Best advice on watering: Water in the morning, water thoroughly, water less often.
As you will see when you read this article, nothing drives me crazier than seeing water being wasted. That’s why the development of a new drip-irrigation system gave me such pleasure – at last, an easy-to-use watering method that will help people conserve this precious resource. I hope you’ll consider giving it a try too!
Few things irritate me more than the sight of precious water pouring out of the tap and straight down the drain. A childhood spent in a small, drought prone Saskatchewan town taught me how precious water is. Gardens in particular consume plenty of water, especially during hot spells in July and August. Thankfully, reducing our consumptions is not difficult.
When people think of watering the flower or vegetable garden, they usually picture water wands, hoses, watering cans, sprinklers, or rain barrels. What doesn’t immediately come to mind is drip irrigation. Drip irrigation is a very efficient method of distributing water to plants – one drop at a time. This is not new technology, but it is almost unknown to home gardeners; it is much more common in large-scale operations. In our greenhouse, we use hundreds of metres of drip tubes to irrigate crops like hanging baskets and geraniums. In California, thousands of kilometres of drip-irrigation tubing are used to water strawberry fields.
Drip irrigation saves water because the pipes are laid on the ground in rows close to the plants’ root systems. The water has less opportunity to evaporate, since it is not being sprayed into the air and onto foliage, as is the case with overhead sprinklers. Not splashing water onto the foliage has one major side effect: the incidence of leaf diseases is greatly reduced. I remember ruining one string bean crop by aggressively irrigating it with overhead sprinklers. Almost overnight, all of the leaves were covered with bean blight, a rust-like disease properly referred to as Xanthomonas phaseoli. Sprinklers tend to splash mud laden with soil-borne diseases right onto the stems and leaves of plants. When the leaves are left dry and clean, fewer bacteria and fungi have the opportunity to become established.
With drip irrigation, patience is a virtue. Since the water is applied a drop at a time, irrigation in unspectacular and often seems interminable. But it does work, and well. As the water drips out of the emitters, it seeps into the soil vertically and horizontally. (Sandy soils have the least horizontal movement, while clay soils have the greatest.) Drip irrigation is best suited to plants that have been established for several weeks, rather than seedlings, since the root systems of many seedlings are too small to reach the moisture.
Drip irrigation systems are relatively inexpensive and easy to use. The pipe is surprisingly lightweight. I’ve picked up a 150-m roll of pipe and I’m sure it didn’t weigh any more than 5 kg. To illustrate just how simple this stuff is to use, imagine a vegetable garden with dimensions of 6 m by 6 m with 10 rows of vegetables. The drip is laid down along each row, so that there are 10 6-m lengths of tubing. At one end, all of the individual lengths of tubes are plugged or just folded and clamped. At the other end, they are all connected together. Barbed plastic connectors are simply pushed into the tubing. No tools or clamps are required, and even someone who is severely mechanically challenged (like me) will have no problem hooking the pipe together. Connect the system to your outside tap, and voila, you’re on your way to conserving hundreds of litres of water per year. One tip: before you begin, leave the coiled tube in the sun to heat up for a while to make it soft and pliable. Otherwise, it jumps around like an angry snake when you’re trying to install it. Drip tubing is especially convenient to lay down alongside rows of crops like carrots, onions, or corn, or even in beds of annuals and perennials, providing that it’s installed early, before the plants have become too dense to allow tubing to slide in between. Dependable and relatively inexpensive water timers can be attached between the water faucet and the drip tubing to set the frequency of irrigation: once a day, once a week, twice a day, or whatever you prefer. Duration can be set as well: two minutes, ten minutes, and so forth. If you know what the flow rate is in litres per minute and what the water requirements of the crop are, you can calculate exactly how long you should leave the tubes on to meet the plants’ needs. Removal in the fall is simple. Just pull it up, pull off the connectors, and store.
Of course, there will always be times when conventional watering will be more efficient than installing drip irrigation. If I use a hose to water, I always attach a water wand rather than one of those dreadful gun-like nozzles. Water wands deliver a focussed but gentle spray, and if you’re careful and hold the wand close to the plants, little water is wasted. And of course, sometimes low-tech solutions are still effective. Water collected in rain barrels and distributed with a trusty watering can is still one of the best ways to irrigate your plants while also being a conservationist.
For more information on drip irrigation systems, please visit us at Hole's Greenhouses