Suddenly I'm noticing signs of death-by-drought appearing all over my neighborhood. Not just wilting, but some dead stems, too. And I notice that some newly planted perennials have already turned crispy brown. Yep, heat and drought are here now, and attention must be paid to all but the most drought-tolerant plants. So let's tackle the suprisingly tricky issue of watering - the source of more Plant Death by Homeowner than any other cause.
How to Water
Deeply, but infrequently. For example, a new azalea needs two or three gallons of water directly to its roots after planting. Shallow watering does more harm than good, causing roots to grow close to the surface. Use the "drench" setting on your hose nozzle, 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.
Plants that were bought or moved in the spring or summer need serious coddling until winter just to keep from them dying in the heat and drought. This may seem counter-intuitive, but it's not the cold that kills plants. Except in the coldest of climates, it's more often the heat, sun and wind that kill garden plants. Other plants that need frequent watering are vegetables, plants in containers, and most annuals. 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.
- 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.
- Much cheaper are soaker hoses, considered the best choice in watering systems and with timers attached, they're a low-maintenance solution that uses waste efficiently. 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.
- Overhead sprinklers are wasteful (though the impulse type is less so) and require lots of fussing to get good coverage in larger gardens, in my experience. And with all that fussing, some hand watering is still required to get behind plants that block the spray (unless you use a tripod sprinkler).
- 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.
Careful with New Plants!
- When plants are put in the ground in the late spring or any time during the summer, it's a huge challenge to keep them alive through that first season because their roots can't handle heat and drought yet. (In their second season you can relax about it, or if you plant in the fall.)
- How often to water them? Small plants like perennials need watering at planting, then again the next day, then 3 days later, then weekly throughout their first summer. Larger plants like trees need that first deep watering, then again in 3 days, then weekly for a month and twice a month for the remainder of their first season. These guidelines assume the lack of long rains, of course.)
- "Drought-tolerant" new plants still need to be coddled their first season.
- When planting shrubs and trees in the fall, be careful not to overwater — it's the most common cause of early demise at that time of the year. Their roots aren't developed yet, so just soak them thoroughly after planting, apply mulch, and don't water again for a week.
Did it REALLY rain?
One common mistake is assuming that because some rain fell from the sky, you don't have to worry about watering. Even five-minute thunderstorms give people the false assurances that they needn't water. Wrong! Especially after periods of drought, it takes long rains to penetrate to root zones, and if in doubt, poke a few inches down in the ground to check for water. Or try one of those stick-type water gauges.
- Save time and possibly your plants by grouping the ones that need frequent watering.
- For hand watering, hose guides can save plants from decapitation by garden hose.