The soil in the chamber will wick fine as long as it's the right mix. As for other materials; the woven cotton rope used for closelines woorks good as does hemp rope. But the best wicking I've seen is made by removing the plastic cover from a disposable diaper and cutting it into strips

The wick material needn't be particularly good at moving water great distances quickly. It only needs to move it a short distance slowly. I would tend to shy away from wicks of natural materials as rot causing biota will eat them up quickly. Some good wick materials are synthetic shoe laces, man-made chamois (100% rayon), the nylon ties from citrus fruit bags, braided polypropylene rope, nylon rope...

Test wick material by dangling it, dry, in a glass of water. If water "climbs" up the wick several inches over several minutes, and it is resistant to rot, it's suitable.

Al

Thanks, all.

It's obvious to me that my description of the grow-bucket I'm putting together didn't allow anyone to visualize the setup! This a version of an EarthBox but using two five-gallon buckets nested inside each other with a water chamber below the soil chamber.

The wick chamber is a cup (with holes in the side) that extends from the inner bucket down into the water chamber below in the outer bucket. If filled with soil, the soil is supposed to act as a wick for the soil sitting above it. I just want to be sure that the plants will be able to receive water since the soil chamber above the wick chamber is 14.5" deep -- and the only water the plants in the soil will get is supplied by the wick chamber -- it is not watered from the top.

Just so you know, strips of the inside of diapers don't remain strips if you remove the plastic. Test it out in water. They disintegrate within a few minutes into mashed-potato-like mushes of tiny pieces of gel (Pampers, anyhow) and the material it's encased in! This is probably okay for the part of the strip that remains in the soil, but I'd think you'd lose the "structure" of the part that is in the water in a very short while and it wouldn't work as a wick anymore.

Anyway, I'm still thinking on it. Maybe I'll have to use several different materials in various setups to see which ones will most reliably wick the water into the soil above the water chamber. I hadn't planned on using strips of anything as a wick material since a chamber is available to put wicking material in, and that material might include soil.

Al, thanks. I think a number of non-natural materials would work as wick material -- I have some very old polyester fabric I was going to make something from, and I think it would work fine as wick strips for some setups that are not built on the EarthBox principles. I read the other thread and appreciate it a lot!

I have been growing tomatoes in 18 gallon home made e-boxes for four seasons now. I have used Lambert's potting mix as well as Jungle Growth, and Expert. Ingredients are mostly peat moss with perlite, wetting agent, etc. All have provided excellent wicking performance. I make sure that I've tamped moist mix into the two 1 quart wicking chambers and then wet down the rest of the mix as I fill up. Finally, I top off the bottom water chamber. From time to time, I've checked under the plastic mulch cover and always found tomato-happy damp mix. Once plant growth takes off, I have to refill the bottom water reservior almost every other day. Garaj

Hey, tapla...

Rayon isn't man-made, or at least not really. It's extruded wood pulp, so I imagine it would rot just as well as other natural fibers.

Linda

garaj

Thanks for the information. That's good to know. The wicking chamber for this 5 gallon double bucket holds about a quart of material with about a gallon of water surrounding it.

I fully expect to have to water it daily when it gets hot and the plants are really growing. I've a great spot for several of these containers not far from our back faucet.

Hey Leira - No, but the chamois is (man-made chamois) as opposed to goatskin. Good info, though. ;o)

Anney - It sounds like you needn't worry about additional wicking with the way you're set up.

Al

of the pot. You want something inert or you are going to get fungus. The part that will be submerged, fill with sand, then for a few inches up. That area will end up not getting any oxygen and nasty stuff develops that way and can spread...that's not very scientific but it has proven correct in my case.

Hi, drasaid

The double bucket has a horizontal aeration tube that supplies oxygen to the lower part of the soil and plant roots, so fungus, compaction, root-rot, and those nasties shouldn't be a problem. There will be quite a flow of oxygen available to the plants and soil, certainly more than a container that has only bottom watering.

Anyway, I appreciate the comments and am not going to worry about the wick medium any more. It's my first try at a self-watering, self-aerating, self-feeding container that I've constructed myself, so I'm a bit nervous about its working as it should!

I found some 1/4" braided polypropylene tent peg cord at Walmart ($1.48/ 50ft.) that wicked to a height of 9" above the surface of the water. Does anyone have a wick that can pull water higher? I think this may be a limiting factor for the SWC design I am contemplating, thanks

It only has to wick water high/far enough to contact the soil, the soil, which also has strong capillary pull, does the rest. Think of a wick as a bridge between the water source and the soil.

Al

Al

Thanks for the "think of a wick as a bridge..." I need the visualization aspect to clarify this whole business of wicking, given that I'm planning to grow most of my garden in containers of various sorts this year. A couple will be wicked, about six will be grown in self-watering aerated containers, and some will be grown in large containers that will need to be watered often because they have no water reservoirs OR wicks. So I'm trying to get all the principles of water and aeration under my belt!

Your expertise is much appreciated!

