I’m looking for time-saving irrigation methods will get water right to plants’ roots but won’t water weeds. What are the best garden watering systems for these goals?
In her 2015 article Choose the Best Garden Watering Systems, Barbara Pleasant described some of the most efficient watering systems for your garden, including soaker hoses, drip irrigation, and buried reservoirs. These not only grow healthier plants and save water but also minimize weed growth and reduce watering and weeding time. The secret? Feeding water and nutrients to the plants you want and starving out the weeds.
Ceramic-based irrigation systems, such as olla irrigation, buried clay pots, porous clay pipes, and porous capsules, are some of the best watering setups for small plots. Using these methods, you can put fertilizer and compost right where the crops will get them. Water moves through clay walls at a rate that is based on plants’ water demands, so weeds have little to grow on, and the dry, open soil between plants will support few weeds. In areas with little summer rain, the difference can be striking. In a recent study, weeds around plants grown with clay pot irrigation weighed 200 pounds per acre compared with 8.5 tons per acre with conventional surface irrigation. Think of the hours — even days! — saved hoeing and pulling weeds. A heavy mulch between plants will control weeds even further.
Just a couple of years ago, few of these porous clay pot systems were available. Now, there are many olla suppliers. You can also use standard porous terra cotta pots and plug the drainage holes with a rubber stopper, epoxy, or hot glue. Cover the top of the buried pot with a plate from a thrift store or a pot base. Drill a small hole in the lid to let rain in.
Wick irrigation, which relies on a fiber wick to transfer water to soil, is even more efficient than clay pot irrigation. As the plant uses water, it draws more from the reservoir through the nylon or polyester wick. Wicks have long been used for growing African violets because these flowers are so sensitive to water on their leaves, but wicks also work well for many other plants. When growing smaller plants, you may only need to refill the wick reservoir every week or two. Wick irrigation works well in hanging baskets and window boxes, and these setups are available commercially as Wickinators.
Deep pipe irrigation often works best for larger shrubs and trees. It uses an open vertical or near-vertical pipe to deliver water to the root zone, which leads to deep watering and excellent root growth while minimizing weed growth. The pipe can be plastic, metal, or bamboo with the nodes drilled or knocked out. A commercial model called Deep Drip is now available at most home supply centers.
You can achieve an efficient watering setup by intensively managing any irrigation system, such as drip, sprinklers, or even a watering can or hose, but olla irrigation, wick irrigation, and deep pipe irrigation will make it much easier. Few comparison studies have been done, but my own work shows that these methods resulted in four times more tomatoes.
These more efficient irrigation systems will also save you time watering because you’ll likely need to refill them only once a week. Compare this with watering once a day if you’re hand-watering when plants are young. These garden watering systems are ideal for busy gardeners who can’t get to their gardens until Saturday morning.
Try a comparison in your garden this year — you’ll save time, energy, and water, too.