Summer is the real test for the Kentucky bluegrass-fescue lawn. No matter how well it thrives during cool weather, through the hot months protecting the turf from severe damage is about all that can be expected.
Once warm weather arrives, opportunities for improving the lawn are limited, and treatments should be carefully chosen and administered since carelessness may destroy the turf area already established.
The most productive efforts toward maintaining a good lawn can be made in the spring and fall.
Resolutions to fertilize and lime properly during those seasons are the best approach to summer enjoyment.
Natural Loss Of Color
It is natural for Kentucky bluegrass and other cool-season grasses to turn rather yellow or brown when temperatures are high.
Attempting to avoid this natural loss of color by fertilizing and watering throughout the summer may defeat the purpose by keeping the grass soft and more subject to disease and heat injury. It also encourages summer weeds such as crabgrass.
Regularly Watering The Grass
The healthy lawn will not be injured permanently by typical summer weather, and the average lawn maker should relax rather than try such practices as regular watering throughout the season.
While most lawns will revive after prolonged hot, dry periods, those in very sandy soils or warm exposures and ones closely clipped may be ruined unless judiciously watered.
Water should be applied slowly and uniformly until it moistens the soil as deep as it is dried out.
This amount should enable the grass to survive 7 to 10 days of additional heat and dry weather. Then, apply the water only as fast as it enters the soil.
A canvas hose or some other device to control the flow may be necessary for areas that absorb slowly.
The sod on compacted spots can be opened by cultivation with lawn forks of the spoon or hollow-tine type.
Where crabgrass is present, watering should be avoided as long as possible. Frequent and light waterings are undesirable since they do the permanent grasses little or no good yet encourage crabgrass to spread rapidly.
Controlling Crabgrass
Keeping the mower blade set 1 ½” inches or higher in hot weather prevents crabgrass runners from spreading and rooting so rapidly. Crabgrass cannot be cut close enough to stop it from front-setting seed.
Chemical preparations of phenyl mercury acetate and potassium cyanate are useful for crabgrass control if properly applied.
Instructions on the container for rate and frequency of application should be followed to avoid serious turf injury.
Trial applications on an inconspicuous corner of the lawn give the homeowner experience in the chemical treatment and determine whether the amount of injury is tolerable.
The Best Season to Apply Phenyl Mercury Acetate
The best season for applying phenyl mercury acetate preparations is from late July through mid-August; for potassium cyanate, the ideal time is usually somewhat later.
The phenyl mercury acetate preparations are quite selective for crabgrass and are available for spray or dry application.
While the dry forms may be easier to apply, they have given less consistent control. Potassium cyanate is better suited to the Kentucky bluegrass type of lawn than to the bentgrass type.
Usually, three to five applications of phenyl mercury acetate are required, while two or three applications of potassium cyanate may be required for control.
Improving Crabgrass Control
The use of chemicals for crabgrass control is not justified unless the permanent turf grasses are improved by regular fertilization and higher mowing.
For the Kentucky bluegrass-fescue lawn, the height of the cut may be kept at 2” inches until crabgrass is brought under control, then lowered to 1 ½” inches.
Crabgrass cannot be eliminated entirely in one year. Therefore, all plants should be kept from producing seeds for a period of several years.
Even then, it is better to keep the occasional plant from going to seed than to run the risk of a future infestation.
Chemicals Can Destroy Weeds
Dandelions, buckhorn, and broadleaved plantain are readily destroyed by 2,4-D preparations.
According to the instructions, a small quantity of this chemical can destroy a surprising number of weeds.
On the small lawn, a diluted solution of 2,4-D may be applied to each weed with a paintbrush if no sprayer is available.
This chemical, and the sprayer used for it, should be kept away from other valuable garden plants since it may damage them.
And if late summer or fall reseeding is planned, make the final treatment several weeks before.
Attacked By Diseases
Strange as it may seem, turf grasses are attacked by diseases, including brown patches, dollar spots, and copper spots.
The golf course superintendent controls them through careful management and fungicides.
Since good control with fungicides requires regular applications before the disease attack, it is troublesome for the average homeowner.
Proper liming, careful fertilization, and limited watering keep disease at a minimum.
According to instructions, the lawn hobbyist with a fine-turf lawn might use mercury or cadmium fungicides. Unfortunately, Bentgrass lawns are more susceptible than others to disease injury.
Japanese Beetle Grub
The Japanese beetle grub may do considerable damage in August and early September when the young grubs feed heavily on the grassroots.
A large infestation kills the grass by cutting the turf at about an inch of depth. The symptoms are spongy sod or turf that is easily lifted.
