Lawns, flower gardens and vegetable gardens are
under a constant attack from weeds. You can never get rid of them
for long. And, they keep coming back.
Most of us simply handle weeds in our lawns with a "Weed and
Feed" fertilizer application once a year. If applied correctly, at
the right time, and with no rain for a day or two after application,
this tends to be quite effective on a wide variety of weeds.
Some persistent weeds require stronger and repeat application of
weed killers. For this, there are a variety of weed killers that can
be mixed in a sprayer and directly applied to problem areas. There
are also spray bottles that you can use to spray individual weeds or
Part of your effective weed control program is a thick and
healthy lawn. If your lawn is thick, it crowds out some weeds and
does not give new weed seeds a chance. So, put your lawn in the best
position to beat those weeds. You may even find that on occasion,
you can skip an application as your healthy lawn is weed free!
A few of us go after persistent weeds by hand. There's that one
little dandelion that pops up a couple of weeks after the weed
killer was applied. Or, a small patch of ground ivy that resists the
weed killer. If you are going to attack a few weeds by hand, make
sure to pull out the weed and all of the roots. Take a bag of grass
seed with you. Generously sprinkle some grass seed on the spot so
new weeds will not be able to take over.
[BACK TO QUESTIONS]
In the cycle of nature, plants and
animals have an important, make that vital, interaction. Our High
School science class taught us that animals and humans breathe in oxygen
and exhale carbon dioxide. Conversely, plants take in carbon dioxide
and emit oxygen. It's a perfect match. A lesser known fact that seems
to escape us in High School is that plants need oxygen, too.
The roots of plants needs water, nutrients, and
...oxygen. Oxygen is held in the spaces between the particles of the
soil. In sandy soils, there are a lot of spaces, and therefore, lots
of oxygen in the soil for your plants' roots. Oxygen is plentiful in
soils rich in organic matter, too.
On the far side of the spectrum, however, are clay
soils, and soils that have been compacted due to high traffic,
or.....lawn rollers, perhaps! In these situations, there is little
oxygen in the soil. Water and nutrients have a hard time getting
down through the soil to the roots of your lawn where it is needed.
The solution to this problem is aeration. The most
common means of providing lawn aeration is a rolling device towed
behind a garden tractor that has many spikes which pierce the soil
and create thousands of small holes in your lawn's soil. Another common
aerator variation is the type where the many spikes have a hole in the middle
of them. As the roller goes
across the lawn, the hollow spikes pick up "plugs" of turf.
Both aerating machines open
passageways for water, nutrients, and oxygen, all of which improve
your lawn's health.
How do you know if your lawn needs aeration? The
first clue is the type of soil. Lawns grown in clay soils (extremely
common in SW Ohio) typically will benefit by regular aeration.
Second, if water sits on your lawn for long periods of time, or
drains away with little seeping in, your lawn will benefit by
aeration. Third, if you are properly caring for your lawn, but it
just doesn't have the color and vitality you expect, aeration is
likely in order. Aeration of the soil breaks up the thatch, and
allows it to decompose naturally, providing further nutrients to
AA LAWNMAN Lawn Care recommends aeration for a
healthier lawn, and we regularly provide aeration service to our
customers who request it.
Here are some mowing tips and
instructions that you will find useful, especially if you are a new
1. Cut lawns when it reaches 2-3 inches in length.
2. Cut no more than 1/3 of the grass blade length at
3. Alternate cuttings, going horizontally and
vertically across the lawn. For a neat look, cut the lawn
4. Leave grass clippings on the lawn to decompose.
As they decompose, they provide natural, organic nitrogen to the
lawn, keep moisture in, and helps to minimize weeds.
5. Always mow when the lawn is dry. This will save
wear and tear on your mower,. It will also keep cut grass from
clumping on the lawn, and minimize the spread of disease.
6. Check the mower blade regularly to assure a sharp
cut. Dull blades will hack and chop the blade, leaving unattractive
ragged, brown edges, and risking lawn damage.
7. Mowing your lawn at a longer length provides a
longer grass blade to absorb sunlight and photosynthesis, helping to
create a healthier lawn. High mowing, as it is called, also helps
block out crabgrass and weeds.
8. If you just can't find the time to fit mowing
into your schedule or for any reason you are not able to care for
your lawn yourself, call us! We provide expert mowing, trimming, and
driveway, sidewalk, patio and porch clipping cleanup with every
mowing job, and our prices can't be beat!
Copyright © 2003
Regents of the University of Minnesota. All rights reserved.
