Make a continuous watering system work for you

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Making your own rain barrel can help you cut costs in your garden while increasing both the quantity and the quality of your produce.

Greg, over at NashVeggie, has put together a pretty nice pictorial of how to make your own rain barrel on the cheap. I’ve seen other barrels similar to his, and I’ve given considerable thought to building something a little more ambitious in my own “space challenged” garden*, so allow me to add my thoughts to his.

A problem to solve:

I’ve found that I get a dramatic boost in output IF (and only if) I never, ever, let the soil dry out. “Mid-day wilt” might be a natural response, but it is NOT the optimal response. And standing around with a watering can in my hands simply isn’t on the agenda. Not today. Not ever.

A simple water barrel, unless it is mounted way high, offers too little water pressure to power anything more automatic than a bucket. It’s not likely that I am going to use that arrangement very often. Certainly not often enough to keep the soil continuously moist. The word ‘continuously’ is the important one here. Even a few hours of wilt is damaging.

Nay-sayers Anonymous:

I can hear the nay-sayers with their nay-saying now. They are saying that allowing the soil to dry out between waterings forces deep rooting and that deep rooting is, as Martha would say, “a good thing”.

Forced deep rooting is accomplished by killing the shallow roots that the plant already had. Killing roots that the plant has already invested energy into growing doesn’t make a lot of sense to me. I’ve found that keeping the soil continuously moist allows the deeper roots to develop, too, without the loss of the shallower roots. If the plant needs deeper roots to cope with the heat (transpiration loss), it will develop them. But stressing a tomato plant, for instance, with drought will lead to low output and blackspot (a calcium deficiency that looks hideous) on the blossom end, rendering some of the fruit that does develop unusable. It will also render every plant in your garden more vulnerable to insects and disease. Any stress will accomplish that last part and drought is as good of a candidate stress as any.

It is fine with me if, as a result of keeping the top of the soil most, the roots don’t probe more than a few inches. This is because the bulk of the bacterial action that produces the needed nutrients is in the first few inches of soil anyways. This leads to a problem, though, in that the water I apply continues to travel downward and these first few inches of soil are also the first to dry out. A weep or emitter irrigation system can keep that top layer of soil as moist – and biologically active – as the floor of the Amazon forest. I recommend the weep style of system because it is dependably reliable, very reasonably priced and very simple to install and operate. Once installed, it is an entirely passive system.

I’ve grown 14′ tall tomatoes in Michigan using this method with well over a bushel of fruit from each plant by this method. It works. Four years later, I’ve still got plenty in my pantry.

Moreover, it does not require that I be rigid in my plant spacing and layout. This is a good thing for those of us who use interplanting or rotation planting as part of our gardening techniques because, at various times in the season, the same general area may be occupied by several different plants planted in slightly different locations. With the Tyvek weep lines, I simply turn the water off for a few minutes, pull the lines from their old locations, dig a shallow trench in the new location with the corner of a hoe or the point of a triangular planting / weeding hoe, drop the lines in the trench and re-cover them.

Done. But that’s okay: that wasn’t the fun part of gardening anyway.

For each answer, a fresh question:

As you work in your garden, you are using sharp tools around delicate lines. You WILL cut them. Although the emitter lines are harder to accidentally cut into, they are also more expensive to repair. To repair the weep lines, simply clamp the supply end off with a paper clip and let the line dry while you go to a fast food restaurant to get a plastic straw. Don’t steal … pay for a small drink. For the sake of your health, make it water. Save the straw. On your return, snip off an inch or so of the straw and use masking tape to attach the cut ends near the middle of the straw. Keep track of the rest of the straw because 1) it doesn’t need to be in a landfill just yet, 2) you don’t need to be in a fast food restaurant, either and 3) summer isn’t over.

