo). Early spring is a good time to apply systemic
insecticides to the soil.

Here is a link that might be useful: Common questions about the gumbo limbo spiraling whitefly (Aleurodicus rugioperculatus)

For the past 4 or 5 years whiteflies have swarmed my garden in Biblical proportions, especially the tomato plants. After deciding to give up gardening here, a friend mentioned using worm tea. I purchased a bottle online, used 1/3 cup worm tea to 1 gallon chlorine free water, by spraying every three evenings on the underside of the tomato leaves. It took a few weeks, but gradually I noticed less and less whiteflies.... now, I have NONE! BTW..The worm tea is the only fertlizer I've used this year.
At first I was quite skeptical, but now and a firm beliver in using worm tea.

nancybhd

thanks for the wormtea tip. I gave up tomato plants for the last 1.5 years (except volunteers) because nothing removed the whiteflies (neem, soap suds, other organic sprays). I'm not willing to go non-organic.

They seem to be gone for now but I'm hoping to plant beans again (whiteflies LOVE bean leaves) so I'll keep this in mind. I have worm casting fertilizer to make the tea.

Denise

I had the same issue with my bell peppers so I manually cleaned each leaf of around 9 plants with a neem oil solution and a terricloth rag. So far, so good.

Denise,
I want to keept it organic, as well. That's why the worm tea solution appealed to me. It worked so well, I bought some worms and am now raising worms for their castings to make my own tea. It's nice to be able to grow veggies again! :o)

Can you elaborate on growing your own worms? and extracting the tea?

I wish I could get rid of my whiteflies too.. What if I wash the leaves or crush the eggs? Cause if I cut the leaves if my plants I think they'll none be left.

I hope that worm tea will work on mine. I dont want to cut the leaves with all the whiteflies on it, because there will be none left.