Susan H. Barrott, Horticulture
"Mulching" describes the time-honored practice of covering soil
with a layer of material that will provide a variety of beneficial
gardening results. Mulch can limit weeds, conserve soil moisture,
moderate soil temperature, decrease soil compaction and may also
reduce the spread of some soil-born diseases. Mulching materials may
be organic, from living sources such as wood chips, or inorganic,
such as plastic sheeting. Over time, organic mulches can help build
a better soil structure that pays off in healthy, vigorous plants
that may be better able to live with insect and disease
No single material is the best "all-purpose" mulch for every job.
The locations most often mulched include landscaped areas with trees
and shrubs, perennial borders, annual flower beds and vegetable
gardens. Matching materials, mulch depth and timing of application
to the specific areas in your yard can ensure you get the most
benefits from mulching.
The most effective landscape mulches should not require annual
replacement or extensive maintenance. Trees and shrubs in landscaped
areas need mulches that can reduce weeds and are easy to maintain,
conserve soil moisture, reduce compaction and moderate soil
temperature. Mulching can help keep equipment such as weed whippers
and mowers away from trunks and stems, which in turn reduces bark
Because of their permanent nature and high visibility, more
expensive materials that are slow to break down are often used in
landscaped areas. Wood chips or shredded bark work well. Apply
finely shredded wood chips 2 to 3 inches deep. Coarse textured bark
and wood chips can be applied to a maximum depth of 6 inches;
exceeding that depth will begin to block the flow of oxygen in and
out of the soil. Keep mulches a few inches away from all trunks and
stems so you don't provide a place for insects or diseases to begin
attacking the plants.
Wood chips or shredded bark are often used on top of landscape
fabric to achieve better weed control. Woven or layered landscape
fabrics are made of various combinations of synthetics, such as
plastics or vinyls, and allow air and water through while keeping
light and weeds out. Rock can also be used to top-dress fabric, but
may absorb enough sunlight to alter soil temperature unfavorably. Do
not use solid plastic sheeting because it creates a barrier to the
movement of air and water in and out of the soil, and bark has a
tendency to slide off it in heavy rains.
Perennial borders are often located within or adjacent to
landscaped areas; many of the same materials are suitable for both
areas. Spread mulch 2-3 inches deep--enough cover to limit soil from
splashing up onto to the undersides of the plants in order to reduce
the spread of soil-borne diseases.
Annual flower beds do best with organic mulches that will break
down rapidly when tilled into the soil at the end of the season.
This adds organic matter to the soil, provides food for earthworms
and helps builds a healthier soil structure. If annuals are directly
seeded into the bed, wait until they are several inches high and you
have weeded at least once before applying 1 to 2 inches of mulch.
Shredded leaves, partially decomposed compost, grass clippings or
cocoa bean hulls are all easy to turn in at the end of the season.
Vegetable gardens often produce larger and healthier crops when
mulched at the correct time. Wait until the soil has warmed
thoroughly for heat loving crops, but mulch cool season crops early
in spring. Two to four inches of chipped leaves, partially
decomposed compost, dry grass clippings and straw are all excellent
choices for vegetable gardens. Mulched soils are less likely to
compact and will stay evenly moist, which encourages root system
development and can help contribute to increased yields.
Black plastic mulch is excellent for pre-warming cool spring soil
for heat loving crops such as eggplant, melons, peppers, squash and
tomatoes. Put the plastic in place one or two weeks before planting.
Covering the plastic with a reflective material such as straw later
in the season will ensure the temperatures don't get too high and
"cook" the roots. You must punch holes in the plastic to allow water
penetration or water adequately through the planting holes.
Mulching materials are available at your local yard and garden
center and through some catalogs. Many municipalities also have
compost available to the public. Compost can be made easily in your
own backyard. See the Extension fact sheet AG-FS-3899 Backyard
Composting, available from the Extension Distribution Center
(612-625-8173), or search under "backyard composting" on our
http://www.extension.umn.edu for further information on
[BACK TO QUESTIONS]
Controls weeds effectively
Moderates soil temperature
Blocks soil splash
Adds organic matter
High annual maintenance
Partially Decomposed compost
nutrients and builds soil structure. Excellent mulch
material. Highly recommended for use on annual, vegetable
and perennial gardens.
for earthworms and builds soil structure. Excellent mulch
material. Highly recommended for use on annual and perennial
mat and block rainfall if shredded too fine.
Cocoa bean hulls
|Has a chocolate
aroma when wet. Recommended for annual and perennial beds.
mat and interfere with water penetration. Can blow away in
exposed areas. May develop an unsightly but harmless white
clippings can be applied at 1-2 inches. Can be used on
annual, vegetable and perennial beds.
residues in clippings may injure mulched plants. Use
clippings from non-treated lawns or wait three mowings
before using clippings.
|Will not cause
a measurable change in soil pH. Best used on perennial beds
as they will last for two or three years.
needles annually from underneath evergreens may eventually
cause nutrient deficiency in evergreens.
