Build your own Autopot/Quad Grow System

Self-watering at a fraction of the cost

About ten years ago I set up some self watering system experiments, the one that’s still in service today has been used for bush beans, growing on blueberries, Asian greens and whatever else that wasn’t the target of pests - the original site was set up to self water 55x 11 litre pots, basically 5 rows of 11 pots.

Now it’s been dismantled and reduced to two rows of 20 in the polytunnel that I used as a test for growing some aubergines and peppers last year - and one row outside to help keep a load of Japanese wineberry, Boysenberry and Raspberry cuttings growing on.

The problem I see is that the cost of four plastic pots and a reservoir is over £100 for a 4 pot Autopot system and £60 for a 4 pot Quadgrow system - so your first harvest will be more expensive than a pack of vegan friendly gold leaf covered peppers and you could build a 20 pot system for a similar price.

You’ll need a flat surface to mount the system on whether you buy one or make one - pavers are an ideal platform, but a deck, patio or concrete surface will do as long as when it’s filled, the water reaches all the wicks.

For a basic system, all you need is a watering can to feed the reservoir - but you can install floats or a hose timer to keep it topped up - in one iteration I had a four way splitter attached to the stand pipe, so 44 pots could be watered simultaneously in less than a minute if there wasn’t enough rain - however in the polytunnel I prefer the watering can because I like to mix my own JADAM feeds and fertilisers and I want to check on each plant regularly for diseases, pest and harvests.

The basic system requires some time but almost zero DIY skills …

2 pieces of CLS 3”x2” wood

1 piece of gutter (a few cm longer than the wood so that the end caps fit)

2x gutter end caps

Large pack of 19mm Tek Screws

A row of 11 litre pots

A hole saw & drill

A small roll of capillary matting to make the wicks

What you’re aiming for should be a piece of gutter with two end caps sandwiched between two pieces of CLS wood and held level with the top of the wood with self-tapping Tek screws.

On top of the wood should be around 11 litre pots that have a hole large enough for the capillary matting wicks to be rolled into a loose tube to pass through.

The wick should be tapered and have enough left to to sit in the gutter and reach the top of the pot when they are filled with soil.

When I fill the pots with soil and compost I hold the wick in the centre and put a few handfuls in at a time so the wick stays central - when they’re full the last couple of cm are still proud of the surface so I can move them slightly to one side and have the plants in the middle as normal.

I always use square pots for everything because round ones waste so much space - These are pretty ancient pots and I used a 65mm hole saw, but the size of the hole just needs to be large enough to pass a piece of rolled capillary matting through.

Tapered wick, height of the pot plus several cm extra to sit in the water channel you’ve built.

Two rails either side of the gutter - 18 Tek screws and two end caps to finish the reservoir.

Close-up of screws and end cap - there’s enough room to put a hose or watering can by the end cap to fill the reservoir.

Two sets of pots filled and in situ on two sets of rails and all levelled so that the reservoir can be filled from either end and the plants all receive water from a single source and whatever liquid fertilisers or KNF inputs you prefer can be put in the reservoir and wicked up.