Old cactus getting yellow

Kato109 · Post by **Kato109** » Mon Jan 14, 2008 1:21 am

Hey Harald,
thanks again for all the good info.
I took the photo to the guy who runs the nursery near us, who is very knowledgeable. He said most of the things you said. The cacti are being overwatered and are therefore weakened and have got some sort of mites and other stuff growing on them. He gave me an organic spray on pesticide to do once a week for three weeks and we will try to cut down on watering. He also said they need fertilizing.
so i will do all that! and cross my fingers.
Thanks so much for all the help.
take care,
Katarina

Post by **daiv** » Mon Jan 14, 2008 9:41 pm

In the second picture, it looks a lot like scale to me. In any case, be careful with the spray-on insecticide. Many of those will burn your cactus's "skin" when the sunlight hits it. The Bayer systemic that Harald mentioned has worked well for me too.

Oh, and take the garden-hose with a squirt nozzle on it and blast them off your plant! This is not only satisfying, but it will slow them down a lot, but not eliminate them copletely -you will need the insecticide to erradicate them.

Daiv

Kato109 · Post by **Kato109** » Tue Jan 15, 2008 11:39 pm

hmmm. the insecticide he gave me is called Spinosad and its ingredients are spynosyn A and D.
its not very hot here right now. do you think its risky to spray it on the cactus?
It doesnt say its for scale - supposedly its organic and its a smothering agent.
But if you think its dangerous I can go look for the bayer systemic one. is that specifically effective for scale? what is scale?

I have already delighted in washing down the cactus and getting rid of as much of the buggers as possible!
Take care,
Katarina

Kato109 · Post by **Kato109** » Wed Jan 16, 2008 12:48 am

Hey Daiv,
I went online and looked up scale and I definitely think thats what it is because the damage when I washed it off looked just like the damage from the cochineal on my other cactus out front. Its not cochineal cause its not red, but apparently they are in the same family.
so am I right in guessing that a smothering insecticide is not going to do the trick and I need to buy a systemic?
or should I try the smothering first?
thanks,
K

Post by **daiv** » Wed Jan 16, 2008 5:04 pm

Well... this is my opinion, but I would go for the systemic and keep blasting away with the hose now and then until the systemic makes its way up and they no longer return.

Spraying right on the plant will take care of the pests, but when the sun shines you risk getting parts of your plant burned.

Kato109 · Post by **Kato109** » Wed Jan 16, 2008 10:16 pm

thanks Daiv,
we bought a systemic insecticide today and will start with it right away and keep washing them off.
take care,
Katarina

Post by **daiv** » Thu Jan 17, 2008 1:11 am

Sure thing. And if we don't have you here as a frequent member, be sure to check back now and then and let us know how it goes!

But better to jump in find yourself full steam in your new cacti-collecting hobby!

Kato109 · Post by **Kato109** » Thu Jan 17, 2008 1:52 am

Hey Daiv,
I will certainly let you guys know how it goes.
thanks so much for all your help!
Take care,
Katarina

MichaelCactus · Post by **MichaelCactus** » Thu Jan 17, 2008 3:10 am

Lol Daiv, your trying to convert people

Seems "Cactofiles" are like a cult/religion, we should have recruiting meetings and doorknocks hehe.