Controls weeds effectively
Moderates soil temperature
Blocks soil splash
Adds organic matter
High annual maintenance
mushrooms or other fungal growths is common, but not
harmful. Has little effect on soil nitrogen when on the soil
surface. Best for permanent landscape plantings. Can be used
on perennial beds.
into the soil, chips will soak up high amounts of available
nitrogen. Compensate by adding a high nitrogen fertilizer
when you incorporate it.
must be added every two or three years. Has little effect on
soil nitrogen when on the soil surface. Best for perennial
and landscape plantings.
||Will soak up
large amounts of nitrogen if worked into the soil.
Compensate by adding high nitrogen fertilizer when you
|Good mulch if
composted before it is applied.
fresh, it will cause nitrogen deficiency in the soil, which
can affect plant growth. Adding excessive nitrogen to
compensate may burn plants.
splash off vegetables which may decrease soil-borne
diseases. Chopped straw is easier to handle and turn in at
end of the season.
||Must be free of
weeds so it doesn't introduce weed seeds into the garden.
effective with low maintenance for several years after
dressing with more attractive material. Deteriorates after
Controls weeds effectively
Moderates soil temperature
Blocks soil splash
Adds organic matter
High annual maintenance
expensive, but very effective and easy to use. Can be tilled
in at end of the growing season.
use in large areas.
|Strips of paper
allow better water penetration and don't blow away as easily
as large sheets.
slippery when wet for extended periods. Not recommended for
used to raise spring soil temperature for heat-loving crops
like melons, tomatoes, peppers and eggplant. Punch holes in
the plastic to allow water and air penetration.
temperature may be too high for cool-season crops like peas,
cabbages, spinach and lettuce. Should be covered with a
reflective material like straw mid-season to keep the soil
temperature from damaging roots of all crops, including
warm- season ones.
|Works well to
raise soil temperature in spring. (See disadvantages.)
as weeds will grow under the plastic and soil temperatures
are likely to rise high enough to damage plant roots.
Grasses require at least 16 different essential
elements in their diets, most of which are available from the
plants' surrounding environment. But the growth demands of today's
lawn owners usually mean that homeowners must help Mother Nature
Even if you are committed to having a low-maintenance lawn, you
will need to fertilize it with nitrogen (N) to sustain thick,
vigorous turf. In addition to bringing on deep green color, nitrogen
is responsible for the sturdy growth and shoot density needed to
fight off weeds and to stand up to disease, insects, and traffic.
All of these positive effects can easily turn into negative ones
if you use too much fertilizer or apply it at the wrong time. The
common practice of fertilizing in the early spring is actually
not the best time in northern climes. It not only encourages excess
blade growth which means more mowing, but it also gives your weeds a
boost and increases thatch! Excessive spring growth also produces
thin-walled grass blade cells that are more prone to injury and
disease. Late summer to early fall is the preferred time for feeding
northern lawns; mid-spring in the South.
In addition to needing nitrogen, your lawn may need phosphorus
(P) and potassium(K). Depending on where you live, your soil may
naturally contain adequate levels of these elements. Aiding in root
growth and improving establishment rates, phosphorus is needed in
small amounts and tends to remain in the soil. Potassium plays an
important role in enhancing your grass's resistance to cold,
disease, drought, and wear and is more prone to leaching from the
soil. A soil test will help you determine which nutrients your soil
A fertilizer with the designation "complete" contains all three
of these nutritional elements. The percentage of the bag's contents
made up respectively of nitrogen, phosphorus, and potassium, can be
found by looking at the fertilizer grade. These three prominent
numbers also tell you the percentage of nitrogen to phosphorus to
potassium. For example, in a 50 pound bag of 20-10-10 grade, the
ratio is 2:1:1, which means that 20 percent of the 50 pounds, or 10
pounds of the bag, is actual nitrogen; 10 percent (5 pounds) is
phosphorous; and 10 percent (5 pounds) is potassium. The remaining
30 pounds of material in the bag may consist of additional elements
such as iron and sulfur, as well as inert "filler" ingredients.
Fillers are used to help ensure even distribution of the product and
are frequently made from organic materials such as finely ground
Ratios are helpful in choosing which fertilizer to use for
specific purposes. Those with a 1:2:2 ratio, such as a 6-12-12
fertilizer, are lower in nitrogen but higher in the nutrients
desired when planting new grass or renovating old lawns. Fertilizers
with high-nitrogen ratios of 2:1:1, 4:1:2, or 3:1:2 are frequently
used for maintenance applications. They contain N, P, and K
quantities closer to the plant's ongoing needs and are available in
grades of 12-6-6, 16-8-8, 20-10-10, and so on.
