Yeah it's called Air Pruning
BUT
I'll side with Phil K on this one shine!
I tried smart pots for a couple of companies.....I gave bad reviews and low and behold,,,,,,they never used them in any advertising.
Hmm. I wonder why?
No really, Smart pots dry out too fast.
Smart pots concentrate the roots into a tight ball, thus they do not absorb the nutrition in the whole pot effectively.
This concentrated root ball also causes the "umbrella effect".
This is where the water/nutrient (if you so use a liquid nute) to simply run around the root ball and exit the pot into the tray....
You have to leave the pot in the tray to pick up that run off to get the whole pot/root system damp. And it don't work that well to do it.
Hell what about what leech's out, is that good nutrition for the plant?
The root tips are important. Pruned tips take time to recover!
Nope, sorry,,,,,Smart Pots ,,,,, Aren't!
Doc
