Crochet an airpot planter from plastic bag 'plarn'

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Plarn, if you haven’t heard of it before, is yarn made by knotting together strips of old plastic bags, which can then be knit or crocheted. Who doesn’t have a stash of plastic grocery bags in a cupboard or drawer? (I rustled some up for this project and found I still had bags from shops in Leeds – a city I left 5 years ago!!)

Lots of people use plarn to make sturdy tote bags and market bags. This is a great idea – turning a lot of plastic bags which would have ended up in landfill and converting them into something which has the same purpose, but is stronger and can be used again and again, which cuts down on needing new plastic bags – recycling, re-using and reducing

I’ve started gardening on my balcony recently, and came across the ‘air-pot’ system. Air pots are a kind of planter with an egg-box-like surface and lots of holes. Normally in a potted plant, when a root hits the side of the pot it is deflected and roots start to grow in a spiral round the pot. Over time, these roots grow into a dense mat which does not absorb water and nutrients very well, and may be prone to rotting and disease. The design of the airpot directs roots, when they reach the edge of the pot, to poke through the holes, where of course they dry out and are ‘pruned’ by the air. This encourages new roots to grow from the base of the plant, so instead of a thick unhealthy coil of roots at the bottom of the pot you end up with a mesh of new healthy roots spreading throughout the soil. Unfortunately the air-pots are rather expensive, especially if I wanted some shipped to Japan.

It occurred to me that crocheted plastic bags would have a similar effect – the rounded bumps of the stitches would encourage root tips to grow through the holes between the stitches, while the holes would give really good drainage and the layers of plastic would insulate the roots from extremes of hot and cold. So I give you, the crocheted plarn planter!

You’ll need:

• plastic bags – I made a pot 5in in diameter and about 4in tall, which took 10 bags.
• scissors
• crochet hook – plarn is tough on the hands so a hook with a chunky handle will be better

To make plarn, fold a plastic bag and cut into strips around 1 inch wide (you can cut thick bags a little narrower and thin bags a little wider to get a fairly consistent gauge). You are cutting your bag side-to-side, so each strip will actually be a loop. Thread one loop through the previous loop and through itself to attach them together.

You don’t need to make all your yarn at once – you can just add on new loops as you go.

Crochet the plarn as you would any other yarn. You will find it is rather hard on the hands and wrists, so take regular breaks, and use a hook with a chunky grip (I improvised one from a strip of scrap fabric and some tape). If you are having trouble catching the plarn with your hook, twist it a little to make the strips more yarn-like.

To make a 5in pot:

Make a magic ring, ch1, sc7 in ring, join with slipstitch
Ch1, sc1 in same stitch, sc2 in each stitch, join with slipstitch
Ch1, sc1 in same stitch, sc1, (sc2 in next stitch, sc1) 7 times, join with slipstitch
Ch1, sc1 in same stitch, sc2, (sc2 in next stitch, sc2) 7 times, join with slipstitch
Ch1, sc1 in same stitch, sc3, (sc2 in next stitch, sc3) 7 times, join with slipstitch
Ch1, sc1 in same stitch, sc4, (sc2 in next stitch, sc4) 7 times, join with slipstitch
Ch1, sc1 in same stitch, sc5, (sc2 in next stitch, sc5) 7 times, join with slipstitch
Work in plain single crochet until your pot is the desired height. Join with slipstitch and weave in loose end.

To make a bigger pot, work more increase rounds before switching to plain single crochet – you need to make eight increases per round.

I’m going to sow some mixed lettuces in mine – I’ll let you know how they turn out!

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