Read about Craig Presnell


Revolutionary new pot provides
Green Solution
to Transplant Shock
of Marginal Plants 

by Craig Presnell, Florida USA
Click images to enlarge

Getting marginal plants to market with minimal transplant shock has always been a major hurdle growers faced. Twenty years ago, when we started carrying water garden plants, the industry relied largely on wild-collected stock and transplant shock was a way of life, so the retailer was left with little alternative other than to cut the plants back, pot them up and wait for them to re-grow to the point they were saleable.
The first major innovation to resolve the problem was to expand tissue culture production to include at least the most popular marginal plants. Besides taking pressure off native plant populations, tissue culture offered growers a steady supply of large growing marginal plants that could now be grown on in the black plastic net pots that were a staple for potted aquarium plants and shipped for little more cost than that for a bare root plant. The limitation with tissue culture was that it was not available for every marginal plant, especially new introductions, so we added vegetative propagation from our stock plants and seed propagation and were then free from a reliance on collected plants … and life with the 2” (5cm) net pots was good. 

2” (5cm) net pot

But not perfect. We knew from experience that for optimal growth, the plants had to be removed from their net pots for the final install and, as that removal damaged roots, the retailer was once again faced with transplant shock; granted it was not as severe as that seen with the collected stock, but still a consideration.

Not only were we bothered by the fact that transplant shock was still an issue, it seemed counterintuitive that, for a “green” industry, the best solution to date was a plastic pot that then has to be discarded. To overcome the two conundrums, we tried peat pots but they could not stand up to the constant saturation needed to grow marginal plants and it seemed there was no good solution to the plastic pot.

6cm Dot Pot
Late last season, however, we came across a “next generation” pot that was not only biodegradable, but also OMRI certified as organic. Instead of peat and glue, the Dot Pot is constructed of 80% wood fiber from sustainable forestry and 20% peat, and does not require glue in its construction. Our tests show that it can indeed handle constant saturation for far longer than the time required to root plants and, since it is completely biodegradable, there is no labor required in up-potting, since without glue, the bottom does not have to first be removed. It also handles the rigors of shipping with no damage to the integrity of the pot; so this year, we put it into production. 

Net pot vs. Dot Pot
At 6 cm, it is slightly larger than the 2” net pot and, whether it is that the material itself enhances growing or the slight increase in volume of soil it can hold, the increase in vigor and size of the potted plants is surprising. The manufacturer claims growth is enhanced by the porosity of the pot which encourages roots to emerge from any point and not just circle around the bottom. Whatever the case, it is just a bonus to the consideration that, since they can be repotted with the plants completely intact, transplant shock seems to be a concern of the past and discarded plastic pots are no longer heading for the landfills.  

WGI ONLINE Journal Table of Contents

Water Gardeners International
Home | Join WGI | Members' Exclusive | Gateway to Water Gardening