I am testing a synthetic chamois. It wicks up water great at short distances. Guess we will see how it works in a couple of weeks. it is very promising and hopefully wont rot.

I'm making large self watering containers out of used boats, so I need a durable wicking material that comes in large sheets or rolls... Any suggestions?

so far i have cotton towel, felt .old t shirt cut up. cotton pillow case. sponge, but what sounds the best but not tried.is braided polypropylene tent peg cord at walmart.1,48 for 50 ft. only need about 16 ft, what we really need is some body to test them out, to see which works the best

In a container on a patio, elevated with planter feet, would it make a difference either having the wick dangle and drip versus touching the ground and acting as a bridge? Specifically regarding the competing forces to avoid perched water, it seems one might be better. I find the dangle and drip to be more satisfying, but for no reason I can articulate.

Prasad recommended coir/ coco peat/ coco pith (all the same) as a wicking agent, but roots will grow through the drain holes into the coir and coir is different chemically and physically from peat. It has a much higher pH than peat - which precludes use of dolomite as a liming agent, and less loft - which is why it compacts so readily when top watered and why it has so much less aeration when wet. It is very high in potassium, very low in sulfur and, often excessively high in manganese - which can limit uptake of iron, potentially very high o/a in dissolved solids (residual salt from being processed in sea water), and studies have also shown the significant presence of phenolic allelochemicals in fresh coir can be very problematic for a high % of plants, causing poor growth and reduced yields. My personal experience using coir as a direct substitute for peat have been very disappointing.

Chamae (short for chamaecyparis?) said: In a container on a patio, elevated with planter feet, would it make a difference either having the wick dangle and drip versus touching the ground and acting as a bridge? Specifically regarding the competing forces to avoid perched water, it seems one might be better. I find the dangle and drip to be more satisfying, but for no reason I can articulate. You might feel that way because it's more satisfying to actually be able to see the concept at work as water drips off the end of a dangling wick, but having the wick in direct contact with soil beneath the pot has greater potential when it comes to effectiveness.

What pushes water off the end of a dangling wick is gravity's effect on the water column in the pot - it's gravitational flow potential. Once a drop of water falls off the end of the wick, the force of cohesion to the remaining water on the wick is nil; whereas, if the wick is in contact with soil having the ability to absorb water (the pot is not sitting on a cement slab or in a puddle), the added 'pull' of water molecules to water molecules and soil particles increases the gravitational flow potential of the water in the pot by exactly the force exerted by the additional capillarity (which we know is the sum of adhesion + cohesion).

Al

Thank you Al.

I do like chamaecyparis so my name is a play on that, i.e. false gardener. It was either that or NewbieGardener

Does it make a difference to your answer if the pot is sitting on a brick patio, and wick is touching the brick?

Steve

If the wick is in a puddle, it diminishes the flow potential (FP) of the water in the pot, if the water can be absorbed into the filler between the bricks, the FP would be roughly the same as it would be if the pot was resting on bare earth; however, the rate at which the pot drained would potentially be slowed toward the end of the drainage process by the rate of percolation of water through the material between the bricks. There are so many variables that will affect the process, it's difficult to be perfectly specific about rates and effectiveness of various arrangements.

Al

Thank you. I have bigger problems that brought me to these forums anyways. You should be glad to know your gritty mix is the reason I am here.

I rushed into container gardening this summer and started killing a beautiful Chamaecyparis Lawsonia `Wissel's Saguaro' I received a month ago when I repotted it into potting mix from the garden center. I then found this discussion which has been ongoing since 2005 about water movement through a container and the benefits of your gritty mix.

I ordered the turface and pine bark fines from an Etsy seller, and a 50lb bag of cherry stone #2 grit from Amazon. About four days ago I mixed my first Als gritty mix and repotted it once again. It is pretty brown though, having lost its beaitiful blue-green color. Parts are turning brittle and flaking off.

This is from today. So if it decides to give up on me after I tortured its roots with such wet soil, I would not hold it against the gritty mix..

I'm glad you're here, but sorry to say needled evergreens remain green long after they have lost viability, so that tree was gone long before it was repotted. Save the grow medium for the next one, though. Maybe wait until spring to buy another and repot it about the time deciduous trees are leafing out. That will be least stressful. Repotting out of season can be a very traumatic event for a tree, not that it mattered in this case.

Al

What is the best potting medium for a self-watering container? I have a rather large planter (32'x32'x32') so half the bottom is the water resevoir. I read on another blog that the best wicking material was the nylon wrapped rope, the kind with a center strand that acts as a sponge. I intend to run the wick to the bottom of the resevoir and at least half way if not all the way up to the top of the grow bag, which will be my container for the plants. In this case a Tanyosho pine. Lots of moving parts...but if anyone is savyy on this, I'd like to know the best sort of growing medium. Right now I have Organic Mechanic, a very well draining loose soil mix, and a barky mix that has sand and appears to be more water retentive. Would love to hear feedback on this...as like a previous poster said, once this is in place, aint no taking it apart to fix...at least not one person.