Plants grown in pots suffer, science finds…
That growing plants in pots is not ideal for plant health doesn’t come as a surprise to anyone with a little experience and common sense… (think foot binding). In this recent article from BBC (below) we are offered some empirical scientific support for this claim.
Root-bound plants will always be more prone to illness and disease and will have a greatly limited lifespan. I try to avoid purchasing rootbound plants at commercial nurseries. Of course, this is difficult as virtually all plants sold in commercial nurseries are rootbound. In fact, (correct me if I’m wrong) I believe it is illegal for commercial nurseries in the US to sell a plant unless the whole pot is filled with roots (rootbound). For those of you interested in a better alternative, there are a few companies out there selling containers designed to help avoid root-binding/root circling (as much as possible).
Rootmaker containers are “designed to promote root branching and new roots at every phase of nursery production, whether above-ground, in-ground, or even in-pot. This results in a root system that has a greater surface area than conventional production, and therefore achieves greater efficiency in the absorption of water and nutrients, an increase in growth rate, establishment, transplant survivability.
Another one I have recently become aware of is the Air-Pot, from The Caledonian Tree Company… The Air-Pot, made of recycled HDPE, is cylindrical in shape with a perforated sidewall, which is textured like an egg carton. There are no flat surfaces to deflect roots and start the spiralling process. The inward pointing cones direct the root towards the hole in the outward pointing cones where the air density in the soil is too great and therefore the apical cells at the very tip of the root dehydrate, or are air-pruned. See website links for more.
Here’s the BBC article…
Stunted Pot Plants Can Never Reach Full Potential
Plants grown in pots never reach their full potential, images of their roots show.
A medical imaging technique called magnetic resonance imaging (MRI) has been used by researchers to capture plant pot root snapshots. The pictures reveal that the roots “sense the size of the pot” and restrict the growth of the plant.
The findings have been presented at the Society for Experimental Biology’s annual meeting in Salzburg, Austria.
Lead researcher Hendrik Poorter, from the Julich research institute in Germany, told BBC Nature that as soon as he saw the results, he re-potted all of his houseplants. “I thought, you poor guys, what have I done to you?” he recalled.
…. “The most surprising thing is that there seems to be no end to the pot limitation,” explained Dr Poorter.
“For every plant species we looked at, pot size was the factor limiting its growth.”
Read the full article at BBC Nature…