These last two days brought our first real summer temperatures of the season, and suddenly I'm noticing plants wilting everywhere. Especially newly planted ones, which need coddling their whole first summer. Seems that humans aren't the only ones that need acclimating to heat.
So, time to review proper watering technique, starting with some Don'ts.
- Don't use overhead sprinklers - they're wasteful - or even the "shower" option on your hose nozzle when watering trees, shrubs, and perennials. Sprinklers are best for shallow-rooted plants, like seeds and seedlings.
- Don't water deep-rooted plants to a shallow depth - no matter how often you water! Frequent and shallow watering results in shallow roots, which means more frequent watering is then necessary. It's like a drug addiction - start a bad habit and it becomes self-perpetuating.
- Don't water when it's sunny, if you can help it. Especially if you ARE using sprinklers, because so much of the water will evaporate.
- Water deeply, but infrequently. For example, a new azalea needs two or three gallons of water directly to its roots after planting, so use the "drench" setting on your hose nozzle to direct water to the root zone, or remove the nozzle and just point the hose end around the base of the plant. Soak the soil to a depth of 4 inches.
- How often? Depends on the plant, and how well established it is in your garden. So, anything planted this season will need frequent watering, as well as the plants that always need frequent watering - vegetables, plants in containers, and most annuals. Frequency could mean daily for those container annuals, or more reasonably, twice a week in a hot spell with no rain for the others. The rest of your plants, if you've chosen them for drought tolerance, require supplemental watering only during droughts. Oh, except for any plants you may have growing under the roof overhang where rain can't help them — they're easy to forget until they up and die on you.
- Soaker hoses with timers attached great because they're inexpensive, low-maintenance, and water-conserving. They only work well on flat surfaces and over short distances, though.
- For more money, drip irrigation systems seem to work well, assuming they're designed and installed correctly.
- Automatic systems, though expensive, may be great for people who travel, but can kill plants by overwatering them. And the very fact that they're automatic may cause users to simply stop going into the garden to observe what's going on with their plants.
- One technique that works well for trees is a slow drip from the end of a hose. And by slow I mean for a couple of hours, at least. (Some experts say a minimum of three.) If the water is running off, decrease the flow. If there's an incline, leave the hose uphill from the tree. No need to move the hose around; it'll penetrate the area if allowed to run long enough.
- Hand watering, while time-consuming, is the method of choice by die-hard gardeners like myself. (Washington Post writer Adrian Higgins says there's a "Zen-like quality to it," and I agree.) I avoid spray nozzles and simply use my thumb to adjust the spray for each plant. Watering wands are highly recommended, though, and I'll be trying one myself soon.
More Watering Tips
- The best way to know if the shower or thunderstorm your garden experienced produced enough water to really matter is by consulting a rain gauge. Rain gauges are inexpensive and pay for themselves in saved plants and reduced water bills - as long as the gauge is actually consulted.
- Another water to save time and water is by grouping plants according to how thirsty they are.
- For hand watering, hose guides can save plants from decapitation by garden hose.