Universal Sub-irrigation Platform

 

With this universal sub-irrigation soil wick platform, you can convert just about any watertight container to a sub-irrigation (aka self-watering) planter. I use it here for demonstration purposes in an inexpensive plastic pail to grow peppers on my fire escape. The insert will work in any watertight container. Simply cut it to fit the shape of the container you're using. 

You can use this simple and inexpensive method to grow any type of plant (indoor or outdoor) in any type of container from terracotta to ceramic to metal. Don't believe the well perpetuated myth that you need a container with a drain hole. It is simply not true and you can prove it to yourself.

A good way to learn about sub-irrigation is to make some recycled pop/soda bottle planters and use them for both decorative indoor plants, herbs and vegetable starter plants. Be sure to measure the water and allow the reservoir to empty before refilling.

This method will work well for both indoor and outdoor use. For outdoor use, it’s a good idea to drill an overflow hole in the planter just below the platform level. When it rains, the excess water will then drain out without flooding the planter.  

All you need is a box cutter or sharp paring knife. You don’t need power tools other than a drill for the overflow drain hole for outdoor use.

The platform is made of expanded polystyrene (EPS) insulation board just like this planter box. You could also cut the platform from a 12" vinyl floor tile. The objective here is to use an easy to cut material that doesn't require power tools. Use scissors type pruners or tin snips to cut vinyl floor tiles. 

You can even use these platforms to convert clay pots to sub-irrigation. Plug the drain hole with caulking, coat the inside with tree wound paint, make a platform to fit and you’re all set.

There’s now no reason for using clay pots with drain holes and saucers. They waste water and retard plant growth compared to sub-irrigation. They are most definitely not a green product.

The claimed benefits of clay pots are a Martha myth. Admittedly, they look nice outdoors and now you can have the best of both worlds.

Comments

[Matt]

This is by far the most simple and elegant design I have seen. Thank you for posting! My only question now is where can I get EPS? Is it different from EXTRUDED polystyrene? What about Styrofoam?

[Greenscaper Bob]

Good questions Matt. I should have covered them in the post. I bought a package of 3/4" "Panel Foam" EPS insulation board at Lowe's for about $7. There are six (6) 3/4"x13 5/8" x 48" boards per package.

Styrofoam is a Dow brand name. Read this about the difference between styrofoam and EPS.

http://www.grist.org/advice/ask/2003/02/06/umbra-styrofoam/

Keep your eyes open and you will likely find some EPS boards to recycle from trash.

A thinner material would be better for smaller containers. I've used vinyl tile for these. It's easy to cut. You need a drill, however, to make holes.

I used vinyl tiles to make the platform in this planter box.

http://www.flickr.com/photos/greenscaper/1111831774/in/set-72157604071874390/

[salvia71]

how do you know when you have filled the resevoir ?

[Greenscaper]

If you have drilled an overflow drain hole this is one way.

Excerpt from above post.

"This method will work well for both indoor and outdoor use. For outdoor use, it’s a good idea to drill an overflow hole in the planter just below the platform level. When it rains, the excess water will then drain out without flooding the planter. "

When using any sub-irrigation planter with a fill pipe it's a good idea to use a piece of clear 1/4" plastic tubing as a pipette. Insert the pipette tube into the fill tube so that it touches the bottom of the planter. Hold your finger over the top end of the pipette tube and lift it out of the fill tube. If there is water in the reservoir you will see the water level indicated in the bottom of the pipette tube.

[Rasajan]

L.S.

Somewhere it was explained that Polystyrene is a "bad" plastic, to be avoided in plant growing.

But what about the EXPANDED-Polystyrene separation board? Is that any different?

WKR