This might make you very uncomfortable

[fanaticactus]

Now that we're in Daylight Savings Time and I'm ready to assess the damage done by this severe winter, I've been venturing into the GH to rescue what I can bit by bit. Because of the extreme cold all winter, the (what I calculated would be a slightly more than adequate) heater was unable to maintain temperatures at 38-40F most nights. I took the advice several of you offered and covered the cacti with layers of newspaper and draped old cotton mattress pads over the ones on stands. I knew my mealybug epidemic would spread like wildfire and was prepared for almost every cactus to be dead from the cold. Recently, I've been peeking under those protective layers to see which cacti could be rescued and prepped for Spring. Several with only minor bits of mealies I've been treating with toothpicks & swabs dipped in isopropyl alcohol then spraying with Safer's insecticidal soap. That process seems to have pretty much kept the infestations somewhat manageable. Some of the more widespread cases I've been treating with a soap soaking bath (about an hour), using Fels Naptha (grated & dissolved in water). Just this past week I began to use a tiny bit of a Bayer imidacloprid systemic on the ones that I've been watering very lightly once a month during the Winter, as I know systemics don't work unless the roots are functioning. I'll wait to use the Bayer on others until they've had a couple of light waterings to waken the roots. Some heavily infested cacti with dense & dangerous spines I simply threw out without a second thought; a M. senilis especially comes to mind! Unless you think differently, I guess these two (T. setispinus & G. baldianum) will also hit the trash.

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I was very surprised (relieved and happy) to note that several cacti in the midst of others covered with mealies got away unscathed, namely many Echinocereus, Mamms, Gymnos and--to my great surprise--almost all the Echinopsis/Lobivia/Chamaecereus hybrids. These latter ones I always thought were extremely sensitive to pests because of their thin epidermis. Are there some genera of cacti that are to a high degree resistant to mealies and other bugs? It just seems so counter-intuitive to me. One of the Echinopsis hybrids actually has a small bud beginning!

[oldcat61]

Why don't you just spray them with the Bayer 3-in-1 from the box stores? I wouldn't waste time picking them off or dabbing with IPA. I've seen worse recover after spraying. Some of my " rescues" were at least that bad & are thriving now. You might have a scar or two but they'll grow out of it. Sue

[fanaticactus]

Why don't you just spray them with the Bayer 3-in-1 from the box stores? I wouldn't waste time picking them off or dabbing with IPA. I've seen worse recover after spraying. Some of my " rescues" were at least that bad & are thriving now. You might have a scar or two but they'll grow out of it. Sue

It just didn't seem possible that infestations like those could possibly recover, Sue. Besides, I can't find any store up here that has the handy sized Bayer 3-in-1, except in a gigantic bottle that's supposed to be attached to a garden hose for wide area application. It's not the "pest" season, so most plant sprays are rare. I have a smaller container of Bayer Advanced Complete Insect Killer (with 0.72% imidacloprid), which I'm mixing with a gallon of water at a time for watering the pots.

[BarryRice]

Aw. Tough times, man.

[AgavaSK]

Ou my.... you have "snow" on your cacti
I think you won`t be able to get rid of them only by manually removing. You will need some chemistry for sure. Becouse even if you don`t see them on the other cacti is almost inevitably that they stay ok, becouse this scum can be hidden very well. Maybe at this point look like that your cacti are not harmed but they can`t stay ok after this invasion.

I wish you to solve this problem very quickly so that your cacti will be able to start growing season very well.

[oldcat61]

There's always a solution. Get anything from Home Depot at this point. I've used the big spray on the garden hose stuff - just adjust your spray pattern. If you want to be precise, you could spray that into a bucket & then pour into a spray bottle. I'd just get the big sprayer thing & do the whole greenhouse from roof to floor - get all the nasties hiding in the corners. Don't give up! Cactus are not disposable toys. Sue

[fanaticactus]

There's always a solution. Get anything from Home Depot at this point. I've used the big spray on the garden hose stuff - just adjust your spray pattern. If you want to be precise, you could spray that into a bucket & then pour into a spray bottle. I'd just get the big sprayer thing & do the whole greenhouse from roof to floor - get all the nasties hiding in the corners. Don't give up! Cactus are not disposable toys. Sue

We'll see, Sue. Right now it's still too cold to even think about getting the GH ready for Spring--especially not with another major storm coming on Wednesday night into Thursday. As for snow, we've been lucky (but not if you ask ski enthusiasts and resort owners!). In our little corner we've had only two plowable storms of about 7" each. Anything else has been flurries with maybe only a couple of inches every once in a while. As you're aware, the NE coast has been slammed a lot. Looks like I'll have yet a couple of months to consider what to do for growing season.

[fanaticactus]

Ou my.... you have "snow" on your cacti
I think you won`t be able to get rid of them only by manually removing. You will need some chemistry for sure. Becouse even if you don`t see them on the other cacti is almost inevitably that they stay ok, becouse this scum can be hidden very well. Maybe at this point look like that your cacti are not harmed but they can`t stay ok after this invasion.

