Late Spring!
Look to the root cause of lawn's failure before
starting over
Dear Janet,
What do I do with lawn that pretty much died and
disappeared over winter? I dug around but didn't find many grubs.
There is a hard layer of soil under the sod -- my shovel goes in
easily for about two inches then stops dead.
Most of the grass is dead and peels up like rotten brown
carpet, but there are tufts of live green. I can't help noticing
how regularly spaced the green is, and wonder if the aerating I did
last fall is somehow related.
G.B.
Dear G.B.,
You're not alone. A great deal of grass needs replacing this
year
I'm glad you checked for grubs before buying grub killer.
Although my mail is currently full of questions about grub
treatments, what I've seen in my work and travels around the area
indicates that, in general, grubs are not to blame. It's
disheartening to consider so many people applying insecticide
unnecessarily, but worse to think that most are missing the
underlying problem and thus wasting their efforts.
The "hard pan" soil you describe is common under grass. It's a
consequence of home construction rarely addressed by those who lay
sod or spread seed around a new home. A major error, since hard pan
will not correct itself no matter how many years pass. Since water
and air can penetrate only about an inch, roots grow only that
deep. They don't reach even as far as your shovel did, because they
rot in the soggy layer right above the hard pan. In such a weak
state, a lawn can't survive the repeated droughts we've had. It
deteriorates and finally succumbs to diseases or exhaustion.
Live grass around the aerator holes are proof of this -- only
where the soil was deeper were plants able to survive. So before
you put down new sod or spread seed, do a more serious
aeration.
Rent the machine used to install irrigation pipe -- a lawn
tractor that draws a knife through the soil. Drive this back and
forth across the lawn, first one way and then at right angles, to
cross-hatch the whole area with slices spaced eighteen inches
apart.
Then spread a layer of compost or that mix of Michigan peat and
screened topsoil sold by landscape suppliers as "50-50 mix." Spread
as much as you can afford. One cubic yard of either material will
cover 300 square feet. Till this in, if the tiller's tines will
penetrate. Then rake the area smooth before sodding or seeding.
Short reports
Can I cut the roots of a maple that's ruining my
lawn?
Not a good idea. You risk serious harm to the tree and won't
even fix the lawn, which is being ruined by shade, not by
roots.
Is there hope for a rhododendron that lost its leaves if
the twigs are still green inside?
Where the wood under the bark is green and moist, there's hope,
if you can also support the shrub through a long recovery.
Can peanut shells be used as mulch or soil
amendment?
If it's available in quantity, you like the look and it will
eventually decompose, it's a worthwhile mulch. Peanut shells are
better for improving soil condition than shredded bark.
Look to your ash trees, Midlanders...
I saw a great deal of woodpecker damage on ash trees
there. That's not a sure sign but it is one of the symptoms
of ash borer infestation.
Look up. If you see piebald areas where woodpeckers picked away
at the bark, call in an arborist to go up, remove some bark in
those areas and check beneath it for the emerald ash borer's
distinctive serpentine galleries -- tracks left from the borer's
feeding.
Where you find this definitive sign of the borer, remove the
tree quickly before the borers begin to emerge and spread later
this month. Don't leave those trees or borers can build up in your
area to the huge numbers that were inadvertently allowed here,
before we knew what the problem was. If you could see Troy's native
wetlands, full of dead ash trees, or drive through some Livonia or
Canton neighborhoods that are now devoid of all street trees, you'd
understand the urgency to chip those trees into tiny pieces. Then
you may keep your other ashes for a while, buying time for
replacement plantings to grow.
Green thumbs up
to attentive watering of new plants. Let something new wilt even
once and its growth is reduced for the whole season. Use a seven
day watering system during the critical first weeks. Water on
planting day. Wait two days before watering again. Now let three
days pass, then four, and so on until there is a seven day interval
between one watering and the next.
Green thumbs down
to low expectations in flower planting. Why else would you crowd
annuals at 3 or 4 inches apart, even though the tag calls for 8
inch spacing, or more? Crowding insures poor growth, as each plant
will have that much less food, water and air. For strong, handsome
flowers, space plants as described on their tags, as is done at
botanical gardens.
Originally published 5/24/03