Friday, July 2, 2010
Getting Dry... Good, Bad and Ugly
OK getting dry might be an understatement. It is DRY in Bucks County, PA. When I see roadside weeds wilting, it’s dry. And today’s newspaper says, “Hot and dry with no rain in sight”. I think that means no rain in the forecast. Sure enough, the 7 day forecast is bone dry.
Let’s start with the good aspects of dry. My farm friends (who have irrigation) tell me that they will take a dry year over a wet one anytime. It is possible to add water but impossible to take it away. Heat and sunshine combined with timely irrigation equals wonderful tomatoes, peaches and other produce. Sure they have the chore of moving pipes and running pumps but they have control of the water. Same thing goes for home gardens.
And that late blight problem we are watching… it's gonna have trouble getting cranked up in these conditions. Notice how the sycamores have leafed out again after the ravages of early season leaf diseases. Thank the dry heat.
The bad…I think most folks underestimate the damage water stress causes to plants. Especially woody plants. It’s pretty obvious when you neglect to water the petunias or tomatoes. They wilt and probably recover when watered; if not, they die and you move on. In any event, they are annuals so you get another chance at minimal expense. With woody plants, the effects of drought are often harder to see and the effects may take awhile to manifest themselves. Often times it is borers, or even disease, that finish off these drought stressed plants. It may take years.
Just for fun, I observe lots of new landscape plantings. New housing developments, commercial sites, even the grounds of our Extension office. Frequently (if not usually) the newly established trees and shrubs are subject to severe drought stress in the first 12 months of planting. When they can least tolerate it. It is good to recall that these plants arrive to the site with a severely diminished root system. A lot of it was left behind in the nursery when the plant was dug. Even containerized plants have an abnormally restricted root system. Believe it or not, sometimes the plants that are established on these job sites arrive already drought stressed. Dormant plants that don’t “ leaf out” normally are suspect in my eyes.
OK. What does this mean? Right now, trees and shrubs that were planted within the last 12 months need water. If you wait until leaves wilt and fall off you have waited too long. Anticipate the watering needs of these plants and give them a good soaking before they wilt. Check back in a week and repeat if necessary. A good soaking is hard to quantify. How about this… 5 – 10 gallons per tree, applied at the base of the plant, slowly so that it soaks into the ground. Repeat weekly as needed. This requires a hose and some time. A watering can won’t cut it. Mother Nature will eventually come to our aid but until them, make a date with your trees and shrubs weekly. That green thing shown above is a "gator"; an irrigator bag. A handy device that allows the bag to drip water into the soil at a nice, slow rate, but you can fill it quickly.
The ugly…of course, complete neglect in a drought results in dead plants. Maybe not dead now but drought stress can show up as “winter injury’, borer damage or even disease in the long run. Going on vacation? How about a good soaking before you head off. The trees, not you.
Finally, although it is hard to imagine in a drought, it is possible to have too much soil moisture. You can over water. Automatic irrigation systems (improperly manage) kill plants.
Wouldn't it be wonderful if it rained an inch a week, every week, preferably between midnight and dawn. There are places in the world where temperatures and rainfall regular and predictable, within the growing season. Pennsylvania isn't one of them.