Thatch buildup and soil compaction are both conditions that can cause
lawns to struggle. When they are severe, they can ruin a lawn. Luckily,
both are problems that can be resolved. Simply dethatching or aerating
the lawn will provide an immediate fix, but it is also important to
find out what the contributing factors are and make some changes so
that the solution will be long-term, not just temporary.
All About Thatch
What exactly is thatch? It is the layer of debris made up mostly of grass
clippings that accumulates above the soil and below the blades of grass.
This isn't just a thin layer of freshly cut grass clippings. To see it clearly,
simply dig out a scoop of your lawn (don't worry, you can put it right back
when you're done) and look at it from the side. You should be able to clearly
identify the soil, the thatch and the top growth of the lawn grasses. The
thatch layer will look like a tightly knit layer of brown debris. While
thatch is primarily composed of cut grass blades, it also contains the bits
and pieces of leaves and twigs that have fallen onto the lawn. In a healthy
lawn, the thatch layer will decay naturally, providing nutrients for the
lawn. A healthy lawn will have an layer of thatch about a half inch thick.
Having no thatch layer isn't the goal either, because that can make the
lawn more susceptible to drought and heat stress. Thatch not only provides
nutrients, it also helps shade and protect the crowns of the grass plants
and helps conserve moisture. Lawns with a healthy layer of thatch do not
need dethatching.
Sometimes the lawn can have too much thatch. Excessive thatch most
often happens when the lawn is fertilized too often, the grass clippings
are too long or there aren't enough of the microorganisms that digest
the thatch present. Most often, it is a combination of these factors.
When the thatch layer is too deep (in excess of a half inch), the
lawn will begin to thin. Lawns with heavy thatch tend to have a shallower
root system, making the grass harder to maintain. Thatch can keep
water, air and nutrients from getting to the roots. And if that isn't
enough, lawns with excessive thatch are also more likely to have problems
with diseases.
All About Dethatching
Dethatching is the process used to remove the excess thatch. It is
best to dethatch the varieties of grass grown in our area in early
fall. When lawns are dethatched in spring, there is a much greater
risk of damaging the newly awakening grass crowns. If a severe thatch
problem is discovered in spring, you are faced with deciding if more
damage will be done by dethatching in spring or by leaving the thatch
on the lawn for the summer.
When it is time to dethatch, mowing the lawn fairly low just before
starting will make the job easier. If you are up to it, in small areas
remove it by raking back and forth. Hand raking is a backbreaking
way of removing thatch from any but the smallest areas. There are
several better ways to accomplish this task. If the thatch isn't so
severe that it is smothering the crowns of the grass plants (over
an inch deep), consider using a core aerator to solve the thatch problem.
The cores of soil will pull up the microorganisms needed to naturally
digest the excess thatch, turning it into nutrients for the lawn.
For a more serious thatch problem, there are mechanical dethatchers.
These machines are usually rented for the day or many lawn care companies
offer this service. The best type of machine for dethatching is a
vertical mower. It has a row of blades that cut groves into the thatch
and pull it up. The other alternative is a power rake. They are like
lawn mowers with spring tines attached to the blades. Power rakes
work, but they don't pull up as much thatch and they pull up more
grass than a vertical mower, sometimes damaging the lawn.
If you are using a mechanical dethatcher, it is better to set it too
high than it is to set it too low. Since you almost always have to
go back over spots several time the blades can be lowered once you
become accustomed to working with the machine.
Once the thatch is pulled up to the surface, it will have to be raked
up and either composted or disposed of. Do not allow it to sit on
the surface of the grass for very long.
There are also liquid products that can be applied to the lawn to
speed up the breakdown of thatch. They are not as reliable as mechanically
dethatching and should only be considered to aid digestion on a healthy
lawn, not to resolve a thatch buildup problem.
All About Soil Compaction
Plant roots need air in the soil and good drainage. Without it, the
root systems will be shallow and weak. In lawns, signs of compacted
soil include poor drainage (puddling), excessive weeds despite the
use of good weed controls and poor grass growth despite good maintenance
practices. When the soil is compacted, nutrients and water are slow
to get to the roots, further weakening the plants. Soil compaction
is a problem in high traffic areas or where heavy equipment has been
used for construction, grading or even mowing. There are fancy pieces
of equipment that can actually measure soil compaction, but that isn't
really necessary for the homeowner. If you don't know if your soil
is too compacted, you can check it out yourself. Take a sharp shovel
into the lawn and try to dig out a scoop of turf and the underlying
soil. If it isn't a struggle to sink the shovel in at least half way,
you soil isn't too compacted. Look at the sample you removed. There
are probably lots of grass roots that extend 4-6 inches below the
surface. You will be able to see spaces in the soil between the particles
and it will crumble fairly easily. Now, if you have to jump up and
down on the shovel to even get it into the soil, you have a problem.
Look at the sample you removed. There probably won't be a deep, extensive
root system for the grass. It will also look fairly solid and will
be hard to break up. This soil needs aeration.
All About Aerating
Aeration is best done in late summer or early fall. Depending on your
soil type and the traffic on your lawn, it may need aerating every
second or third season. Despite all the claims about aerating your
lawn by wearing spikes attached to your shoes, mechanical core or
plug aerators are the only good way to aerate a lawn. They pull up
a core of soil and leave it on the surface of the soil. This does
the best job. Core aerators can either be rented or many lawn care
companies offer this service. These machines should pull out plugs
that are about the size of your little finger. It may sound like too
many holes, but the aerator should be run back and forth until there
are 20-40 holes in every square foot. The holes allow for air, rain
and nutrients to penetrate the soil better. It also gives the roots
room to grow. The lawn will look rough for a few weeks, but this is
the right amount. Leave the cores on the surface to dissolve over
the next few weeks in the rain. The soil in the cores contains millions
of microorganisms that help digest thatch naturally, creating a healthier
lawn. If we go through a long dry period after core aerating, run
the sprinkler to help break down the cores. Avoid using aerators that
are simply rollers with spikes. Spikes simply push soil aside when
penetrating the soil, adding to the compaction problem.
The up side of core aerating is that it encourages deep rooting, increases
air in the soil, improves water and nutrient penetration, helps break down
thatch and encourages growth of beneficial soil microorganisms. The down
side of core aeration is that it also brings up quite a few weed seeds from
the soil bank. You may want to consider using a pre-emergent herbicide the
following spring to minimize the weed problem.
Flowers and gifts from Bachman’s make any day a special one. When you order your flowers or gifts online, you know you’ll be getting a beautiful fresh flower arrangement from a trusted florist known for outstanding flower design, plus quality and service.
If you’re sending flowers or gifts out of town, you can rely on us to choose the best florist from either the FTD or Teleflora nationwide flower network. Florists who can be counted on to deliver the best fresh flower arrangements and gifts, even when doing a same day delivery.
