Thanks gardengal, math makes me dizzy. For those of us who can remember the pre-plastic days with the straight sided metal cans that every can had to be cut down the side to get the plant out, who longs for the good old days? A one gallon metal can was able to hold one gallon liquid and so they were referred as "one gallon containers". When Plastic pots were made with a taper that allowed the plant to slip out, the pots to be able to stack together, we were all so grateful, who cared that they no longer held a gallon. Someone filed a complaint a few years ago with the weight and measures people that they were paying for a one gallon measure that was not "one gallon". Now you will notice they refer to them as "trade one gallon", thus avoiding the claim of "not containing one gallon". Al

Al- Thanks for reading my long post and for the compliment. Ronalawn- been there on the wrong side of the road, making left turns was the worst for me. By the way, speaking of the weight of a gallon of water..... I believe a US gallon of water weighs 8.3 pounds (at least it's a little closer to your 10 pounds, which is indeed the weight of an Imperial gallon.) Also, a liter weighs 2.2 pounds. There are 7.5 U.S. gallons in a cubic foot of volume. So, 5 gallons equals 2/3's of a cubic foot. (2/3 x 7.5 = 5). A cubic foot of water weighs 62.5 pounds. And just for grins I'll throw in... Watering Your Garden: To cover 1,000 square feet with an inch of water takes 625 gallons. One Gallon per minute (gpm) = 1,440 gallons per day. It takes 10.4 gallons every minute, to apply one inch of water over 1,000 square feet every hour. Gallons divided by minutes x 8.03 = cubic feet per hour. Gotta go water, it's HOT!!! Rebecca

There is potential for zinc toxicity if you plant in galvanized pots ....... especially if soil/water pH are on the acidic side. There is plenty of potential for you to have complete control over your plants ht and width, but controlling its mass requires a little more finesse. IOW, your trunk is going to get thicker and thicker over time. You'll need to learn how to maintain your plants root system, because vitality, growth rate, and branch extension are all negatively affected by root congestion. At the approximate point where root congestion progresses to the stage where the entire root/soil mass can be lifted from the pot intact, limitations related to said congestion start affecting the plant and become progressively more limiting until there isn't much left of the plant. Usually, the plant succumbs to insect infestation or diseases as congestion worsens. BTW - potting up (as opposed to repotting, which includes root pruning) is not a cure for root congestion. It temporarily/partially leaves some of the associated limitations, but ensures those limitations will ALWAYS be in play until such time that you or someone familiar with root work actually gets their hands in the root mass and corrects the congestion. Al

How large a container ‘can’ or ‘should’ be, depends on the relationship between the mass of the plant material you are working with and your choice of soil. We often concern ourselves with "over-potting" (using a container that is too large), but "over-potting" is a term that arises from a lack of a basic understanding about the relationship we will look at, which logically determines appropriate container size. It's often parroted that you should only move up one container size when "potting-up". The reasoning is, that when potting up to a container more than one size larger, the soil will remain wet too long and cause root rot issues, but it is the size/mass of the plant material you are working with, and the physical properties of the soil you choose that determines both the upper & lower limits of appropriate container size - not a formulaic upward progression of container sizes. In many cases, after root pruning a plant, it may even be appropriate to step down a container size or two, but as you will see, that also depends on the physical properties of the soil you choose. It's not uncommon for me, after a repot/root-pruning to pot in containers as small as 1/5 the size as that which the plant had been growing in prior to the work. Plants grown in ‘slow’ (slow-draining/water-retentive) soils need to be grown in containers with smaller soil volumes so that the plant can use water quickly, allowing air to return to the soil before root issues beyond impaired root function/metabolism become a limiting factor. We know that the anaerobic (airless) conditions that accompany soggy soils quickly kill fine roots and impair root function/metabolism. We also know smaller soil volumes and the root constriction that accompany them cause plants to both extend branches and gain o/a mass much more slowly - a bane if rapid growth is the goal - a boon if growth restriction and a compact plant are what you have your sights set on. Conversely, rampant growth can be had by growing in very large containers and in very fast soils where frequent watering and fertilizing is required - so it's not that plants rebel at being potted into very large containers per se, but rather, they rebel at being potted into very large containers with a soil that is too slow and water-retentive. This is a key point. We know that there is an inverse relationship between soil particle size and the height of the perched water table (PWT) in containers. As particle size increases, the height of the PWT decreases, until at about a particle size of just under 1/8 inch, soils will no longer hold perched water. If there is no perched water, the soil is ALWAYS well aerated, even when the soil is at container capacity (fully saturated). So, if you aim for a soil (like the gritty mix) composed primarily of particles larger than 1/16", there is no upper limit to container size, other than what you can practically manage. The lower size limit will be determined by the soil volume's ability to allow room for roots to ’run’ and to furnish water enough to sustain the plant between irrigations. Bearing heavily on this ability is the ratio of fine roots to coarse roots. It takes a minimum amount of fine rootage to support the canopy under high water demand. If the container is full of large roots, there may not be room for a sufficient volume of the fine roots that do all the water/nutrient delivery work and the coarse roots, too. You can grow a very large plant in a very small container if the roots have been well managed and the lion's share of the rootage is fine. You can also grow very small plants, even seedlings, in very large containers if the soil is fast (free-draining and well-aerated) enough that the soil holds no, or very little perched water. I have just offered clear illustration why the oft repeated advice to ‘resist pottting up more than one pot size at a time’, only applies when using heavy, water-retentive soils. Those using well-aerated soils are not bound by the same restrictions. As the ht and volume of the perched water table are reduced, the potential for negative effects associated with over-potting are diminished in a direct relationship with the reduction - up to the point at which the soil holds no (or an insignificant amount) of perched water and over-potting pretty much becomes a non-issue. Al