Voting Booth: Which of these causes leaves to turn purple or red? , 1 by Agavegirl1

Agavegirl1 wrote:
Hi,
This may be a good article! Why don't cacti change colors in the Fall?

Here's the best info I found...PLEASE CORRECT ME if I'm inaccurate. I'm no expert and still learning. I hate to misspeak or sound like I know more than others, especially if my info isn't right.

Best I can gain is that cacti, Agaves and Aloes, Barrels, etc. are evergreen plants who use their body to store water and has a system internally that feeds them and helps with photosynthesis (CMS..or is it CSM) that is different than plants with "leaves" . Since they are evergreens they don't turn colors.

The colors that they do have, like the Santa Rita Opuntia, (link above) which shows purple are natural variations from the breeding of species and hybrid varieties. Usually this color pales or deepens depending on how much water and sunlight they get rather than cold and the seasons. Could also depend on age/maturity of plant.

You can deliberately 'stress' some Aloes and Agaves and prickly pear into changing color by limiting their water or increasing their sun exposure but changing color it isn't something they would do naturally every season like leaves.

All cacti are succulents BUT not all succulents are cacti. Has to do with the way the spines grow out of the areoles. This is why Sedums, Sepervium, etc. are succulents but not cacti. It may be also why they change colors more readily. Their photosynthesis is different somehow. Sauguaro and Prickly pear with areoles really don't change colors.

Best I can come up with.
If anyone has more concise info...PLEASE share.

My Santa Rita p.pear. Gets partial shade all year long and is tended to by me so it also gets regular water.

My Beaver tail p.pear. It never changes color all year long regardless of 110 degree heat and full sun.

An A. ferox. Normally the leaves are green. This was taken in the Summer when it was very hot. This plant was in public landscaping and in full sun so it probably wasn't getting watered regularly. Wish it was mine! Pretty when 'stressed' isn't it!

This message was edited Nov 6, 2015 7:33 AM