Indoor Gardening and Houseplants: Myth: This Plant Likes/Prefers to be Root-bound , 1 by tapla

tapla wrote:
We know with certainty that root constriction slows growth and saps vitality, even in palms. For this reason, commercial growers try to remain diligent about bumping plants before the roots become congested to the point root/soil mass can be lifted from the pot intact. IF a grower feels that a particular plant grows better when grown tight, you can be fairly certain the reason lies in the limitations imposed by a soil that ensures a lot of potential is left lying on the table. The only reason the plant seems to grow better with tight roots is because a small container speeds the return of a favorable volume of air to the soil, where the limitations imposed by the soil would be much greater in a container where a soggy layer of soil at the bottom of the container limits root function.

If you eliminate the limiting effect of the soil by switching to a soil that doesn't support perched water, all else being equal you can achieve the same growth rate in containers as plants in situ. This remains true until about the point where the root/soil mass can be lifted from the container intact, at which point growth begins to slow and vitality wane. If you eliminate the ill effects of a soil that holds enough water that it becomes limiting, you can grow the tiniest palm in a 55 gallon drum and achieve growth far superior to its counterpart with congested roots in a smaller container.

If Mother Nature felt that palms or any other plant grew better with tight roots, she would have arranged for root systems to grow in tight little knots directly beneath the stem. Such is not the case, however. There is no physiological reason to believe that tight roots produce better growth or healthier plants, in fact, the contrary is true and there is plenty of evidence to support it. Tight roots simply help to eliminate the limiting effects of an overly water-retentive soil, but in essence that is trading one limitation for another - unnecessarily.

If you switch to a soil that supports no/very little perched water so impaired root function due to excess water retention is off the table, you'll see exactly what I mean. We can actually provide better nutrition in containers than plants normally get in situ. If we do that, and make sure light/temperature are not a limiting factor, containerized palms still grow far more slowly than their in situ counterparts. For what reason? Root congestion.

Al



This message was edited Jun 17, 2012 11:12 AM