Question
Cactus
Hi, I hope you can help me I have a Cactus in my Loungeroom that is about 6 foot hight from the base of the pot. One of the stems died. It started to turn yellow at the top, then got scaly and had like a white ash appear on it half way up. So I cut it off and am hoping I can save the other stem. It is also but only lightly turning yellow at the top. It has been in this location for 5 years and gets watered about 4-5 times a year.
Answer Good for you for cutting off that diseased part. I'd separate the the plants into two pots. make sure the roots look healthy and gently get rid of the old soil. With tall plants rule of thumb is that the pot is one third the size of the plant. Put in new , well draining potting mix in clean pots with good drainage. The also should be repotted every two to 3 years. If there is a botanical garden that you can call they can tell you the best mix for your climate. I would put some fungicide in the soil.
The two shoots on your tall plant don't look sick to me tho I'd have to look close up. They look like new growth which is lighter. This is your summer, no? So your plant is in active growth. You can pot them separately as well as they look like they will make the plant top heavy as they grow. If you choose to do that now with one or both let them callous over first after cutting them off with a sterilized knife. On the other hand you can just see what happens. If they present that problem you can repot then then. Next summer when they're all happy and have good roots you can but them in one pot and have a nice variety of sizes in it.
If you have the room I'd put the plants outside for he summer slowly as to prevent sunburn - shade first then gradually put in more sun. I start out by throwing a sheer curtain over the plant and gradually uncover it. Sunshine just makes them so happy. Be especially careful with the new, tender shoots. When winter comes really restrict water and put in a cool place as the plant will go into a dormant phase.
Sorry I've been so tardy by the way. I know that's annoying.
And finally, I'm not sure that it is a cactus. It looks like a succulent, perhaps Euphorbia. I can't see the spines. Cactus have carateristic spines. While some succulents have spines, the formation is different and the care is slightly different. Get a good cactus book or Google 'cactus spine formations' and maybe you'll be able to tell.
You'll definetly need help repotting with that impressive monster!
If you have anymore questions or close up pictures don't hesitate to contact me again
Good luck and good day! Where do you live? I've always wanted to see Australia (perhaps you need some help with the repotting?)
Maureen
