Garden enthusiasts would understand the temporary nature of nursery cans better if they knew more about how plants grow in nurseries. Few plants actually grow in the retail nurseries that market them. They grow in production nurseries, where efficiency is a priority. Nursery cans, which retailers and consumers refer to as ‘pots’, are the most efficient means with which to contain the crops.
Most nursery cans are thin black vinyl. While plants are small, crowded ‘can to can’ arrangement shades the black vinyl so that it does not get too hot from sunlight exposure. Those on the western and southern edges of a crop might get shade from a temporary row of empty cans or a plank leaned against them. As plants mature and need more space, their growing foliage shades the vinyl.
As plants become marketable, they go from production nurseries to retail and wholesale nurseries. From there, they go to new landscapes and home gardens. Only then do they finally escape the nursery cans that they grew up in, to disperse their roots into real soil. The nursery cans have finished their job. Plants can not live in them forever, even if they continue to live in other types of pots.
Nursery cans are efficient, but not necessarily comfortable. By the time they are marketable, the plants that they contain are generally about as big as they can get within their cans. If they get any bigger, their roots will be crowded. If too exposed to sunshine, the black vinyl gets hot enough to cook the roots within. Plants prefer to be in the ground, or at least pots that are more comfortable.
Potted plants that will grow bigger should live in pots, planters or other containers that are bigger than the nursery cans that they grew in. Some will want even larger containers as they grow more later. Annuals and plants that will not grow much bigger are not so critical. However, all potted plants that will not shade their own pots appreciate containers that are better insulated than thin vinyl.
Clay pots, wooden planters and even concrete urns are as practical as they are appealing.
A dressed turkey that is packaged for retail sale in a supermarket is not ready to be eaten right away. If frozen, it must be thawed slowly. It must then be unwrapped; and little bag of giblets must be removed from inside, before the turkey gets stuffed and finally cooked. Although the inexperienced sometimes cook a turkey with a giblet bag still inside, doing so is not the correct procedure.
Plants that are purchased in retail nurseries are similarly packaged in such a manner that facilitates transportation from production nurseries to retail nurseries, and from retail nurseries to home gardens. Their roots are contained in vinyl cans. Larger trees might be boxed. Occasionally, balled and burlapped plants are available. Most trees and vines, and some tall perennials are staked.
Vinyl cans, which are also known as nursery pots, are designed for growing nursery stock in, and containing the stock as it is transported. That is all they are designed for. They are not meant to be used as planters in home gardens. Most young and actively growing plants that tolerate them in production nurseries really do not want to be confined to vinyl cans any longer than necessary.
Even if plants that are brought home from a nursery are to be grown in pots, they should be planted into more appealing pots that are designed for the comfort of the plants within, and not just left in the nursery pots that they were grown in. Clay pots and wooden planters are comfortably porous and better insulated than thin black vinyl that gets dangerously hot if directly exposed to sunlight.
Alternatively, nursery pots can be shaded and obscured within slightly larger pots, within groups of other pots, or by settling them into shallow shrubbery or deep ground covers temporarily. Plants that are big enough to provide their own shade are likely too big for their nursery pots. Invasive plants like mint are often grown in nursery pots that are buried almost to the rim in the ground, although mint eventually escapes through drainage holes. It is good to know the limitations of what nursery pots are useful for.