After finding a source for a suitable used barrel, which is, in my experience, the toughest part of this project, Greg says that less than $25 in parts from any decent hardware store will finish the job. My own estimate is that the out-of-pocket cost is quite likely to be under $10, as almost anyone reading this page will have some or all of the pieces already laying around, unused. For instance, he bought a ‘no kink’ hose bib. That’s fine, and it obviously works, but either raising the barrel or turning the bib sideways when mounting it will also avoid kinking the hose and, even if you have to buy ‘new’, the regular hose bibs are only about $3-4.00 in Detroit. You’ll notice that Greg is going to have you raise the barrel after all … so why not buy the cheapest valve you can find with the right threads? You may even have a hose bib sitting around in your ‘junk box’ of plumbing parts. Over time, most of us develop a box or two like this … stuff that still works, pulled in the process of fixing something else that really was broke. Too good to toss – but with no immediate use – they collect in boxes patiently awaiting a moment of inspiration or even of desperation. I could probably get everything else he mentions for around $5 new. With the exception of the O rings, however, they don’t need to be new and there are ways other than using an O ring to seal the hole. In fact, the other methods, such as applying a liberal shot of silicone adhesive, might actually be preferable, since the washers he uses will not have a retention groove machined in them to capture the O rings. Just wet an old rag (or fingertip!) with water and wipe away any excess adhesive after the parts are tightened and you’ll end up with a very neat job.

This is, after all, ‘just a water barrel’ and probably not the centerpiece of your home or garden.

Your mileage may vary, but small deviations from his design are probably worth giving some thought to. He used, for instance, a PVC pipe fitting on the inside of the barrel. From a corrosion standpoint, this might make some sense, but, since the plastic barrel is going to degrade in the UV light found outdoors, I honestly don’t see the barrel lasting long enough for the corrosion resistance to matter. Use, if you wish, a pipe fitting made of iron pipe. Iron helps keep your plants green and iron from plants helps keep you healthy, so a little regular corrosion would actually be to your benefit.

You can ‘customize’ his idea by adding a drip or weep irrigation system powered by the tank. (That’s not an affiliate link … I just like the product.) If you do this, make certain to raise the tank several feet to insure that gravity will supply enough pressure to keep the lines pressurized. The top of the water needs to be at least 7′ above the surface of the garden in order to give at least 3 psi at the soil level. A 2×4 or 4×4 stand should prove more than adequate if you have at least rudimentary carpentry and design skills. Keep in mind that a gallon of water weighs about 8 pounds. Thus, 50 gallons is going to weigh about 400 pounds. For this reason, make the support sturdy with a firm foundation. If the soil beneath it is on the sandy side, you might want to spread the weight around by putting it on a stone bed or some sort of concrete / concrete block foundation.

Think about it:

With a little thought (and either a toilet or stock tank fill valve & float) you should be able to keep some water in the tank at all times but allow the rain water to improve matters. Tap a garden hose into the toilet float valve and place the float valve near the bottom of the tank in a manner similar to how Greg illustrates for sealing his hose bib. As discussed below, the actual height might be a bit fiddly.

The float valve will keep ‘some’ water in the tank at all times (enough to power the irrigation system) but the rain water will fill all the space above the float with chlorine-free / nutrient rich water. Keep in mind that the level of the “some” water will need to be 7ft. higher than the garden soil. Adjust the float so that the valve opens at this level and all will be fine. This is the ‘fiddly’ part, made somewhat more challenging by the fact that most of us live in single-story homes and our gutters are not much more than 7′ above the ground.

If you live where winters result in freezing temperatures, don’t forget to completely drain the whole system in the fall and to divert the water from the downspout away from the water tank until the weather is reliably warm next spring.

If you buried the weep tape (shielding it from UV rays while reducing evaporation loss) you can also store it, loosely coiled, indoors and get a second year from it. Don’t plan on re-using it if you left it outdoors all winter or if you didn’t shield it during its first summer.

The nicest thing about a watering arrangement such as this is that you can walk away from the garden for a vacation trip and know that the garden will not only survive, but flourish. If you are also a mulching ninja, even the weeds will still be under control when you return.

*I can’t actually implement those thoughts until I’ve had a chance to dig up the drain line from my house that runs under my garden — but is plugged by tree roots from the neighbors elm tree.