You raise the perched water table by doing this and increase the chances of root rot.

Whenever I am using too big a pot, I just fill it to the point I need, and when the plant needs a bigger one, just pull it out later and backfill it to the appropriate height. I get a lot more use out of the pot.

Why would you want to take a perfectly good 20 gallon pot and reduce it to 16 gallons.

Steve

Yes, absolutely that is one way of doing. I like the use of the upper part of the pot the much wider part for citrus. For figs i really don't care i never have a problem with those guys.Rootrot what is that? Premium treated tree's, premium looking tree's for me anyway.

Steve, Vlad you guys are correct, i should't post a dumb thing like that. I promise to do better next, if there is a next. My tree's tells a different story.

I have a customer that I do his potted plant arrangements. He has me cut down his pot sizes just like you showed us. So this is something I have been doing for 20+ years. I have tried to convince him that it is better to use the whole pot for root room and less hard surface areas for slimy root rot to develop. I cut down one of my pot sizes by installing a screen over gravel. That worked well but it was hard getting the roots out of the screen fabric. your method will leave cinder walls of root and that will make re-potting hard for you.

Good question though. This allows other to share their opinions and why that other will see. They will be more information to use in their own decision to reduce or not.

Steve

I've done this with my potted roses for 10+ years without a problem. However it is time to repot and I do have an improvement for the next round of pots... to make it easier to up-pot. I will put capped, vertical tubes in there and simply pull them out and backfill to allow the roots to grow.

I do not see how putting cans into the pot and with all that space between them could possibly raise the water level.

May be I will pipe in and say that I do something like what Bob has done very often. What this method does actually reduces the perched water table or PWT very effectively and will reduce root rot damage. Let me explain.

Consider that effectively the bottom of the pot is the top of those overturned pots. The small gaps between the pots will be filled with soil and go all the way to the bottom of the pot. But they will be effectively small "pipes" of soil. They will act like wicks for the main body of the soil. Looking at it differently the perched water table is always measured from the lowest point of the soil and so most of the perched water will be in this very small volume of soil. This will keep the upper bulk of the soil less moist and more aerated.

Roots will eventually grow into those "pipes" of soil but they are not consequential since the volume of soil they occupy will be very low compared to the rest. From PWT point of view the bottom is the bottom of the pot.

On the other hand the screen over gravel method does not do anything to the perched water. From PWT perspective the bottom is the soil/screen interface.

On the other hand if the target is to maximize soil volume then this method obviously does not achieve that. But if the bottom of the pot is consistently wet then that zone is effectively un-inhabitable for roots so the advantage may not be realized. For figs or any fast growing plant with high water demand this is less of a concern since their roots will suck that water out in no time.

I assumed that he used oil dry as the bottom layer but upon re-reading the original post it is not clear what goes in the bottom. If he is putting soil between the coffee cans, then I am not sure whether the perched water table would be affected although I suspect it would still be raised.

This discussion appears to have turned out to be a really deep topic.

Steve

Here we go,first i usely buy about 16 bags of pinebark, the smaller stuff, not nugets. 10 bags i run through the fire department chipper, that last about a 1/2 hour.

Around the coffee can i use regular pinebark,right up to the top of the cans, then everything else, do not use peatmoss because it is already in the pottingsoil. I mix-in dolomite lime and i also mix Espoma citrus/avo fert,which is good for up to a couple of months, this stuff is a mild citrus fert. These containers are in my shop to warm-up for up potting in February.

What I said originally stands.

Well you do with what you like, I believe that there are many many agree with you. I am a classic cheapskate.You guys are more smart. If you tell us or me what you do I probably still do things my ways,sorry.

Bob I have had the best luck with a soil mix made from 50% dirt dug from my back yard and 50% compost from my compost maker. Any one here will tell you and me that my formula won't work and will kill my citrus trees.

6 feet tall

3.75 feet tall in 30 gallon sprouted 1-7-13. not 1-7-12 shown in picture

I agree with doing what has worked well for you. With my customer It would be cheaper to buy more soil then pay for my time to locate and bury 25% volume space takers. My plants weigh to much with garden soil so I use a 2-2-1 Pine bark-compost, perlite.

Steve

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Vlad: It depends on how structurally similar or different the two soil mixes are. If you compare 511 and 500 (as it seems like what Bob may be doing) then they are more similar than different. If there is a screen or any other barrier in between then they will behave independently otherwise they will behave more similarly.

The ingredients are right there for you to read, pinebark in the wheelbarrel, oildry, ,Sunshine perlite( coarse), Ecoscraps potting soil.Dol..lime and Espoma.

Vlad has an issue with persimmonbob but not me, i think he likes me. He reads too much.