A Lawn Care Refresher
by Janice Hand
under the snow lies a lawn, which will turn green again in the spring, whenever
that may arrive. Looking ahead to the happy event, it’s time to check lawn care
practices. I just learned (and re-learned) a few things that others may find
- Dormancy is natural. Our turf grasses in northern Illinois are “cool season” grasses. This type grows during the
cooler months — spring and early summer and then again in fall. It is normal
for this form of grass to go dormant in the heat of mid-summer, and watering it
to keep it green can actually harm this type of grass. This form of grasses can
be weakened by on again-off again watering during its “off” (dormant) season.
Bottom line: do not water your turf during its natural dormancy period (unless
there is a very severe drought, and then you should water, but only enough to
keep the crown alive —about ¼ inch of water).
- Mow at 2-3 inches. So that grass plants can produce enough food
via their green “leaves,” do not mow less than 2 inches high. A longer lawn
better shades its roots to conserve water and roots are hardier since they have
access to more food generated by the green leaves. Also, never remove more than
1/3 of the plant height during any one mowing, or the lawn will be stressed.
(If the lawn gets very tall, split the mowing into 2 sessions a few days apart.
The first one takes off the top inch or so, and the subsequent mowing takes off
- Leave clippings.
Many people think that clippings promote thatch. Not true. Clippings are about
80% water, so will reduce to almost nothing. Thatch is made up thicker
materials like stems and roots, not clippings.
- Test soil.
To make sure that your lawn soil is optimal, you can have a lab test it. To do
that, wait until the soil is above 50°; take your sample 2-4 inches down (not
at the surface); and take several samples around the yard, mixing them together
to submit about 1 cup of soil for the test. (The U of I Extension can refer you
to labs in this area.)
- Treating salt damage.
Most gardeners routinely spread gypsum to counteract road salt. However, gypsum
only works if the “salt” is sodium chloride. Since Lincolnshire uses a mixture of calcium chloride, beet juice, and sodium
chloride (the mixture depends on circumstances), applying gypsum is appropriate
in our village.
- Lawn problems can be diagnosed by “indicator weeds.” Prostrate spurge and knotweed grow in compacted soils,
while creeping Charlie, violets, and nimbleweed grow in shady areas with poor
drainage. Soils with poor fertility seem to generate white clover, and
- Use herbicides for the weed stage. Pre-emergence
herbicides form a barrier and kill weeds as they come out of the seed. Because
of that, if you use such a weed-killer, do not dig or cultivate after it is
applied or you will break the “barrier” and allow weeds to come through. The
best timing is late April/early May when the soil is about 55°. The other kind
of herbicide is post-emergence – these kill broadleaf weeds when they are
actively growing. Always read and follow label instructions exactly
(technically, herbicide labels are a federal legal document!).
There are two optimal times to fertilize a lawn, if fertilizing is needed.
While it is not necessary to fertilize (esp. if leaving clippings to decompose
and provide nutrients to the turf), some gardeners prefer to do so. The optimal
time? Fall when the grass is no longer growing (you no longer need to mow) and
the air is cool (about 45-50°). Late season fertilization feeds the roots,
leading to early spring greening with flush growth. Another good time to fertilize turf is early
spring. (Just remember, do not buy fertilizers with phosphorus—make sure the
middle number on the bag is 0.)
by Ellen Strauss
of us are uneasy planting ornamental grasses, because we’ve seen such big out-
of -control clumps in neighboring yards.
To understand why some spread and some remain in their place, one has to
understand how grasses grow. All grasses, including lawn grasses, grow
by means of creeping rhizomes (underground stems.) New shoots will arise at
intervals along the rhizome as it pushes along under the soil. Some rhizomes
grow quickly and the shoots are spaced at long intervals along it, this grass
forms an interwoven mat or turf, and is very desirable for lawn grasses.
Ornamental grasses may also have shoots at long interval spacing, which however
may be undesirable, as they will spread rapidly and become unsightly,
especially in the garden.
are also classified as warm season and cool season. Cool season grasses green
up quickly in the Spring, and rest during the heat of Summer. Warm season
grasses get a later start, however, stay green in the Summer heat, and flower
examples of these running ornamentals grasses are: Japanese Blood grass (Imperrata cylindrica), Chinese silvergrass (Miscanthus sinensis), Crimson fountain grass (Pennisetum setaceum), and
Prairie Cord Grass (Spartina pectinata) all
of which can become invasive and take over the garden.
grasses produce very short rhizomes with shoots stacked up one on top the next.
These are clumping or bunching grasses which expand slowly and are much more
desirable in garden plantings.
examples of bunching grasses are: Big
Blue stem (Andropogon gerardii), Side
Oats Gramma (Bouteloua curtipendula),
Blue Gramma or mosquito grass (Bouteloua gracilis), Northern Sea Oats
((Chasmanthium latifolium), Purple Love Grass (Eragrostis spectabilis), Switch Grass(Panicum virgatum),and Little Bluestem (Schizachyrium scoparium.) These clumping grasses are all native to Illinois, and are warm season grasses. Prairie Dropseed (Sporobolus heterolepis ) is a clumping
grass of intermediate season.
variety one might also consider grass-like plants such as Sedges (Carex spp.), or Rushes (Juncus spp.) in the mixed garden.
Sources: 1) University of Illinois
Extension, “Horticulture, Native Plant
2) Horticulture Magazine. Oct./Nov. 2009 “Native
Grasses” by William Cullina
3) U of I Extension web site: http//web.extension.illinois.edu/lake/hort_env.html