HELP PLEASE! My pencil cactus has brown spots all over it and it is not doing well, branches shriveling up and dropping. I’ve tried anti fungal spray but it has not helped. Please let me know what’s wrong and let me know if you have any remedies
It's an infestation of scale insect. Physically remove them by hand using isopropyl alcohol then spray the entire plant to kill the juveniles that are invisible to the naked eye. I believe either isopropyl alcohol or insecticidal soap can be used as the spray; I don't know how this particular plant would react to such a spray so do due diligence. The sprays must be repeated a number of times every 7-10 days until there is no sign of the pest. Scale Management Guidelines--UC IPM
Also, be aware that the plant should not be exposed to sunlight while being sprayed or immediately afterward as that would trigger phototoxicity.
Junglekeeper is correct physically remove and use isopropyl alcohol. Don't use insecticidal soap, it will do nothing in the fight against scale. First before anything else, isolate that plant. Get is as far away from your other plants as possible. You do not want to be fighting this pest on all your plants. You can use something like End-All. Or Neem Oil will smother them, but at too high concentration, it will also clog the pores of the plant.
The soap solution does work but only on the juvenile instars. End-All is insecticidal soap with the addition of pyrethrins and neem oil.
I have never used quotes, so I am sorry, if I get it wrong. Either way, you can see the The U.S brand Safer, made by the company, Woodstream also makes Safer's brand in Canada. The Safer brand in the U.S. has Neem in it's formula. Unfortunately, they unable to offer the same formula in Canada. In case, I was mistaken and something had changed, I went to Woodstream's website. The current formula being sold has; Potassium Salts of Fatty Acids (20%) and Pyrethrins (.2%). Yes, you are correct Potassium Salts of Fatty Acids is Insecticidal soap. I am sorry, for writing my words as a definitive. In my 'opinion', insecticidal soap is a punch the gut, but not a knock out on scale, even the juveniles. That is why I would spend my money on End-All. My whole thing was written to piggy back on your advice, not to diminish. When you wrote, I saw it as an uncertainty, so I was trying to clear it up. How about we stick to supporting each other as fellow plant geeks. We can all learn a lot more with open hearts, open minds & open ears.
My intention was to correct misinformation, not to start an argument; I hope I didn't come across that way. By the way, End-All in Canada also contains neem. Links to Safer's soap products in Woodstream Canada's site can be found in this thread: Safer's Insecticidal Soap, Trounce, and End-All. End-All's complete list of ingredients are listed on its Specs tab. I have been using insecticidal soap with success but have been considering switching to Trounce or End-All for something more potent, one requiring fewer applications for eradication. Do you find the latter to be such for houseplant pests (i.e. scale, spider mite, thrip)? Please reply in the other thread so as to keep this thread on topic.
Can't tell from this one pic alone what the plant is, but it isn't a cactus - that may well affect what treatments you can use on it. Can you add some photos of the whole plant to help identify it?
Yes, not a cactus. I assume this is Euphorbia tirucalli. If so, it brings up the issue of the caustic sap. Be very careful while handling the plant, especially if you decide to trim away parts. The sap can burn and cause blindness if you get it in your eyes.
