soap burn?

I had a small infestation of spider mites, so i read to use a soap spray on the leaves to eradicate them. worked well, but within 24hrs all the leaves i sprayed were brown and crispy. By now they have probably all died, but I think the bines are ok.

Too high concentration of soap?

Will the plant still flourish?

Did you do it when the sun was shining? The water droplets will act like a magnifying glass and the sun will burn the leaves.

Or you could have mixed it too strong, but my guess would be the former.

Wow, what a concept! Is that a common reason for hop leaves to be spotty?



This is a close up of the base of my new Cascades. You can see the smaller spots. Do you think that is from the water droplets? The sun has been pretty strong here in Charlotte NC the past few weeks.

Thanks!

-John

If you used heavy duty dish soap with super duper grease breakers and so forth and such as, the compounds can hurt plants.

damdaman is right about spraying while the sun is shining, but I don't think it would have that dramatic effect so quickly, but I could be wrong!


When using soap solution to kill aphids and mites and such, the only thing the soap does is reduce the surface tension of the water so the insects that drink through their exoskeleton basically drown; they can't regulate how much water they absorb.

The same goes for the plant itself. When the water is soaped like that, the plant can't not take in whatever is in the solution. If other weird compounds are in the soap, it's going straight into the plant.

It's all fine and dandy to do the organic gardening thing in this scenario, as long as the soap you are using is organic. Otherwise, just use regular pesticides and be done with it. Be sure your pesticide of choice breaks down quickly so you don't end up drinking it in your brew. One of the bad things about the internet is that there are 50 million airhead hippies with organic gardening and food blogs, but they have no idea what they are talking about and they all repeat each others' horse **** information until it becomes truthy. Don't read any more organic gardening blogs, and don't spray any more soap on your plants.

Sevin Dust isn't just a ********* rape-rock band, it's a great pesticide.

Spider mites love heat and dry and dust. so lots of water and keep the dust down. Also the hops will send out new leaves and sidearms if the bine is not fried. Lots of water and throw at little food in there-- something like 2-4-6 for bringing the plant back.

Good Luck
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Fletch78 said:

...damdaman is right about spraying while the sun is shining, but I don't think it would have that dramatic effect so quickly, but I could be wrong!

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My wife watered our lemon tree in the middle of the day (had planted it the week before) and sprayed all the leaves aswell, by the afternoon all the leaves were wilting and within the next few days they had gone brown and started dropping. I was amazed at how quick it happened!

Fletch78 said:

...but they have no idea what they are talking about and they all repeat each others' horse **** information until it becomes truthy...

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Can't think of anywhere else on the internet that happens

This is a close up of the base of my new Cascades. You can see the smaller spots. Do you think that is from the water droplets? The sun has been pretty strong here in Charlotte NC the past few weeks.

Click to expand...

It certainly could be, hard to say...

Some leaves are more susceptible to sunburn from water than others. Big, waxy broccoli leaves in my garden are never affected. But sensitive, succulent chard and spinach are very susceptible, for example. Here's some pictures of sunburn on my chard and spinach plants. This was caused by a heavy shower that passed quickly and then the sun coming out. The plants will be fine, but the individual leaves that are burned are probably no longer good eating.

My experience with hops so far has been that they do not burn as easily as chard and spinach for example, but they can burn, especially if you coat the whole plant in soapy water in the middle of the afternoon. That being said, I think insecticidal soap is a great, simple, non-toxic solution for certain pests, just use it at night, and don't mix it too strong.

Wow, lots of mis-information about soap sprays.

First of all, soap does not "drown" the insects, actually it dries them out. The soap breaks down the ways coating of the insects and they dry out over the next few hours.

NuclearRich - Yes, the soap spray could have burned your leaves, especially if you sprayed on a sunny afternoon or used too high of a concentration. The plants will recover, but next time just spray in the evening or on a cloudy day. If you have to spray soap in the sun, you can wash it off with a rinse from the hose after 30 minutes or so with little loss of effectiveness.

ForeRunnerBrewer - that does not look like sunburn, it looks like either nutrient deficiency or nutrient excess. If you start a new thread with some close-up photos some of us will be able help diagnose the problem.

MattD2 - it sounds more like your lemon tree just wilted, proper watering of newly planted trees can be much, much harder than it sounds. Sun scald from water droplets would not cause total defoliation.

theredben said:

Wow, lots of mis-information about soap sprays.

First of all, soap does not "drown" the insects, actually it dries them out. The soap breaks down the ways coating of the insects and they dry out over the next few hours.

.

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According to Colorado State University, we may both be right.

http://www.ext.colostate.edu/pubs/insect/05547.html

How soaps and detergents kill insects is still poorly understood. In most cases, control results from disruption of the cell membranes of the insect. Soaps and detergents may also remove the protective waxes that cover the insect, causing death through excess loss of water.

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Great information, and I think the combonation of both too much soap in my solution along with spraying in the sun was a brutal combo.

Thanks for all the replies, it will help me.

so is it best to remove damaged leaves or let them be? one of my bines has a couple leaves with this type of damage covering about 50% of the leaf.

Just let it be. Unless it becomes shriveled up and dry the leaf is still ok