Once found, the grubs are controlled by applying 6 pounds of 10% DDT or 5 pounds of 5% chlordane dust per 1,000 square feet.
Spread the insecticide uniformly and water it in if possible. Such DDT treatments should last 7 or 8 years, while chlordane appears to lose its effectiveness more rapidly.
Young Chinch Bugs
Hot, dry weather is the time to watch out for chinch bugs. Unfortunately, it is difficult to spot them in time to prevent damage.
The young chinch bugs which feed on the grass may remain unnoticed until the injury is severe. By that time, they had become adults and stopped feeding.
At the first signs of any unexplained lawn discoloration in the summer, look for the young reddish chinch bug, which may be present in vast numbers.
Then apply 3 to 5 pounds of DDT or 5 pounds of 5 percent chlordane dust per 1,000 square feet wherever an infestation is found.
Using Maleic Hydrazide
These treatments last for one season only. Maleic hydrazide is a chemical sold as a growth retardant for lawn edges.
Tests have shown that when used over an entire lawn, it may check growth but also cause serious turf injury later in the season.
Also, weeds make more progress when the chemical prevents the grass from growing and competing.
Those who wish to experiment with maleic hydrazide should use it first on a trial basis in restricted areas. Then, fertilize the lawn in September and early spring for the best results.
Fertilization during the warm weather of late spring and summer may help keep the grass green, but it encourages weeds and sometimes leads to serious turf damage.
Summer Fertilizing
The experienced turf grower may recognize the occasional need for summer fertilizing, but he, too, must exercise great care in fertilizing at this time.
Shaded lawn areas or other problem spots may benefit from light fertilizer applications during summer.
However, beware of scorching the grass. For 1 000 square feet, 4 to 8 pounds of an 8-6-4, 5-10-5, or similar fertilizer might be spread and watered in without delay.
Organic nitrogen fertilizers such as activated sewerage sludge, castor pomace, and animal waste fertilizers may be applied at slightly higher rates without watering. Or small amounts of soluble fertilizer are sometimes applied as the lawn is watered.
High mowing benefits shaded lawns since it permits more grass leaf urea to remain for food production.
Mowing closer than 1 ½” inches may tax the grass plants so severely that they cannot survive the summer.
When grass nears the wilting stage, it is particularly susceptible to injury from heavy traffic.
Spreading the wear over the lawn helps avoid the loss of grass and increases the service life of the turf.
With the best care, summer will likely leave its disease, drought, or crabgrass stars on the lawn, where even greater future troubles may start.
Most lawns should be fertilized in late summer or early fall to encourage vigorous growth during the cool, moist weather that follows.
Recovery From Fertilizer
The amount of recovery a properly fertilized Kentucky bluegrass lawn can make in autumn is amazing.
In late summer also, reseed all bare areas or they are likely to revert to weeds next year. The right seed and correct fertilization are important.
For the cool moist areas of the country. Kentucky bluegrass, chewing or other red fescue and colonial bentgrass are the main kinds of grass seed.
Be sure the seed comes in contact with the soil even if this necessitates scarifying the bare spots and breaking through weeds and trashy litter at the surface.
Turf Cultivating Tools
Turf cultivating tools, purchased or rented, may be useful for this purpose. The cool fall months give new seedlings plenty of time to prepare for the rigors of next year’s hot weather.
Even their arching foliage is an asset. They can be landscaped or massed, and are breathtaking against an evergreen background.
But I like them best in borders used with daffodils and iris. Here on Staten Island, this combination gives four months’ succession of bloom.
The borders are much more interesting if curved rather than straight, and should not be more than 6’ feet deep, because then it’s hard to care for them.
Permanent Planting
The diagram below shows the proper distance apart to plant these three perennials for a border that will give an established look the year after planting.
This border can be left undisturbed for three years, provided the iris are thinned out the second and third years.
For a more permanent planting, of four or five years duration, the iris and daffodils are 3’ feet apart, and the hemerocallis about 6’ feet apart.
Plant the daffodils in triangles. Use three double-nose daffodils of the same variety, spacing the two bulbs in front 6” inches apart.
(Double-nose bulbs give three flowers a bulb the first year.)
Planting Late-Blooming Varieties
Choose early, medium, and late-blooming varieties so the bloom will continue for a long period.
Plant the iris in rings—three rhizomes of one variety to each ring with the base of all touching because the iris grows forward and spreads outward.
The hemerocallis preferably should not be a single plant but a double division. But, unfortunately, the better varieties are not sold this way.
However, daylilies (hemerocallis) increase rapidly, forming clumps quickly. A final word of color advice: although light, clear, clean colors are usually preferable in the garden, with hemerocallis, more dark shades can be used to advantage.
44659 by Ralph E. Engel