isopropyl alcohol

pinakbet · February 16, 2011

is this harmful to plants if I spray it as a control for aphids?

I'm planning to use the 40% concentration.

Stepheninky · February 16, 2011

Quote:

Originally Posted by pinakbet

is this harmful to plants if I spray it as a control for aphids?

I'm planning to use the 40% concentration.

It can cause damage to plants, some plants with waxy leaves might could tolerate it better.

Garlic Oil spray works too
To make garlic oil spray, mince or finely chop three to four cloves of garlic, and add them to two teaspoons of mineral oil. Let this mixture sit for 24 hours. Strain out the garlic pieces, and add the remaining liquid to one pint of water. Add one teaspoon of liquid dish soap. This mixture can be stored and diluted as needed. When you need to spray, use two tablespoons of the mixture added to one pint of water in a spray bottle.

What ever you end up using I would start by spraying one leaf and waiting a couple of days to see how it effects the plants. If you see yellowing of the leaf do not use it.

pinakbet · February 16, 2011

a friend reccomended me to use alchohol on aphids. that how he control aphids on his plants.

thanks for the recipe of the garlic spray.Can I substitute mineral oil with any cooking oil?

BlackestKrim · February 16, 2011

I have found soapy water helps with aphids, and doesn't hurt the plants.

RinTinTin · February 17, 2011

If you have access to wood ash (yeah, I know you don't have a lot of fireplaces in the Filipines), or BBQ ash, sprinkle them on the aphids. The next rain will wash their dead bodies onto the soil. Clean, simple, organic, and CHEAP, plus you don't have oily/sudsy residue on the plants.

pinakbet · February 17, 2011

Quote:

Originally Posted by BlackestKrim

I have found soapy water helps with aphids, and doesn't hurt the plants.

I tried that already (with various soap concentration)but they are back just a couple of days later..

Quote:

Originally Posted by RinTinTin

If you have access to wood ash (yeah, I know you don't have a lot of fireplaces in the Filipines), or BBQ ash, sprinkle them on the aphids. The next rain will wash their dead bodies onto the soil. Clean, simple, organic, and CHEAP, plus you don't have oily/sudsy residue on the plants.

This is new to me... Now I need to look for a supply of wood ash. thank Rin.

FilthyRich · February 22, 2011

Pyrethrin spray kills aphids very well. Be aware though it also kills bees so spray late afternoon, after the bees have finished their work for the day.

David Marek · February 24, 2011

40% is quite strong. I use 10% on houseplants, but have never tried it outside. Recently, I have avoided spraying anything with alcohol. First I read ethyl was less damaging to plant tissue than isopropyl, but later read that ethyl is absorbed into the plant tissues and messes up the plants' ability to breathe, so I'll watch this thread for other's experience.

Quote:

Can I substitute mineral oil with any cooking oil?

The more pure the oil, the less chance of plant injury. If you can find it, ultrafine oil is intended to be used on plants, and mixes well with water.

rtvvvv · April 18, 2015

just found aphids all over some basil from home depot..i had repotted them and a week passed before i noticed the leaves looking wilted. just hit them with
91% isopropyl I can report the aphids are seriously dead. Will report back on the basil ..no big deal if it dies, it was mostly for an experiment with the iso. might give it a try on some tomato leaves if i see any white flies.

RayR · April 18, 2015

2 Parts 70% Isopropyl Rubbing Alcohol/1 Part Water will kill aphids and spider mites well enough. No toxicity on Tomato, Pepper or Strawberry leaves that I've used it on. Probably no issue with basil either. The alcohol evaporates very quickly.

Blueaussi · April 21, 2015

Aphids have a very short life cycle, and will keep repopulating a plant unless every single egg and aphid are removed. And even if you do that, they may repopulate from the plant next door. I prefer controlling them with beneficial insects. What native insects eat aphids where you live?

You can also control, but not eradicate aphids with a blast of cold water from a hose. Or just by squishing them with your fingers.

rtvvvv · April 21, 2015

I dont know!...never had aphids till i picked up that basil plant from HD..I moved them from the GH straight away..I don't think they could have spread in that time.

Blueaussi · April 22, 2015

I was kinda thinking about the original poster, pinakbet, who appears to be outside the US. Sorry if that was confusing! If you're in Michigan, the ladybugs will probably show up if you didn't get all the aphids killed!

February 16, 2011	#1
pinakbet Tomatovillian™ Join Date: Jul 2010 Location: Pearl of the Orient Posts: 333	isopropyl alcohol is this harmful to plants if I spray it as a control for aphids? I'm planning to use the 40% concentration.

February 16, 2011	#4
BlackestKrim Tomatovillian™ Join Date: May 2009 Location: Austin, Texas Posts: 147	I have found soapy water helps with aphids, and doesn't hurt the plants.

February 17, 2011	#5
RinTinTin Tomatovillian™ Join Date: Aug 2010 Location: Seattle Posts: 581	If you have access to wood ash (yeah, I know you don't have a lot of fireplaces in the Filipines), or BBQ ash, sprinkle them on the aphids. The next rain will wash their dead bodies onto the soil. Clean, simple, organic, and CHEAP, plus you don't have oily/sudsy residue on the plants.

February 22, 2011	#7
FilthyRich Tomatovillian™ Join Date: Sep 2010 Location: Sydney, Australia Posts: 26	Pyrethrin spray kills aphids very well. Be aware though it also kills bees so spray late afternoon, after the bees have finished their work for the day.

April 18, 2015	#9
rtvvvv Tomatovillian™ Join Date: Feb 2015 Location: mi Posts: 80	just found aphids all over some basil from home depot..i had repotted them and a week passed before i noticed the leaves looking wilted. just hit them with 91% isopropyl I can report the aphids are seriously dead. Will report back on the basil ..no big deal if it dies, it was mostly for an experiment with the iso. might give it a try on some tomato leaves if i see any white flies.

April 18, 2015	#10
RayR Tomatovillian™ Join Date: Jun 2010 Location: Cheektowaga, NY Posts: 2,466	2 Parts 70% Isopropyl Rubbing Alcohol/1 Part Water will kill aphids and spider mites well enough. No toxicity on Tomato, Pepper or Strawberry leaves that I've used it on. Probably no issue with basil either. The alcohol evaporates very quickly.

April 21, 2015	#11
Blueaussi Tomatovillian™ Join Date: Apr 2009 Location: South Carolina Zone 8a Posts: 1,205	Aphids have a very short life cycle, and will keep repopulating a plant unless every single egg and aphid are removed. And even if you do that, they may repopulate from the plant next door. I prefer controlling them with beneficial insects. What native insects eat aphids where you live? You can also control, but not eradicate aphids with a blast of cold water from a hose. Or just by squishing them with your fingers.

April 22, 2015	#13
Blueaussi Tomatovillian™ Join Date: Apr 2009 Location: South Carolina Zone 8a Posts: 1,205	I was kinda thinking about the original poster, pinakbet, who appears to be outside the US. Sorry if that was confusing! If you're in Michigan, the ladybugs will probably show up if you didn't get all the aphids killed!