Is there a practical way to get rid of aphids and white flies on squash plants?

Question

I have tried soap solution followed an hour later by water. Incomplete results, cumbersome. Any other suestions?

Answer 1

Sounds like you want to stay organic. First thing is the cause. Your fertilizer is too high in nitrogen, and though that makes what appears to be a big healthy leaf, that leaf is soft and tender and loved by aphids (and will also be disease prone). Use for your veggies either a balance like 10-10-10 with micro nutrients, but better yet is 5-10-5 or 10-20-10 etc with micros's. Watch the watering also, limit it to the earliest AM hour you can do it at. That keeps the leaf moisture time lengths to a minimum and helps avoid the next set of problems from a soft leaf and insect damage, expect disease like fungus and even viruses (no tobacco in the garden, wash hands if you smoke due to TMV).

Now to fix it. Know first of all that aphids are kind of opportunists. They are at the mercy of the wind but frequently overwinter in garden litter, and when they find something good, they stay. Aphids can be BORN PREGNANT, and now you can see the problem. One is not one, it is a colony. A number of things to try now that you have them. The soap you want to use is insecticidal soap which is different than plain soap. Plain soap and water blasting's do work but not well and water blasts hurt new leaf tissues. Use insecticidal soap every 2-3 days for 2 weeks. You can add Bt to the spray (Bacillus thuringiensis) about every other week for added kick that works very well for aphids and other pests (make sure you get the proper Bt as there are different forms, ask a garden ctr rep). If you want to incur the added cost then use Diatomacious earth, or crushed diatoms, after the soap dries and dusting it from bottom to top. What they are are diatom shells ground up, and those shells are silica; natural glass. The sharp edges cut the insects. A cheap dust to slow aphids down would be flour or baking powder (not soda).

To be organic but still effective, very effective, is the use of the insecticide, pyrethrin spray, if you have a real issue, but this stuff needs to be used with care and directions must be followed closely. If you are not sure or have never tried it ask for help. The old timers down the road will always be willing to talk garden, trust me in that, and generally will offer a hand when in need. This, as well as some other items can also harm the beneficial insects, so use with care, and use sparingly.

Other things? Aluminum foil 1 ft by 1 ft squares as a mulch/ ground cover work by confusing the bugs. They see sky blue reflected and keep flying. White will work a bit too. Bug brains seem color tuned so the different colors with very little green tells them "No food here!"
Sticky bands, petroleum jelly, or gooey sticky (non-toxic please) stuff painted on stems of plants keep the ants away that are attracted to the aphid sugar, and ants protect and herd the aphids, killing beneficials. Sticky traps help or the sticky might be scooped off and put on the stems. And also, aphid sugar gets a nasty black color from it rotting (fungus) and that is a problem. Aphids suck sap, and exude sugars.

Oil sprays, seaweed sprays, hot pepper sprays, ground-up aphids in a spray, garlic spray, coriander and anise spray, tomato leaf tea spray (made with a quart of tomato leaf steeped in boiling water (do not boil and do not accidentally eat!) and squeezed to make it strongest; refrigerate to keep but label it POISON) or mixtures of the above all have value.

Fall and spring clean-up is your best friend. It gets over wintering bugs and eggs out as well as disease carrying inoculum.

Keep weeds out. A garden with weeds or too tightly planted gives bugs an edge and slows your garden down with competition.

Trap crops like nasturtium planted away from garden edges (10-15 feet from your plants is the most) catch bugs before they get in as they love it, and also the flowers and leaves are edible and beautiful in a salad. DATE NIGHT HINT (nasturtium flowers in your salad; LOVE!!)

That about covers it. I checked the books I have to make sure I didn't miss anything or what not. Good luck.

Answer 2

You may want to try more powerful soap-based insecticides made by "Safer"; they take longer than poisons, but don't leave toxic residues. The aphids should be easy, but whiteflies next to impossible. Fortunately the whiteflies don't cause a lot of damage to the plant if you can keep their numbers under control by frequent washing of the plant.

Answer 3

Mix garlic with soft soap such as velvet soap mash the mix until it is liquid mix a little water and spray on the little buggers have tried this and it does work !