A pic of your stock tanks would be helpful.

I have them up on cement blocks now, but here's a pic from last year.

What you're draining is water that had ponded in the bottom of the stock tank. I don't think you ever want to have ponds down there. So you want a valve you can shut off to allow those ponds to form? I don't understand. Properly moist soil won't drain through holes that you leave open. With one-inch holes (I gather that's about what you have because of the hose valve you've shown), I can't imagine you're going to get much drying of the bottom layer of soil.

In flower pots, one doesn't have a valve to close off the hole in the bottom. Why would you want to have a valve at the bottom of a stock tank?

The water seems to very quickly drain out, leaving it all too dry. I'm thinking that if the water does pond, it may, by capillary action reach up to some of the roots......that are too dry because all the water drained out. Is my thinking correct?

Like Dan says you never want a pond in the bottom unless, like with self-watering containers (Earthboxes and such) you have the soil separated from the pond except in the wicking corners. That only causes root rot.

If there was a way to turn this into a SWC with a perforated ledge part way up from the bottom and then the soil on it (pull up the Earthtainer building directions from over on the container gardening forum) then you would permanently plug all the bottom holes and drill one overflow hole 2-3" up from the bottom edge of the container. But to do that you would have to empty it out completely and start from scratch.

The other alternative is to improve the soil water-retention ability in the container with clay or some of the moisture retention additives.

But IMO having to water every 3-4 days on a container this size would seem about normal - depending on the weather. No container is ever going to be like an inground bed when it comes to watering.

The plastic shut-off valves pictured above might work for awhile but I can't see them as a long term fix as they break down from heat in the course of a summer.

Dave

You will have to drill new holes to use those valves but also find a way to seal the large holes. Landscape fabric applied with some epoxy may slow it down enuff.

While the sun is hard on many plastic materials no doubt. As for the sun damage to the valves - I expect if these are on the bottom they will not be exposed to the sun like the plastic tank will be - so they should last longer than the tank.

Thanks all. I won't be drilling any new holes. I think there are things out there that would fit a 1" hole. But......just remember I drilled about 8-10 1" holes in each tank. I think what I might do is in the early spring next year, just cover up a couple of the holes. And yes, I do need to amend my compost soil with plain dirt. That will help keep the water in longer. And I need to put lots more of all soil/compost into each tank, as some of the stuff I put in this spring has sunk to only about 6-8".......which isn't enough to hold much water. Fortunately everything in the stock tanks is doing fairly well, considering the monsoons we've had up until now, and how bad the "in-ground" garden looks. As bi-polar as the weather seems to be getting, we'll probably go into a drought now. I haven't had to water my garden once, (just a couple of the stock tanks). I have to admit, I miss those morning waterings, spraying while sitting in my golf cart, enjoying the wildlife and the breezes.

If the surface remains nicely moist because you have a lake underneath, you've got a problem. As Dave said, root rot is then pretty much assured. I'm not sure how you're judging that the bed is drying out. Sure, the surface is going to get dry, if you don't have that lake underneath. That would be completely normal. If the surface stays moist, things are probably too wet. I can't imagine that several inches down it's drying out, however. That's where you want the moisture.

catherinet said: Thanks all. I won't be drilling any new holes.

Perhaps new stock tanks are the way to go then. Or if you have something you can put under them to hold the water like you would put under a pot? A drain pan, prob is finding one large enuff.

If use a piece of threaded pipe (schedule 80 pvc or galvanized that fits the size hole you have then use the threaded nuts for electrical conduit (they are the same type thread as the pipe) and some washers and rubber washer you can make a water tight connection.

I would just use duct tape.

Thanks maplegarden......that's what I was thinking would work too.

Me thinks that for what you would pay for plumbing pipe you could buy new stock tanks but hey whatever works.

I call it COG - (Cost of Gardening) = how much are tomatoes worth?

These stock tanks are around $150/ea.

dats some pricey tomatoes (vegetables)

COG

Yeah, but they are food-grade. But mostly it's because I'm 65 with a lot of painful arthritis throughout my body and having them raised will allow me to continue gardening. I'm fortunate to be able to afford them, and they will keep my spirits up. I've been gardening for 40 years and I can't imagine not being able to.

I understand. Gardening continues my therapy.