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joe1980_gw

Pot size for Ficus Alii

Joe1980
9 years ago

Hello all, I am looking for an idea of what size pot to move my ficus alii to. Currently, it is in gritty mix, and doing well, but I think I over potted it a couple of years ago. This tree was a rescue a few years back, on its way to the dumpster at the plant shop. Anyway, its about 4 feet tall from the top of the soil line, and the trunk is about 1.5" in diameter. The foliage is pretty full and lookin good. When I scratch into the potting mix, I have to dig for a while to find roots, and after 2 years, I suspect that means I WAY over potted it. Its in a 14" pot, and with gritty mix, its unbearable to move.

So, I am looking for your opinions on potting down, and what size I should go to. I have a couple of thick roots left from my original rescue work, so those will be going away during this pot down. Thanks!

Joe

Comments (5)

  • tapla (mid-Michigan, USDA z5b-6a)
    9 years ago
    last modified: 9 years ago

    If the gritty mix was made correctly, you couldn't have over-potted. Plants in soils that hold little or no perched water, like the gritty mix, can't be over-potted because there is no 'soggy factor' to rot roots or limit root function. For growers that understand how to manage their plants' roots, appropriate pot size is determined almost entirely by soil choice. As the amount of perched water a soil holds decreases, so does the need to pay attention to how large the pot can be and still allow the grower to optimize vitality.

    It's difficult to guess at how small your pot can be after root work, but if I was working on a 1.5" tree in a 14" inch pot, I'd probably be able to fit it into a 10" pot fairly easily - not that I WOULD, but I COULD. If I wanted the tree to grow fast and put on weight, I'd prolly prune the roots and move the plant to a bigger pot. If I wanted refinement in the tree (lots of leaves and twiggy branches) I would grow it on the tighter side. I'd still do the root work, but I'd let the stress of fine roots decrease leaf size and internode length. That can be a fine line to walk, though. If you lean too far toward maintaining a compact root system, the plant starts to shed interior foliage, so most of the leaves are concentrated only at the tips of branches, which gives the plant a 'poodle cut' look.

    Your pot might have been larger than it needed to be, but that doesn't mean your plant was over-potted. The term 'over-potting' must be associated with negatives (usually impaired root function or root rot, or poor appearance due to the root issues) or it's difficult to justify use of the term. Not chiding you - just musing.

    Al

  • tapla (mid-Michigan, USDA z5b-6a)
    9 years ago
    last modified: 9 years ago

    BTW - the question of 'appropriate pot size' comes up so ofter, I saved this from something I wrote & posted tro a thread somewhere along the way:

    Choosing an Appropriate Size Containersize>

    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

  • Joe1980
    Original Author
    9 years ago
    last modified: 9 years ago

    The problem I've found is that the top dries out, while the bottom is still damp. The pot seems too deep, which comes with larger pot size. As noted, after 2 years the pot is nowhere close to filled with roots. I picked up a 10" pot yesterday, and will give that a shot if need be, but once I uproot the tree, I'll ultimately decide. I'm not looking for rampant growth anymore either, as I'd like to avoid it getting too tall. I think the 10" pot will look more proportional than the giant 14" pot it's in. Thanks for the information as always.

    Joe

  • Joe1980
    Original Author
    9 years ago
    last modified: 9 years ago

    Well, it's at home in a 10" pot now. I did some pretty extensive work, removing a couple of roots that were 1+" in diameter, which took a fair amount of feeder roots with them. I don't think I removed more than 1/2 of the root mass, but pretty close, so I'm a bit nervous about how it'll react. I did cut a few smaller branches out that were not symmetrical with the rest, but I fear it's gonna get mad at me and throw its leaves on the floor. Is there any special treatment I should give it at this point, or just ride it out?

    Also, maybe this is something for a separate thread, but this tree brought about the problem. I seem to have trouble watering large pots with gritty mix. Earlier this week, I carefully applied water over the surface of the 14" pot, doing so as evenly as possible, with a turkey baster, so as to do it slow. After a bunch of water filled the tray, I scratched down 1" and the mix was bone dry. This is what ultimately pushed me to a smaller pot, where I can now water like the rest......plug the drain hole, fill 'er up, unplug the drain hole, and drain it out.

    Joe

  • tapla (mid-Michigan, USDA z5b-6a)
    9 years ago
    last modified: 9 years ago

    All soils dry from the top down, and it's not a problem because the roots in the upper quarter of the pot primarily serve to anchor the plant and act as plumbing - to transport water and nutrients and serve as a storage place for photosynthate.

    Al