The Incredible Shrinking Cactus!

My peanut cactus (chamaecereus silvestrii) is smaller than it used to be. Not a little bit smaller -- more like half the size! There doesn't seem to be anything wrong with it. It's entirely healthy so far as I can tell, with no alarming signs. It's just shrunk! It's just the main branch measured probably 10 cm a few months ago, and now it's more like 7. It also seems slimmer.

There's two things that I should mention. One is that it now has ten branches, whereas last year it only had two. The other is that I watered it quite heavily last year, but I've watered it much less during the last few months.

Do cacti get smaller if they use up their stored water? Or can growing extra branches draw nutrients from the flesh of larger branches?

 

Yes.

Don't know, my cacti do not grow when I don't water them. I think it's possible, I once had a peanut cactus cutting in my fridge that started to grow, and of course the stem shrunk when the tip grew, as it did not have any roots.

Have you checked for root mealies or root loss? Especially the former can make plants shrink quickly if it is a heavy infestation.

 

My guess is, it either needs water or, has been been over-watered and is rotting.

 

My chamaecereus has done the exact same thing. It was a lot bigger when it had fewer arms, but as it puts on more branches, it seems to have gotten progressively smaller year after year. Certainly the arms are shorter and less robust than in the beginning. Otherrwise it seems healthy and always puts out loads of flowers.

 

The correct name of former Chamaecereus silvestrii is now Echinopsis chamaecereus.

Your plants were probably "pumped up" by some wholesale nursery when you bought them and they have shrunked down to their normal size under nomal care.

 

I have had 2 different plants of E chamaecereus die very similarly which is due to fungus within the plant. It appears to be very susceptible to this problem. Both were big box store buys, and if I try again with this plant, I think I will stick to nursery stock and sales.

 

Did your plants look sickly when it happened? The point I and Tumamoc have noticed is that our plants seem entirely healthy. Just smaller.

 

you know mine was like that until we got a nice pour down of rain. now its twice as big