Be careful what you spray

Trouble shoot problems you are having with your cactus.
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Steve Johnson
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Joined: Thu Nov 03, 2011 4:44 am
Location: Los Angeles, CA (Zone 10b)

Re: Be careful what you spray

Post by Steve Johnson »

JeffWhiteDevil wrote:I don't thnk you can go wrong using Imidacloprid. I have heard negative stuff on the use oils on cacti skin or on their roots but I have no experience with the stuff. The alcohol should be fine as long as you don't over-do-it, I use it myself upon occasion.
Perfect. Imidacloprid is great, and if the only pest problem I'll see is mealies, I'd be a happy camper. Too bad there isn't a systemic on spider mites, though. Alcohol does sound like a good solution for spraying on mites. Hope I never see 'em, but nice to be prepared if those tiny little things ever start showing up on my cacti.
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My location: Los Angeles, CA (Zone 10b)
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Peterthecactusguy
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Joined: Fri Feb 19, 2010 7:49 am
Location: Black Canyon City, Arizona

Re: Be careful what you spray

Post by Peterthecactusguy »

Steve Johnson wrote:Everything was fine, then 2 months later I thought I saw a few mealies on my Stenocactus multicostatus. I was using an insecticide-miticide-fungicide spray with Neem oil for my Habanero plants. Been working well for the Habs over 5 years, so I thought "well, that should be safe for the Steno". Wrong. The plant started showing orange spots in a few days, it was completely orange in a week, and after some more time went by the Steno was obviously dead -- phototoxicity. Learned my lesson there, and an Imidacloprid systemic is the only thing I'll use on mealies. As to spider mites, I've never had a problem with them, but if I do, I'll never use anything oil-based on cacti. Speaking of...

Ian has stated elsewhere that alcohol is effective. However, he was referring specifically to false spider mites at the time, although I believe it would apply to red spider mites as well. I also believe alcohol will not produce a phototoxic reaction, which would be a plus in spraying for mites. I'm not completey certain about that, though, so I've asked for confirmation about this several times. No response yet, but I'd sure appreciate getting an answer one way or 'tother. By the way, I'd be spraying cacti with alcohol out of direct sunlight. Since it evaporates quickly, I can see where it would have a definite advantage over oils and soaps given their residual effects.
Learned your lesson about the Neem oil ? From what I have heard that is bad for cacti, although IT DOES work great for veggies...
Here's to you, all you insidious creatures of green..er I mean cacti.
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Peterthecactusguy
Posts: 8862
Joined: Fri Feb 19, 2010 7:49 am
Location: Black Canyon City, Arizona

Re: Be careful what you spray

Post by Peterthecactusguy »

Steve Johnson wrote:Everything was fine, then 2 months later I thought I saw a few mealies on my Stenocactus multicostatus. I was using an insecticide-miticide-fungicide spray with Neem oil for my Habanero plants. Been working well for the Habs over 5 years, so I thought "well, that should be safe for the Steno". Wrong. The plant started showing orange spots in a few days, it was completely orange in a week, and after some more time went by the Steno was obviously dead -- phototoxicity. Learned my lesson there, and an Imidacloprid systemic is the only thing I'll use on mealies. As to spider mites, I've never had a problem with them, but if I do, I'll never use anything oil-based on cacti. Speaking of...

Ian has stated elsewhere that alcohol is effective. However, he was referring specifically to false spider mites at the time, although I believe it would apply to red spider mites as well. I also believe alcohol will not produce a phototoxic reaction, which would be a plus in spraying for mites. I'm not completey certain about that, though, so I've asked for confirmation about this several times. No response yet, but I'd sure appreciate getting an answer one way or 'tother. By the way, I'd be spraying cacti with alcohol out of direct sunlight. Since it evaporates quickly, I can see where it would have a definite advantage over oils and soaps given their residual effects.
Learned your lesson about the Neem oil ? From what I have heard that is bad for cacti, although IT DOES work great for veggies...
Here's to you, all you insidious creatures of green..er I mean cacti.
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