I wish you to solve this problem very quickly so that your cacti will be able to start growing season very well.

Thanks for your positive thoughts, Agava. I am always vigilant about those pests and am standing by with soap sprays and systemic insecticides. But it's a challenge!

[Steve Johnson]

I have a smaller container of Bayer Advanced Complete Insect Killer (with 0.72% imidacloprid), which I'm mixing with a gallon of water at a time for watering the pots.

Have you given your affected cacti the soil soak yet? The reason I ask is that they need to be in growth before the Imidacloprid works its magic as a systemic. From the photos you showed us, it looks like your mealy-infested cacti are still shriveled from their winter dormancy. Before you reach for the Bayer Advanced, water them first and see what they're doing. Signs of new apical growth would be excellent, although if they plump up in response to water, you'll know the roots are working. Then do the soil soak when the mix has dried out. Given the severity of these infestations, figure on about a month before you see a whole bunch of dead mealies falling off when you clean up the plants. I've had to do soil soaks only a couple of times, and I was diluting my Bayer Advanced at 1 tbsp. per quart of water. It's really hard to overdose cacti with Imidacloprid, so don't be shy about diluting to that strength.

I totally agree with Sue -- don't give up!

[oldcat61]

Still don't understand why you just don't spray with any kind of insect contact killer right NOW. The systemic can wait but kill the adults ASAP with anything from the big box stores that is labeled for houseplants. Spectracide makes a good product & the Bayer rose spray will kill the mealies while you wait for spring. Sue

[fanaticactus]

Still don't understand why you just don't spray with any kind of insect contact killer right NOW. The systemic can wait but kill the adults ASAP with anything from the big box stores that is labeled for houseplants. Spectracide makes a good product & the Bayer rose spray will kill the mealies while you wait for spring. Sue

I've only been using insecticidal soap, Sue, and have been a bit reluctant to use anything stronger because of our two cats. Granted, they don't venture too close to the spiny ones, but I have no "safe" area to give the cacti a thorough spray and let them dry. Most of the killer sprays I know have warnings about pets and environmental areas.

[fanaticactus]

I have a smaller container of Bayer Advanced Complete Insect Killer (with 0.72% imidacloprid), which I'm mixing with a gallon of water at a time for watering the pots.

Have you given your affected cacti the soil soak yet? The reason I ask is that they need to be in growth before the Imidacloprid works its magic as a systemic. From the photos you showed us, it looks like your mealy-infested cacti are still shriveled from their winter dormancy.

Only the ones I've kept indoors for the Winter and gave sips of water to. I can even see some lighter green on a few of them now. Those are the ones already dosed with the systemic. I'm aware I'll have to wait for a while and a couple of light waterings before the roots on the dormant ones are ready to draw up any of the Bayer. I didn't know the dilution could be so heavy as a Tbsp. per quart. Perhaps I'll try that. What do you do with the runoff? They strongly caution against just pouring it into the ground (and most likely down the drain), as both would get it into the ground and be harmful to good bugs, like bees. Also, is it dangerous to get on your skin?

[Steve Johnson]

Have you given your affected cacti the soil soak yet? The reason I ask is that they need to be in growth before the Imidacloprid works its magic as a systemic. From the photos you showed us, it looks like your mealy-infested cacti are still shriveled from their winter dormancy.

Only the ones I've kept indoors for the Winter and gave sips of water to.

Sorry, but if those winter sips included Imidacloprid, it wasn't doing anything systemically yet.

What do you do with the runoff? They strongly caution against just pouring it into the ground (and most likely down the drain), as both would get it into the ground and be harmful to good bugs, like bees.

Catch the Imidacloprid-laced runoff in a disposable aluminum pan, then pour it into an empty plastic jug for storage before you can get to a home hazardous waste drop-off point.

Also, is it dangerous to get on your skin?

Not a problem, although if you're still worried about it, latex kitchen gloves you can find at your local store are perfect.

[fanaticactus]

Have you given your affected cacti the soil soak yet? The reason I ask is that they need to be in growth before the Imidacloprid works its magic as a systemic. From the photos you showed us, it looks like your mealy-infested cacti are still shriveled from their winter dormancy.

Only the ones I've kept indoors for the Winter and gave sips of water to.

Sorry, but if those winter sips included Imidacloprid, it wasn't doing anything systemically yet.

Don't worry, Steve...the winter water was just pure ol' Vermont water. I just started with the systemic this past week. And thanks for the tips on disposal and skin contact.

[hoteidoc]

Dave - If you haven't tossed it yet, I'd be inclined to try to rescue the baldianum, just because it's "relatively" CH, at least in your GH. Infestation moderate @ worst. I'd be spraying it with 70% IPA q 10 days for @ 3X. Enjoy today, tomorrow's supposed to be a "dooser"!