Date: Fri 06-Sep-1996

Publication: Bee

Author: DONNAM

Illustration: C

Location: A12

Quick Words:

Suburban-Gardener-lawn-weeds

Full Text:

(`Burban Gardener on lawn care/maintenance, 9/6/96)

Suburban Gardener-

Reseeding Lawns...

By Anthony C. Bleach

It is a waste of your time and money to reseed areas of your lawn unless you

reduce the number of weeds. It may be unreasonable to expect to eliminate all

of them, but you should reduce their power either to root deeper or spread

seed.

Dicot weeds like dandelions and plantains can be spot treated with a can or if

in drifts can be controlled inexpensively using a hose-end sprayer. Current

research shows the hormone type weed killer is unlikely to reach the

groundwater.

Monocots like crabgrass can be selectively sprayed in mixed stands by products

such as Ortho Crabgrass Killer. But do not use a hose-end applicator. In pure

stands K leenup will kill all vegetation in a spot in a two-week period. In a

month the patch will be partly decomposed.

You can also do a lot of damage by twisting out individual crabs by hand and

trying to leave as much of your valuable top soil behind. The point is not so

much to eradicate as to suspend seed dispersal to that magic morning when

crabgrass has been melted away for another year by the first frost in October.

The best time to sow a lawn is from the middle of August to the middle of

September. The bluegrass and fescues we use evolved from the pasture grasses

of cool dewy meadows in England and only in the fall here are the conditions

similar enough to risk the investment of your time and money.

If it is a new lawn, a soil test by the University of Connecticut is a wise

move. Most land in the state is acid and the computer printout will tell you

exactly how much lime you will need as well as phosphate and potash. Kits can

be obtained from your Agriculture Extension Service. Call the Torrington

Office at 626-6240.

The success of establishment depends upon how well you prepare the seed bed.

Make sure the soil is loose enough to allow the grass to root six to eight

inches deep.

Aim for a surface of grape and walnut-sized soil crumbs. Dust will cake into a

seedling - impermeable crust when it rains. If no soil test has been done,

spread fifty pounds of limestone and twenty pounds of 5-10-5 fertilizer per

1,000 square feet.

Do not seed if the bed is puffy. It will dry out and kill the seedlings. Rain

and sprinkling will settle the soil if you have this problem.

Buy a seed mixture whose components will adjust to the different soil and

disease conditions of your yard. You can choose "play," "shade" or premium

mixtures.

The "premium" will contain a high proportion of the "shade" fescues and the

"play" ryegrass and bluegrass. There should be two or three named varieties of

each. For example, here are the ingredients of Scott's "Play" mixture: Thirty

percent Ovation perennial ryegrass, thirty percent Manhattan perennial

ryegrass, fifteen percent Victa Kentucky bluegrass, fifteen percent Derby

Kentucky bluegrass and ten percent Nassau Kentucky bluegrass.

Sow at about two ounces per square yard. If you bought seed at sale prices at

the end of last season, increase this a bit to allow for the decrease in

germination percentage with age. It is hard to get an even spread of seed

unless you do this:

1. Divide the seed packet into half for each 1,000 square feet. (The packs are

usually sold for this area. If not, you will have to weigh it. It will be

about 14 ounces.)

2. Mix each half with one-quarter to one-half pail of sand or fine soil.

3. Spread this mixture evenly, walking one way with the spreader and the next

time at right angles to make a grid pattern.

4. Repeat every 1,000 square feet.

5. The books tell us to rake the area over slightly so the seed is covered no

deeper than one-quarter of an inch, but I always drag the seed together so

when it germinates there are bare areas that have to be patched up. So I leave

it bare and compensate for the shallow seed bed by seeding at twice the rate

and adding fertilizer for quick establishment.

You can wait for rain for small areas, but a large area will germinate

irregularly unless you keep the top half-inch continuously wet with a

sprinkler. You will have to watch carefully to make sure all the seeds have

germinated.

Perennial ryegrass will show first but the bluegrass will not for another 7 to

14 days. So don't stop at the first blush of green or the bluegrass will die

from neglect.

Mulching is worth it. Many garden soils are not very permeable and you often

get soil washouts, particularly on slopes. You are also plagued with puddles

which expand so quickly that you have to turn off the sprinkler until it soaks

in.

A layer of hay or straw on the top will ensure a more even and continuous

moisture level. Spread it thin enough to see the soil surfaces. You don't want

to smother the grass. Estimate 1-1« bales per 1,000 square feet.

You will usually get an infestation of weeds from hay or straw, which can

easily be controlled with 2-4-D weed killer. Theoretically, salt hay is the

best material for mulching. This is made from grass grown near the shore where

weed seed will not germinate. But even if it is available it is very

expensive.

Dull blades will always rip up seedlings. Cut first when the grass is over

three inches. Do not cut shorter than two inches, as the leaves are vital for

the young turf's food supply.

It is a good idea not to cut off more than one third of the grass height.

Cutting grass lower always shocks it and it will just stop growing for two

weeks until it recovers. It is very good management to let grass grown in

shade reach four inches before giving it a high cut. Shaded grass needs more

leaf areas to make its food as its light supply is so limited.

Unless we are able to water our lawns through the summer - and it seems a

crime to waste drinking water for this - we will have patches in our lawns

which succumb to drought, fungus or a combination of both.

Overseeding is a technique we can use as routine management. Rake out the dead

stuff and rough up the soil to make a seed bed with a metal rake or, even

better, a thatching rake which has tines like knives.

For a large area you may want to consider renting a de-thatching machine. This

cuts narrow grooves into the soil which makes a good seedbed. But an

uninstructed user can cause a lot of lawn damage in a very short time. Choose

a rental center that can advise you on operation and adjustment or if you can,

hire an experienced professional.

(Anthony C. Bleach coordinates the horticulture program at Naugatuck Valley

Community Technical College in Waterbury.)