Gymno lost its colour

[gillinger]

I've seen coloured Gymnocalycium varieties grafted onto columnars but is it normal for one to turn this weird orange colour? It was green about a month or so ago. It seems to have happened since I started watering. The plant is still firm, no mushy bits. All my other cacti are fine. Should I be worried?

[anttisepp]

These guys usually grow in grass and under tree canopy so it's not unusual colour changing in direct sun. Move it in a bit shaded not very hot place and give it whole summer enough water because anisitsii/damsii as mihanovichii &co like it very much.

[gillinger]

Thanks. I'll give that a try. No sun forecast here for the next week so that should help!

[zpeckler]

These guys usually grow in grass and under tree canopy so it's not unusual colour changing in direct sun. Move it in a bit shaded not very hot place and give it whole summer enough water because anisitsii/damsii as mihanovichii &co like it very much.

This is the advice I didn't know I was looking for!

I have a horstii and an anisitsii but don't know a lot about S. American cacti habitat. The anisitsii is pretty young and shortly after I got it two years ago it turned from green to purple and has been really slow growing. From what you're saying I think it might be sun and heat stress because during the growing season it's been getting hours of California sun (through a 30% shade cloth) and 90-100F heat.

I don't know if G. horstii likes the same conditions in its native habitat, but mine is a champ. It's one of the oldest cacti I have and in the beginning survived many, many newbie cactus grower mistakes that killed a lot of its contemporaries. It takes full sun and the heat better then some of my Ferocactus do!

[Steve Johnson]

I've seen coloured Gymnocalycium varieties grafted onto columnars but is it normal for one to turn this weird orange colour? It was green about a month or so ago. It seems to have happened since I started watering. The plant is still firm, no mushy bits. All my other cacti are fine. Should I be worried?

A few questions for you:

The Gymno didn't suddenly change from green to orange overnight -- when did you start noticing the color change?
When did you start watering?
How long have you had the plant?
Is it getting direct sunlight or filtered light?

The reason I ask the 4th question -- clear glass in a window or greenhouse isn't good for scorch-prone cacti, and I believe the species of your Gymno qualifies. However, filtered sunlight through polycarbonate material shouldn't be a problem, so if that's what you're using, I'd be looking at a problem not related to light levels.

[gillinger]

I've seen coloured Gymnocalycium varieties grafted onto columnars but is it normal for one to turn this weird orange colour? It was green about a month or so ago. It seems to have happened since I started watering. The plant is still firm, no mushy bits. All my other cacti are fine. Should I be worried?

A few questions for you:

The Gymno didn't suddenly change from green to orange overnight -- when did you start noticing the color change?
When did you start watering?
How long have you had the plant?
Is it getting direct sunlight or filtered light?

I've had the plant about four years or so. It was a kind of greeny-red last year but greened up over the winter. I started watering beginning April. My greenhouse has ridged polycarbonate sheeting on the sun side and all my plants were in there last year.
I've now put it into shade, somewhere a little cooler and I'll keep an eye on it.

[Steve Johnson]

I've seen coloured Gymnocalycium varieties grafted onto columnars but is it normal for one to turn this weird orange colour? It was green about a month or so ago. It seems to have happened since I started watering. The plant is still firm, no mushy bits. All my other cacti are fine. Should I be worried?

A few questions for you:

The Gymno didn't suddenly change from green to orange overnight -- when did you start noticing the color change?
When did you start watering?
How long have you had the plant?
Is it getting direct sunlight or filtered light?

I've had the plant about four years or so. It was a kind of greeny-red last year but greened up over the winter. I started watering beginning April. My greenhouse has ridged polycarbonate sheeting on the sun side and all my plants were in there last year.
I've now put it into shade, somewhere a little cooler and I'll keep an eye on it.

I should've been more specific with my first question -- when did yo first notice the skin color starting to change from green to orange? Since you've had the Gymno for about four years, I'm assuming that this is the first time you've seen orange showing up on the skin. If so, it's an abnormal change which needs to be investigated. Under the "better safe than sorry" rule, IMO you should investigate this -- from Cactus Nursery in the UK:

• "Root mealybugs (Rhizoecus falcifer) are among the worst pests of cacti and other succulents. They live almost exclusively on roots and the parts of the stem that are below the surface. They are similar to stem and spine mealybugs in that they also secrete whitish, woolly, or powdery wax. Root mealybugs prefer dry substrates. They multiply particularly rapidly during the dry winter dormancy period. Affected plants look pale, become sickly, and gradually die. Plants damaged and weakened by root mealybugs are especially susceptible to fungal diseases."

Your Gymno obviously doesn't look pale, but a root mealy infestation could be the cause of the abnormally orange skin. There's only way to find out -- unpot the plant, and take a good look at the roots. If you do have root mealies, give the roots a good soak with 2% insecticidal soap solution. When the roots are dry after the soak, repot the plant in fresh potting medium.

If your Gymno doesn't have root mealies, take a look at the possibility of root rot -- unless you're heating your greenhouse at night, I'm not sure if you should've been watering anything in early April. I personally don't give my cacti their first deep drink of the growing season until the overnight lows are consistently above 10C. SoCal just went through an unusually cold and persistent winter, and the first time conditions were favorable enough for it was -- two days ago.

[keithp2012]

It needs more water