Upcycled plant pots with air-pruning in mind – Part 2

In my Part 1 post I explained how I had created my upcycled air-pruning plant pots from 4 pint milk cartons.

Making air-pruning plant pots from milk cartons – I decided to cut different-shaped vents in some of the pots

The next stage was to create some breathable fabric grow-bags to fit into the air-pruning plant pots … the whole idea is to allow air to reach the plant’s roots. In the video where I originally saw the air-pruning idea, they had made use of recycled woven polypropylene shopping bags. As with the containers, I needed something much smaller. And, as before too, I really wanted to use upcycled materials.

Old jogging pants were ideal to make grow-bags to fit the milk carton air-pruning plant pots

My solution for this part of the project was to use some of my sons’ old and worn jogging pants from my upcycling ragbag. The legs of these old cotton pants were just the thing to fit in my air-pruning plant pots.

Measuring and cutting the grow-bag material to size

I measured and cut off the required length, using one of the prepared milk cartons as a guide. This gave me a fabric tube which I closed at one end by simply tying a piece of cotton string around it. And that was it done! I had one simple and upcycled grow-bag ready to insert into its air-pruning plant pot.

I simply tied the bottom of the grow-bag together with a piece of cotton string

In order to maximise the use of the jogging pant material I had available, I did resort to a little bit of sewing to create some of the tubes, but they all ended up roughly the same shape and size. The fabric grow-bags were then carefully inserted into each of the air-pruning plant pots.

I inserted the grow-bag into the air-pruning plant pot and secured the grow-bag to the pot

I had made the tubes long enough so that they would amply overlap the top of the plant pots. My thinking here was that this would prevent the grow-bag from sinking down inside of the pot. To assist further with securing the grow-bags in position I made two small holes in the overlapping part of the grow-bag at either side of the milk carton’s handle using my stitch ripper.

I took another piece of string and threaded this as a doubled length through one hole, behind the carton handle and back out through the second hole. I removed the yarn needle and tied the ends of the string together firmly in a knot. I then created a string loop by threading the knot back through the loop at the other side of the handle to finish it off. As well as helping to secure the grow-bag in place, I thought the string loop might be useful when it comes to fixing the plant pot in place in my back yard.

My upcycled air-pruning plant pots are now fitted with their upcycled grow-bags and ready to be filled with compost. I’ll show you more on my air-pruning plant pots project very soon.

J Peggy Taylor

Upcycled plant pots with air-pruning in mind – Part 1

I was so inspired by the air-pruning video I shared with you a few days ago that I immediately decided to try out this seemingly magic method of improving plant growth. I already had imminent plans for sowing some Sweet Pea seeds as I am planning on training several Sweet Pea plants to grow up and through the crochet jute and willow garden screen that I have also been working on recently. The willow garden screen project is my experimental version of location-specific vertical gardening.

Two rows of jute crochet bind the willow rods in place

As my back yard is only very small I needed to develop some air-pruning pots that would be more size-appropriate than the 5 gallon buckets they used in the video. But I also wanted some containers that would reasonably accommodate the Sweet Pea plants. I have grown Sweet Peas in my yard in the past using moderately-sized containers and with a bit of care they successfully reached their full six-foot height.

A further consideration was that I need to be able to attach some of the plant pots to the back of my yard gate, so lightweight containers with ‘attach-ability’ were additional factors to bear in mind. And, as I frequently do, my preference was to use upcycled materials for this project too.

The solution to my air-pruning plant container conundrum is … four-pint milk cartons! These milk cartons satisfy all of my requirements – lightweight, with built-in handles for ‘attach-ability’, moderately-sized and easily re-designed for their new purpose … and upcycled.

Fortunately, I had a number of these milk cartons readily available as I had saved them ‘just-in-case-I-need-some’ – I’ve made milk cartons into standard-type plant pots on previous occasions. But this time my design plan was rather different.

Making air-pruning plant pots from milk cartons – cut carefully around the milk carton’s original opening, making sure you leave the handle intact

I began by making a large planting hole at the top of each carton by cutting around the original milk carton’s opening. You can see I have cut high above the carton handle to leave the whole handle intact. Around the sides and front of the carton I dipped down a little lower with the scissors to make a reasonably-sized opening to give accessibility.

Next I pondered on the best way to ventilate the sides of the cartons to provide the air-pruning effect. The air-pruning video showed circles cut out of the sides of the 5 gallon drums. I emulated this on the first carton, cutting out relatively large holes all around it.

Making air-pruning plant pots from milk cartons – I decided to cut different-shaped vents in some of the pots

However, I then wondered if different shaped holes would be more or less effective at air-pruning. To test out my curiosity, I have decided to make different shaped holes in some of the cartons. Two cartons have circles, two have wide vertically-oriented ovals and the remaining two have a series of narrower vertical vents. It will be interesting to see if the different-shaped vents in the containers make any difference to the plant growth.

Watch out soon for Part 2 of my upcycled air-pruning plant pots project in which I will show you how I made the fabric grow-bags to fit inside the pots.

J Peggy Taylor