The Memorial Day weekend is a non-working time for most homeowners, albeit some routine chores will need tackling in the cool hours of the morning, after which you can pick and choose garden tasks as you wish. Some parts of the landscape should be left untouched until next week as part of the transition from spring to summer gardening.
For those who prefer to make this a constructive weekend, it's time to bone up on lawn management practices as May gives way to June.
First, the news everyone wants to hear. If you've been cutting the lawn "short" through the spring, skip cutting it this weekend because you want to raise the cutting height.
When you next cut the lawn, the wheels of the rotary mower will be adjusted accordingly. At that time, move to the highest cutting height (three inches) for fine fescue and tall fescue. Perennial ryegrass should be cut at 2 1/2 inches (one rung lower than the highest wheel setting) and Kentucky bluegrass at two inches (two rungs lower). Zoysia should be cut year-round at one inch, the lowest wheel setting on the rotary mower; if you have been cutting zoysia high this spring, bring the cut down in weekly stages so you don't remove excessive leaf blade at any one cutting.
If you have been cutting your lawn at these heights through the spring, don't skip mowing this weekend. You've been cutting at the "summer height" and you want to maintain this through the summer.
Second, your lawn is already going dormant for the summer. If you have been bagging your clippings, you've already noticed a drop in the number of bags produced at your existing cutting height. Even with the increase in cutting height next week, you will see a further reduction in the bagged clippings from the lawn. Turf grass growth will be minuscule, only resuming in late August or Labor Day with the first application of fall fertilizer.
From here on, assuming your sunny lawn has no weeds, leave grass clippings behind. Since clippings are 95 percent water, they will decay to humus in a little more than two weeks, enriching the soil in the process. If weeds dot the lawn, bag your lawn clippings through the summer.
If blackbirds and sparrows have been pecking away at the sunny grass over the past week, it means you have a good population of adult chinch bugs and sod webworms at soil level, meaning that you didn't apply Oftanol to the lawn in early April. Had you applied Oftanol then, there would be no chinch bugs or sod webworms on the lawn to attract the birds. Up to now, these soil insects have not inflicted any damage to the lawn, but that will change shortly as the June mating season begins. It will be mid- to late July before insect damage is noted on the sunny lawn.
Early next week, adult Japanese beetles will be flying out of sunny lawns to begin feeding before mating commences the last week of June and the first days of July. Beetles will fly first to bedding plants, defoliating some in the process before heading for the rose garden. By mid-June, beetles will own the rose garden.
If you have beetle traps from last year, buy new bait at the garden shop and erect the traps the weekend of June 23-24, at which time the trap will start attracting male beetles. If you didn't use traps last year, wait until you encounter beetles in your garden in the next few weeks, then buy traps. The bait, a pheromone, releases a scent comparable to that emitted by the female preparatory to mating. Male beetles are trapped, thereby reducing the beetle offspring as females pass the summer without mating.
Looking ahead, don't expect to have any lawn problems from the beetles until well into July. Eggs deposited on sunny lawns normally take 10 days to hatch, therefore it won't be until July 10-15 before Japanese beetle grubs start feeding on the roots of sunny grass. Damage will be spotty in late July, but grub populations in the soil will reach staggering numbers come the first week of August.
Over the last weekend of July, you will apply granular Dylox to the lawn, soaked in, to destroy present and future grubs. If you elect not to treat the sunny lawn in late July, you face the blood, sweat and tears of total lawn renovation in late August.
For readers who are following our lawn program, stock up on granular Balan over the coming week. Balan will go down on sunny lawns next weekend to stop all goose grass from sprouting in mid-July, also to continue total crabgrass control for the rest of the year. Balan will also be needed on sunny lawns treated with Tupersan back in April.
By next weekend, the first major weed problems will be surfacing on sunny lawns: crabgrass and yellow nutsedge. If you treated the lawn with a preemergent crabgrass control back in April, you shouldn't see even one blade of crabgrass, but the same isn't true for nutsedge.
Nutsedge is easily identified. Look for a pale green "look alike" grass sprouting on sunny lawns next week. Since it grows faster than grass, nutsedge stands out; it looks like a pale green cornstalk, which it seems to be in its early stages of growth. Don't be shocked to find nutsedge sprouting where it never appeared before.
Nutsedge should be controlled soon after sprouting. In the one- and two-leaf stage, the weed is easily controlled with Rockland's Super Crabgrass Killer. (Tidewater, Richmond, Charlottesville and Shenandoah Valley gardeners should check their garden shops for Drexel's DSMA, which is identical in performance and concentration to the Rockland product.) Regardless, delay your application until our June 16 column lays out the basics. Lawns inundated with crabgrass will also be treated with the same product at that time.
Memorial Day also should signal a change in your watering practices, whether you do it by hand, with a lawn sprinkler or with an underground sprinkling system. With all lawns entering the summer stress season, the emphasis is on avoiding anything that would create or predispose the turf grass to disease. Since environmental conditions are starting to change dramatically, continuing your spring lawn management practices will quickly create problems.
For example, leaf-spot disease problems are basically over for the spring -- no new outbreaks are likely until the last week of September and the first days of October. However, brown patch weather is here, so poorly managed lawns (excessively fertilized and watered) could well see expanding circles of dying turf grass over the next few weeks. To play it safe, don't fertilize now.
On lawns irrigated like the Panama Canal, you are on the doorstep of pythium weather (temperatures 75 to 90 and high humidity). This is no time to be playing games with the lawn because one mistake could either destroy much of the lawn or cause you to skip a mortgage payment to buy the fungicide to control the disease.
If your lawn is on a slope of any kind, you should be aware than it is in danger as far as watering is concerned for the next four weeks. If the soil on the high slope is waterlogged, water will move to low ground and transport pythium spores wherever it flows. Pythium appears as dying or dead circles of grass, always with gray-white strands of disease that resemble cobwebs on blades of grass in the early morning hours. It is for this reason that pythium is often referred to as "cottony blight."
Managing your lawn carefully through the summer will rule out chances of any disease outbreaks.
First, water only to make up for shortages in rainfall, with the goal being to supply an inch of water per week to the lawn. Check The Post weather summary daily to determine weekly rainfall, then water accordingly.
If you have an automatic lawn sprinkling system, reprogram the controller so each sprinkler operates for five minutes after 5 a.m. to wash the dew (actually acidic guttation) off the blades of grass; by diluting this guttation, which is pressure-driven out the upper stomata of the leaf blade, you will reduce disease outbreaks on the summer lawn. However, the sprinkling system will go on full cycle one day during the week to provide needed water for the lawn.
Second, since your lawn (sunny and shady) is heading into the summer stress season, adjust your watering timetable now. Either water before 10 a.m. or don't water at all. Forget afternoon and evening sprinkling from now through Labor Day. If it rains, that's fine, but don't haul out the hose and water-sprinkle unless you do it before 10 a.m.
This is especially critical with shady lawns where the combination of nighttime temperature and humidity totaling 150 or more between 9 p.m. and 5 a.m. usually causes powdery mildew disease. As long as shady grass (and sunny grass, for that matter) goes into nightfall dry, powdery mildew won't strike.
NEXT WEEK: Spider mite season will have arrived, likewise lace bugs on azalea, pieris japonica and rhododendron. Check your supply shelf for Cygon, Kelthane and Orthene. Houseplants will be moved outdoors. There's still time to create a flowering oasis where the garden eyesore exists today. Jack Eden is the host of "Over the Garden Fence" Sundays from 10 a.m. to 1 p.m. on WTOP Radio (1500 AM).