dying leaves on brocc/cauliflower

[emmettdigger]

I had a bit of an aphid problem and found a recipe online that suggested oil + soap + water to spray on the aphids. I did this but the next day, while the aphids were gone, the outer leaves on the plants started to bake. The inner part of the plants are ok but it looks like the outside leaves have been damaged - they're sort of crispy around the edges. Do you think I've ruined my plants or they'll be ok?

[cynthia_h]

It can be frustrating when plants do worse despite our attempts to help them, but their condition today may depend on whether you used SOAP or DETERGENT in your spray. Detergent, which is what many dishwashing liquids are, will burn the leaves of plants. I personally recommend using 1 tsp of liquid soap in 1 quart of water as an initial strength, plus a few drops of oil if you feel it necessary. The most soap I've ever used in 1 quart of water (proportionately speaking; I have a 16-oz. spray bottle) is 1 tablespoon.

What sort of proportions did you use, and are you certain that you used liquid soap vs. detergent?

Cynthia H.
Sunset Zone 17, USDA Zone 9

[jal_ut]

A little Dawn dishwashing detergent with water in a kitchen spray bottle will kill aphids almost immediately. Spray the aphids and wait 5 minutes then rinse the plants with clear water. Then the soap won't hurt the plants. I have never used oil with the soap. This same mix of detergent and water will also kill many other kinds of insects and spiders.

[emmettdigger]

I used Dawn and the proportions that were on the "recipe."

My biggest question, though, isn't about killing the aphids it's about whether the plants are ok or if I should pull them out and start over. The leaves are crispy and look like they're dying. The inner leaves are ok but the outer leaves are not.

[cynthia_h]

Cut the outer leaves off if they're that bad; otherwise, they'll attract pests that eat dead plant matter. Throw the leaves into your compost; they're not diseased, just "past their prime."

The smaller inside leaves will grow, and new leaves will emerge from the center.

Don't pull up the plants unless they start to go to seed ("bolt"). Even then, if you plan to save the seeds, let them flower and produce seed pods; you'll be pleased (probably ) at the number of bees, dragon flies, and other pollinators who visit flowering veggie plants.

Cynthia

[rainbowgardener]

Dawn makes a lot of different products ... some are called dish soap and some are just called dishwashing liquid. The ones called dish soap are soap. The ones called dishwashing liquid are DETERGENT. The detergent does burn plants and can cause exactly the symptoms the emmet described.

If it was detergent used on the plants, I'd rinse them well, take off the burned leaves. Plant should recover.


"This same mix of detergent and water will also kill many other kinds of insects and spiders." Really Jal you should be saying SOAP. Detergent will certainly kill the insects, but so will the soap. Maybe you in your conditions and super large healthy plants can get away with spraying them with detergent, but most people will have the same problem emmet did if they try it. And maybe you are actually using Dawn dish soap?

[garden5]

I wish that these folks who put out these home remedies would elaborate more on the crucial/commonly mistaken parts. It would save others a lot of time and trouble.

[rainbowgardener]

Sorry, if you had trouble, but every single one of the dozens of times I have mentioned the soapy water spray remedy, I have made sure to say SOAP not detergent, dishwashing liquid is detergent which is harmful to plants. You can use the Search the Forum feature to find how many times I have written that all out!

[DoubleDogFarm]

Don't pull up the plants unless they start to go to seed ("bolt"). Even then, if you plan to save the seeds, let them flower and produce seed pods; you'll be pleased (probably ) at the number of bees, dragon flies, and other pollinators who visit flowering veggie plants

cynthia_h,

This can be a as big a problem as home remidies if not told proper procedures. Open Pollinated, No F1, no cross pollination. Its a lot of work. I personal would just eat the flower heads. They are delicous in salads and stir fries.

[cynthia_h]

Truedat w/regard to the F1 hybrid, etc. Mine are all OP and fine for seed saving.

But in any case, the pollinators coming for visits are a wonderful plus! When a veggie plant "gets away" from me, I just go, Oh well, more seeds *and* more bees.

Cynthia

[DoubleDogFarm]

yes, only if you take precaution from cross pollinating contamination.

[jal_ut]

"This same mix of detergent and water will also kill many other kinds of insects and spiders." Really Jal you should be saying SOAP.

If it were soap, I would say soap. Here is the MSDS for the product I use. It is definitely labeled a detergent.

[url=https://www.head-start.lane.or.us/administration/documents/MSDS/Dawn%20Liquid%20Hand%20Dishwashing%20Detergent.pdf]Click Me![/url]

[jal_ut]

Have you ever used insecticidal soap? Check this MSDS out too.
[url=https://titanarum.uconn.edu/msds/insecticidal_soap_msds.pdf]Click Here![/url]

I will stick with my Dawn.

[jal_ut]

This is also a worthwhile read on detergent. [url=https://en.wikipedia.org/wiki/Detergent]Click Here![/url]