My Euphorbia lactea is sick

[gatorgirl7563]

Ghost Candelabra Plant, Euphorbia lactea
My cactus is sick. A few weeks ago it was fine and beautiful, maybe a few tiny (pin prick or freckle sized) raspberry red dots on it, then - BAM - I looked at it yesterday and could barely believe it was the same plant. I don't know what to do to treat this plant and protect my other plants.

It has strange rings (brown filled with raspberry/pink edges) and brown spreading patches. I've already looked online a little and couldn't find anything like it.

Is it terminal and I should start chopping off branches to try to grow a new plant before the disease spreads to the entire plant? Do I isolate and treat all the plants in the one pot or is this a Euphorbia-only fungus? (Are my Agave, Aloe, Aeonium, Opuntia, Cereus, Epiphyllum, Rhipsalis, Senecio, Crassula, Kalanchoe, Sedum, Echeveria, Dracaena, Haworthia, Gasteria, Gymnocalycium, Ferocactus, Echinocereus, Bromeliad, Adromischus, etc safe?) Do I isolate all the plants within a ten foot radius?

Due to a malfunctioning sprinkler that drowned my plants and induced root rot: I just lost six out of my eight Aeoniums, twelve Aloes, and my Euphorbia stenoclada. My Ric rac cactus literally fell apart and I have just given up on my Epiphyllum petalum, which is thriving so well (except for flowers) that it is absolutely taking over my garden. Oh, and I haven't been able to replant my torn-down Dragon fruit plant for the eighth day in a row. Also, I just realized that neither of the two Medusa's Head cutting I bought are actually Euphorbia flanaganii.

I'm pissed off, depressed, and desperate. Please, someone, help my save my Ghost Candelabra.
I don't know what to do!

[Aichybatoal]

It definitely looks like a scale insect to me. Scale insects build a flat, circular shield around them to protect themselves from physical and chemical attack. They then puncture the skin and parasitize the poor plant from underneath their bunker. They even reproduce and lay eggs underneath this shield. You see how each of those spots has (from the outside in) a red circle, a pale yellow disc, another red circle, and then an off-white circle at the center? The circle in the center is the scale insect inside its cocoon, and the yellowish area surrounding it is the rot that it has caused over time from sucking the plants juices (the red circles, I think, just kind of mark the boundaries between the two areas). If you decide that this is NOT a scale insect, then I, too, am clueless. If, however, it IS a scale insect, then here is what you can try. Water/soak your cactus with a systemic insecticide, because their waxy fortress is very resistant to contact pesticides. That may kill the insects, but as far as I know, the damage they've already done is permanent ... Sadly, the infestation MAY be too advanced to be broken, but I do wish you the very best of luck, and the same to your Euphorbia!

[Steve Johnson]

It definitely looks like a scale insect to me. Scale insects build a flat, circular shield around them to protect themselves from physical and chemical attack. They then puncture the skin and parasitize the poor plant from underneath their bunker. They even reproduce and lay eggs underneath this shield. You see how each of those spots has (from the outside in) a red circle, a pale yellow disc, another red circle, and then an off-white circle at the center? The circle in the center is the scale insect inside its cocoon, and the yellowish area surrounding it is the rot that it has caused over time from sucking the plants juices (the red circles, I think, just kind of mark the boundaries between the two areas). If you decide that this is NOT a scale insect, then I, too, am clueless. If, however, it IS a scale insect, then here is what you can try. Water/soak your cactus with a systemic insecticide, because their waxy fortress is very resistant to contact pesticides. That may kill the insects, but as far as I know, the damage they've already done is permanent ... Sadly, the infestation MAY be too advanced to be broken, but I do wish you the very best of luck, and the same to your Euphorbia!

Depending on gatorgirl's situation, I wouldn't give up on this plant just yet. A systemic is the only way to effectively put down infestations with any type of scale. So there you go -- an Imidacloprid soil soak. Unfortunately I cultivate only cacti, so I don't know if her Euphorbia is currently growing or dormant. If it is, go for the soil soak immediately in the plant's next watering. If not, a systemic will be useless, and the plant may not survive an infestation that's so far advanced.

By the way, I'm dealing with an armored scale problem on my Coryphantha retusa. I was able to catch it very early on, so I'm getting lucky here under the circumstances -- the roots are actively taking up water, it's still early in my growing season, and the plant wouldn't mind deep watering right about now. Kinda on the cool side today and tomorrow, but I'll give it an Imidacloprid soak tomorrow night as the weather is due to heat up again starting on Monday. Systemics take awhile to kick in before the plant's juices become fully toxic to scale insects. Such being the case, we won't expect miracles overnight. Gatorgirl, if the growing season is right for your Euphorbia, be patient, and I think your scale infestation will start clearing up in about 3-4 weeks after you apply the soil soak.

Hope this works out for you, and let us know how things are going on your end.