HELP SPOTS

[scousetigger]

HELP. I have just been to look at my cacti after their winter break and have found that 2 of them have orangy large spots. Some appear raised as well. What is wrong and is it catching?:S

[scousetigger]

[attachment 2542 spots.jpg]

[scousetigger]

[attachment 2543 DSCF0023.jpg]

[Roy]

I think you have let them get too cold.

[Mal]

Yes, thats the answer toooo cold!!!!!! regards mal..

[Vic]

Yes definitely a spot of frost bite - blue cereus type cacti usually prefer warmer temps - 10C plus I'd presume.

[David Neville]

Hi Scousetigger,

Don't despair too much about the orange spots on the two plants you supplied pix of. In fact Myrtillocactus geometrizans and Echinocactus grusonii are two of the best known culprits for developing these orange marks if they suffer too much cold. Unless the temperature dropped below freezing I doubt that either of the plants will die, but the marks themselves will never disappear completely.

This Myrtillocactus is widely used as a grafting stock on the continent and elsewhere, but it has never been too popular in the UK because of its dislike of cold temperatures -- this is partly because us UK growers tend to be more stingey regarding winter heat, whereas overseas growers seem more willing to provide a higher minimum winter temperature for their plants.
When I was in central Mexico (in the state of San Luis Potosi) I saw many 1000s of large, mature, multi-branched specimens of M. geometrizans that were completely dead -- there had been some colder than usual weather the previous year, with sub-zero temperatures, and these plants in some areas were almost totally wiped out!

Echinocactus grusonii seems to be particularly sensitive to the cold as a young plant, and develops these orange marks very easily. It seems to me that they are slightly less sensitive as they get older.

David Neville
Southampton & District BCSS

[Guest]

I have a 6'branched geometrizans v grandiareolatus free to a good home.

S Herts. and will need collecting.

Any tAkers?

Mike.