You might want to try one of the plant categories....Tree Forum, Shrub Forum, etc. whichever is appropriate.

Josias,

I chanced on your question today. Where I live in the States we have suffered months of above 80% humidity and daily temperatures over 100 degrees. It has been brutal! Please allow this old timer to walk you down a rather convoluted garden path of experiments done over the years re your question.

The geotextile fabrics first came on the market in the early 1970's. I was able to trial them in many ways due to my profession. I found the fabric could easily be stitched on a regular sewing machine and also glued together with waterproof glues. So, I was making 'soft pots' long before they were introduced commercially. Abandoned the idea after a few years as I did not see much improvement in plant growth. I have checked out commercial soft pots in stores and read comments that they do not hold up well, etc. Whatever. My geotextile potted root pruning experiments went on the back burner. Until very early spring this year.

I oversee and advise a Community box garden. An interesting exercise. Weeds, blights, neglect and insect problems appear throughout the garden. Frustrated gardeners! I am always looking for organic problem solving methods to improve the situations. This early spring, by chance, I was walking through the nursery section in one of our major 'box' stores. Placed high on a shelf were a few rolls of black paper about 3' long named WEED-X . A bit of instruction reading indicated that this organic 100' by 3' roll of flimsy appearing paper product was permeable and meant to be spread on the ground under mulch to prevent weed growth...and lasted 20 years. Hogwash! This product is too thin to withstand foot traffic. Then I had a thought. What if we cut and placed this paper on of each box garden bed, topped it with soil conditioning mulch and planted and liquid fertilized through it....Bottom line. We installed the paper in every 12' x 6' raised garden box. (Don't give up. I am close to answering your question.) The result is exciting! Very few weeds in the beds. Moisture was retained under the paper. Only disease problem was a bit of early tomato blight on lower branches which we removed. These tomato plants which here-to-for were goners this late in the season are healthy, thriving, still producing. Ditto, other crops.

So, it dawned on me, this permeable, thin paper WEED-X product could be placed inside open weave large laundry-type baskets and large open weave waste baskets as a root air pruning experiment. These I found at a discount store for very few dollars. I inserted cut pieces of the WEED-X paper so they just overlapped each basket rim, secured along the top with clip-on close pins to hold the paper in place until the baskets were filled with soil, black side of the paper to the inside. Cutting to the chase. A very successful experiment! I have never container grown such large and healthy tomato plants and annuals surviving high humidity and torrid temperatures in blazing sun, no shade.

Josias, I have answered your question. May I encourage you to expend the money necessary to purchase and have shipped a 100' roll of WEED-X. Amazon sells it. That roll of paper should last you for many, many years. Basically, your only cost except for scrounging around locating open weave plastic baskets which will last forever. Yes, using the method I have outlined above it is possible to very successfully root air prune container plants in humid conditions. Go for it!

Wow thank you so much for your comprehensive wisdom! I am planning on starting an organics (actually organic!) business here in the tropics and your comment has helped me very much. What tomato varieties did you grow with this method? Please email me: josiasmonkeyman@live.com as I would love to further hear advice from a learned gardener!