Spring has sprung and our lawns
are waking up from their winter rest. Some garden
centers have already had lawn products on display for
several weeks. Your competitive next-door neighbors may
have already purchased turf fertilizer or perhaps a
weed-and-feed product in their annual pursuit of the
greenest, most perfect lawn on the block...as early as
Lawns provide our landscapes with
aesthetic beauty and the functional benefits of an
outdoor carpet, while providing a cooling effect in
summer and reducing erosion. However, in the effort to
create the perfect lawn, many products are applied that
are either unnecessary or ill-timed and are therefore
So, grab the “Lawn Ranger” next door
and let’s talk first about the what, when and how of
spring lawn care, including scalping, dethatching,
fertilizing, weed control, pest and disease management,
watering and aerating.
Scalping is the practice of
cutting the lawn as low as you can to remove the old,
mostly dead top growth. Bermuda and zoysia lawns can
regrow from rhizomes below the soil surface and
therefore can be scalped lower than St. Augustine and
centipede lawns that only have above-ground runners.
Scalping can result in an attractive lawn when the
new growth fills in but has its disadvantages. It
creates a lot of clipping waste that should be removed
and utilized in composting or mulching elsewhere in the
landscape and garden. It also opens the soil surface to
sunlight, which increases the opportunity for weed seeds
to get a foothold.
The bottom line is that
scalping is an unnecessary practice for a well-managed
lawn, and so I generally don’t recommend it. If you
choose to scalp, do so at the end of winter prior to the
emergence of new spring growth.
Thatch is a
buildup of difficult-to-decompose, above-ground plant
parts, such as stolons or runners. Clippings decompose
rapidly and seldom contribute to thatch buildup. A
well-managed home lawn in Texas generally will not have
a thatch problem. If you promote excessive growth by
overfertilizing and overwatering, especially with
Bermuda and zoysia turf, thatch can become an issue.
There is also some evidence that overuse of fungicides
can play a part. If your Bermuda or zoysia turf has a
thick layer of thatch, it is best to hire a professional
with a vertical mower to remove it, while you sit and
watch...and promise to stop overwatering and
St. Augustine, Bermuda, zoysia, buffalo and centipede
are slow to wake up from their winter rest. People often
try to get them going faster with an early
fertilization. However, when your St. Augustine lawn
begins growth in the spring, it is primarily using
nutrients stored in the plant. In time, it begins to
send out new roots to replace the older ones that are
dying off. Therefore, if you apply fertilizer in late
winter to early spring, a significant portion of the
nitrogen, which promotes growth and green color, can be
lost to runoff from rainfall. Or the applied nitrogen
can leach below the root zone before the grass has
developed new roots to take it up.
dates can be a general guide for when to fertilize (such
as mid-April in central parts of the state or early
April in the southern third), not all spring seasons are
the same every year. The best time to make your first
fertilizer application is when you have mowed the
turfgrass twice (mowing winter weeds doesn’t count). By
that time, the grass is growing rapidly and has the new
root system to take up the applied nutrients.
When you fertilize, apply about 1 pound of nitrogen per
1,000 square feet of lawn area. Divide the first number
on the bag into 100 to get the pounds of fertilizer
product to apply per 1,000 square feet. A mid-spring
and/or late-summer application is generally adequate for
home lawns. Recycling clippings back into the lawn also
provides nutrients over time.
Choose a fertilizer
based on a recent soil test. In the absence of a soil
test, use a product with about a 3-1-2 or 4-1-2 ratio of
nutrients. Examples of 3-1-2 fertilizer include 6-2-4,
15-5-10 and 21-0-0. Don’t get hung up on exact numbers.
Just aim for the general ratio and use the advice above
to determine how much you apply.
ratios are best guesses when you haven’t had a soil
test, you may find that your lawn simply needs nitrogen,
or perhaps nitrogen and a little potassium. Phosphorus
tends to tie up in the soil and stick around a long
time. In one northwest Austin neighborhood we tested,
not one lawn needed phosphorus! So, it’s best to use
soil-test results, rather than just buying something
because it says “lawn fertilizer” on the label.
applications are often ineffective because they are
applied at the wrong time or misapplied, or an
inappropriate product is used. As a result, weeds aren’t
controlled, turf or other landscape plants can be
damaged, and the chemicals can wash off into surface
and/or underground water supplies.
The best weed
control strategy is to build a dense turfgrass by proper
mowing, watering and fertilizing. If the lawn is thin,
weeds will become a problem. An old adage states,
“Wherever the sunlight hits the soil, nature plants a
weed.” If your lawn just has a few weeds, you may choose
to do some hand pulling or to “mow and ignore” while you
build turf density over time.
controls all lawn weeds. It’s best to identify which
type of weed you are dealing with so you can choose a
product and application timing that will be effective.
Weeds may be divided into: 1) annuals, biennials or
perennials, 2) cool-season or warm-season plants, and 3)
broadleafs, grasses or sedges.
herbicides prevent weed seeds from sprouting — some can
kill very tiny seedlings — while postemergence products
kill existing weeds. Some are better against grassy
weeds, others control sedges, while still others are
more effective against broadleaf weeds.
are applying a preemergence product for warm-season
weeds, you should make the first application in early to
mid-February in the southern third of the state, and by
early March in North Texas. Cool-season weeds sprout in
the fall, so preventive applications should be made in
early September, as a general guide. Follow the label
carefully for application rates and note that a light
irrigation should usually follow application to move the
product down into the soil surface, where the seeds are
waiting their debut!
products are popular but aren’t the best way to manage
weeds. If they contain a preemergence herbicide, the
problem is that in the spring, the time to weed is not
the time to feed! So, do you apply it early to prevent
warm-season weeds or do you apply it months later when
the grass can best utilize the nutrients? Others contain
herbicides that work on existing weeds, but may or may
not have the best ingredient(s) for the weed species in
your lawn. Some products that control existing broadleaf
weeds can damage St. Augustine when temperatures are
above the mid-80s.
Now all this may seem
confusing, but the bottom line is to know what type of
weeds you have, choose a product that will control them
and apply it at the appropriate time. Your County
Extension Office or a trained nursery professional can
assist with weed identification and product selection.
generally no need for insecticide applications at this
point in the season. Chinch bugs are a mid- to
late-summer problem and grub treatments, if needed,
aren’t applied until June or early July (from South to
North Texas respectively).
The primary disease
concern at this point in the season is take-all root
rot. No treatments should be made unless the disease is
diagnosed in your lawn and an appropriate product is
general guide, lawns in full sun require about half an
inch of water per week in spring and fall, and one inch
per week in summer. Depending on where you live in
Texas, rainfall can supply much of this water.
Overwatering and watering too frequently promote
diseases and shallow rooting, which will come back to
haunt you when things get really hot! When you water,
wet the soil at least 6” deep by splitting the
irrigation cycle into two or more applications spaced
about an hour apart to prevent runoff.
Areas compacted from foot traffic
will benefit from aerating. Most home lawns do not get
enough foot traffic and compaction to need aeration. The
aerators available in most rental companies “push” a
solid tine into the soil, which compacts the soil around
the aeration hole. It is better to use a hollow-tine
aerator that removes a 1/2-inch core of soil and drops
it on the surface.
You may need to hire a
professional with such equipment, if aeration is needed.
Aeration can help reduce compaction, promote root
development and speed the decomposition of thatch. If
you aerate, wait to apply preemergence herbicides until
after you aerate because the process disturbs the soil
These tips should get you on your way to
a beautiful lawn, while protecting the environment and
avoiding wasting your gardening dollars in the process.