Aphids 2; Cucumber & Melon 0

I planted 4 squares of my SFG that were nearest the house (about 5 feet away). The squares had a tomato, watermelon, cucumber and squash plant.  The aphids came and took over both the cucumber and watermelon plants just as the cucumbers started ripening.  Now the squash leaves are wilted with spots   The tomato plant has powdery mildew on a few leaves .  I remove the affected leaves, but it still comes back. I forgot how to load pictures, so no pictures attached.

Am I planting those vegetables in the wrong area? 

I bought a moisture meters to help me know when to water my plants.  That showed me that when it rains at an angle, the 2 rows of squares closest to the house do not get much rain, if any.  The SFG gets just over 6 hours of direct sun a day.

I have also learned that I don't have any beneficial insects in my yard.  Yet I can't buy them in Hawaii, so I need to start a flower garden to attract them.

My broccoli, daikon, carrots, lettuce, and spinach are doing fine in the 3rd and 4th rows from the house.

Any advice???

Nan, I also have about 6 squares that can't receive rain (we had a little this spring) so I had water those even when the rest were wet. As long as the plants have 6+ hours of daily sun, you can provide the water and they should be okay.

Aphids. I tried Bonner's Liquid peppermint soap (Audrey's idea) and water for the aphids. I would say it was about 90% effective in killing them. Then when I sprayed later with the hose, most of the rest washed off. I did it when the bees weren't out.

Milk or Neem solution work pretty good for powdery mildew. It would be great if you could post some photos to make sure you don't have something else going on.

Here are some of the leaves on plants that I discarded. 

First here is the cucumber plant



Next the watermelon plant





Next the tomato plant



And at last the squash plant. 





Help in conquering my problems are appreciated.

Nan, Have you tried the Bonner's liquid peppermint soap or the Neem oil solution?

You can't buy beneficial insects in Hawaii? That's weird -- when I lived there I saw ladybugs around and the occasional praying mantis too. Maybe they're both considered non-native? Anyway I just find that curious.

I had similar aphid infestation in my broccolini last year. I squished them by hand against the leaves. I also sprayed with a soap spray and with neem. I'm afraid nothing worked for more than a day or two. They simply breed too quickly and have too enormous a number of babies. So for me it was daily and I do mean daily maintenance, micromanaging my crop leaf by leaf, that allowed the plants a fighting chance. I hope you get luckier than I was. Maybe that peppermint soap will work for you. I'll be interested to hear if it does.

I read an article earlier this year about spraying with milk and how it kills soft bodied insects.  Generally I have had HORRIBLE aphids and also grasshoppers each year but so far this year they have been very, very minimal.  I'll go look for the article and post it here if I find it.

The gist is this.  The milk sugars are indigestible for bugs that do not have a pancreas.  They eat them when they eat a plant and they die.  The milk is also good for powdery mildew and the like.  It also is a very good "fertilizer" that feeds the bacteria in the soil to make the soil more productive.

You use whole milk and dilute it, I think 1 part milk to 2 or 3 parts water (I've used 3 parts successfully).  I've sprayed it as a foliar spray and sprayed the ground around my squash as well to fertilize.  It doesn't harm any bug that doesn't actually eat the plant.

I sprayed with Dr. Bonner's last night. The spider mites have replaced the aphids. The grasshoppers are just starting so I will try milk on the beans.

Thank you for all of the ideas.  I will try them the next time I find an aphid. They seem to have disappeared for now.

I just saw a grouping of these little on my baby milkweed toward the top. Smashed them all on the leaves...?Ivory soap or milk spray?

Or try a test between milk solution, Ivory soap and Dr. Bonner's liquid peppermint soap.

sanderson wrote:Or try a test between milk solution, Ivory soap and Dr. Bonner's liquid peppermint soap.

Sanderson, is the Dr. Bonners a garden thing? Or laundry?

Actually, a beauty / health thing.  Drug store, some grocery stores.  My husband came back with both a liquid (peppermint) and a bar (lavender), just to make sure one of them was correct.  
https://www.drbronner.com/DBMS/category/PEPPERMINT.html

https://www.drbronner.com/DBMS/BARSOAP/OBLA05.html

I had a gallon of milk go sour on me and have been using it on my bean leaves. It makes them less pretty but it seemed to me to cut back quite a bit on the leaf-eating, which was getting way out of control.

I used it last year to control mildew, but needed to reapply every two days minimum, because there were always spores that survived enough to pop up and spread widely almost immediately.

We do have almost no mildew this year on a badly affected tree, but maybe that's just because it's been too hot and dry. I used to give it plenty of milk last year, but it was hopeless ... too many uneven surfaces on too many leaves meant you could never truly hit everywhere you needed to hit.