Trial: Wick-irrigation systems for growing veges

This is a trial - trying to see what works (and what does not)
You’ll need four things. Here is what we are doing…

I am trialing a gardening system. It is for people with injured knees or sore back. Those who cannot bend as well as they used to be able to. It is also for busy city folk who have little time or limited space for a garden. This system is for those who need to leave their garden for five days to go on a trip or to hospital.

So Far

This is what I up to so far.

My trial involves a few simple concepts. First, I’m using containers. This allows me to sit in an outside chair and tend my plants. But this might change.


Next, it must be mostly self-watering. I have decided to explore watering by capillary action. In my capillary action trial, the water travels along inside a rope to the plant.

I’m conducting my trial system on our deck because I like the view while I work.

It gets really hot on the deck and the plants need to self-water.

Capillary action draws water up the rope. I decided to focus my trial efforts using a water supply in adjacent reservoirs (in this case, used plastic containers).

I trialed some cheap nylon rope to see if water moved through it. It worked perfectly so I did not test out other ropes.

I recommend using non-rotting fiber such as synthetic yarn, acrylic or nylon venitian blind cord, or strips of nylon stocking.

Capillary action pumps the water.

Do not be concerned about the height of the water. The wick will enable the water to travel upwards and down wards. Heights do not matter. It is drawn by capillary action, not a siphon or gravity.

I discovered I can water two plants from each milk bottle. Two wicks from each bottle.

I’ve learnt that plants can be watered by a water bottle buried next to them. The wick can come out the top of the bottle and across to the plant.

A loose weave rope draws more water.

If my plant needs more water, I can double it by using two wicks. This doubles the flow and quantity.

The wick must be long enough to reach the bottom of the reservoir.

I have also learned to soak the wick in a little detergent water first. The detergent acts as a wetting agent and increases capillary action.

Nutrients can travel to the plant up the cord. I have yet to learn if this will block the cord later on. Tell me if you know.

I fill the reservoir through the large top hole. I’m experimenting with a small side hole close to the top for the wick to see if this will make filling easier.

I learned more here.

How we made this simple system

You will need:

  • Used flute-board
  • Old milk container
  • Nylon rope
  • A nail

* Thanks to Simeon, my 17 year old son, for demonstrating how to make it.

Measure your rope.

It must reach the bottom of the bottle, exit the top of the bottle then be long enough to reach deep into the potting mix around your plant.

Cut several to length.
Cut them before you go outside.

Cut your flute-board into several strips.

Height = taller than your bottle.

Width = just wide enough to fit into your bottle.

Cut a small slit in one end of the flute-board. This is to hold the rope near the bottom of the bottle.
Use a craft knife.
Put the flute-board into the bottle. Slit end down.
It needs to touch the bottom.
The flute-board is taller than the bottle.
Drill a hole through the bottle.
The hole goes through the flute-board too (not your finger).
The holes size is the same size as the nail. The nail fits into this hole. I selected a hole size so the nail has a tight fit so the nail would not shake out.
Fit the nail in the hole. It holds the flute-board in place.

Dismantle it. Pull out the nail. Remove the flute-board.

Next you want the above configuration with two wicks (rope lengths) in the slit. As follows:

Pull one end of your rope into the slot. This will hold it.
No need for a knot.
Pull the end of a second rope into the slot. Push the flute-board into the bottle. Then secure it with the nail.
Push the flute=board into the bottle, slot end first.
Push it right down.

Re-insert the lock-nail.

Now both wicks reach the bottom of the bottle. They cannot curl upwards.

Install between two plants.
Use a tool to push the wick deep into the potting mix.
I use a strip of flute-board as a tool to push in the rope.
The water will travel. I am concerned about loss to evaporation, especially with low pots. Exposed rope must be minimized.
Fill each reservoir (bottle). I will trial using liquid fertilizer.

I will be trialing this over the next weeks. It seems good and works so far.

Improvements & Tweaks

3 days later…
This was unexpected. I thought the flow would be too small. However, it flowed out at 300 ml over 2 days. That’s 150 ml per plant per day. This is too much water for the little seedlings. They require about 80 ml per day. So I have to throttle back the flow somehow.

Next day …
This is how I will try to reduce the flow. I could use a thinner woven cord which would be more constant in resultant flow. This is really cheap rope from The Clearance Shed at The Base.

I chose to bind the wick with something to reduce the flow a little. Results to plants may vary. Perhaps it will stop it altogether. Not the best of ideas. Still, I’ll see how this goes.

A day later…
I accidentally pushed one nail too low. Instead of exiting the bottle the point entered into the handle cavity. This is much improved as there is no sharp protruding nail to scratch myself on.

I will do this from now on!

One week later …
Overwatering. My plants are getting too much water.
I am going to change the system so it waters from below.
The wick needs to enter from the base.

Currently I think this needs to be even simpler. To use less materials.
The basic wicking system might be able to be made with hose. Water, under very low pressure, flows up the hose past each planter bag. The wicks can run from the hose and up into each planter bag from the base.

Could a rubber seal around the wick prevent water leaking from the hose. Foam rubber stuffed in the hole around each wick.

Any ideas anyone?



Water flow height control

I am trying to control where the water enters the potting mix. This not flow. It is about entry point height. Too high and the top half of the potting mix is too wet. I want water to rise from the bottom of the pot, not from the top. So I added a short length of old hose. The wick is inside the hose.
I pushed the hose into the potting mix, making sure that some of the wick extends beyond the end of the hose. Water enters the pot lower down, only where the rope is in direct contact with the potting mix. I hope this will mean the top half of the pot will be drier.
To have water enter even lower in the potting mix, I will push the hose deeper in to the pot. This means water flow by capillary action will not occur near the top of the pot. The depth of hose controls the place where water will enter the pot. For a higher entry point I will pull the hose up high, thus exposing more wick. This is a trial. I hope this works. We will see what happens.

It has not worked out perfectly. Some plants preferred less constant water. Some developed root rot. It is a partial solution. Good for short term. This still needs more work to be a success.

Henk Ensing

Self reliance & low-tech irrigation website guy