While considering which bag of fertilizer is most appropriate for
your yard, be sure to read the back label for the guaranteed
analysis of the contents. If your soil test indicates that you don't
need to add phosphorus or potassium, choose a bag with a low numeral
or zero for that element. For example, a bag of 20-0-5 would have no
phosphorus. In addition to checking the grade, you should also
determine what type of nitrogen has been used, "water-soluble" or
Water-soluble nitrogen, once watered into the soil, can be
immediately used by grass plants. Ammonium nitrate, ammonium
sulfate, and urea are examples of this quick-release form of
nitrogen. These provide a rapid green-up, but they also have
Water-insoluble nitrogen, found in slow-release fertilizers, must
first be broken down by soil microbes into forms grass plants can
use. These slow-release sources include synthetic organics, like
ureaforms, or those derived from natural organic materials, such as
composted manures. To spread the release of nitrogen over time,
fertilizer companies can also manipulate the size of particles and
sometimes coat them as well. Because these forms take longer to
dissolve, they release nitrogen at varying rates. Common examples
are isobutylidene diurea (IBDU) and sulfur-coated ureas.
When buying fertilizer, opt for the water-insoluble types or
other slow-release forms. Using slow-release fertilizers will allow
you to reduce the amount of time you spend behind your spreader.
They last much longer and don't have to be applied as frequently as
quick-release fertilizers, saving you money as well as time.
Determine the type of fertilizer you have by reading the guaranteed
analysis on the bag. Note: Many fertilizers have a combination of
both fast-release and slow-release types of nitrogen. You should
check carefully to find products that derive a majority of their
nitrogen from slow-release sources.
The optimal time to apply fertilizers is when the grass roots and
blades are actively growing. In the North this growth season occurs
during the early to mid fall, when weed competition is minimal and
fertilizing produces healthy root growth. This timing also allows
plants to build up needed carbohydrate stores with just a moderate
amount of topgrowth. For northern lawns, you should divide the
annual amount of fertilizer and apply two-thirds in early fall and
the remainder in mid to late spring, after the lawn's initial
green-up. Because the grasses in southern lawns have a larger blade
size and grow more vigorously, they will need at least two
applications of fertilizer each year. Do the first about three weeks
after the initial spring green-up; then fertilize again in late
summer. You can add supplemental quick-release nitrogen between
these times if weak growth and poor color indicate that it's needed.
For low-maintenance lawns, you should be applying 2 pounds of
actual nitrogen per 1,000 square feet per year in the North and 2-4
pounds in the South. This may require an adjustment, given your
specific growing environment, soil test results, the lawn's
condition, and the type of fertilizer you use, whether slow- or
fast-release. You can consult your Cooperative Extension Service for
local recommendations. Quick-release fertilizers are usually applied
at a rate of 1 pound of nitrogen per 1,000 square feet. Slow-release
fertilizers usually require a higher rate of application to deliver
their nitrogen. Follow the manufacturer's instructions and check the
calibration of your spreader, as well as the square footage of your
lawn, to ensure that you are applying the right amount. Remember,
more is not necessarily better with fertilizers. Applying too much
may "burn" your lawn and promote thatch formation and disease.
Keep in mind that lawns kept under irrigation throughout the
summer or located in areas receiving heavy rainfall will require
more nitrogen than their unwatered counterparts. Sandy soils are
more prone to leach nutrients, but using water-insoluble fertilizers
will help nutrients remain in the soil longer. Leaving grass
clippings on the lawn over the course of a year will add about 1
pound of nitrogen per 1,000 square feet, so you can figure
accordingly. The total amount of nitrogen that you'll need per year
also varies with the type of grass you are growing. For example,
Kentucky bluegrass and perennial ryegrasses require more fertilizer
than the fescues, while in the South, Bermudagrass, zoysiagrass, and
St. Augustinegrass need more than bahiagrass, centipedegrass, or
[BACK TO QUESTIONS]
Fungicides Fungicides have been the
traditional means of treating lawn diseases. While fungicides do
clear up certain problems, they unfortunately may make turf
vulnerable to new ones. This happens primarily because fungicides
kill off the beneficial, disease-suppressing microorganisms and
fungi as well as targeted organisms. If your disease symptoms
continue unabated and you feel the need to use a fungicide, use it
sparingly and follow the package directions. Of the mineral-based
fungicides, elemental sulfur is considered the least toxic to humans
and is available in a wide range of products.
Look at the Future Nonprofit organizations, such as the
Bio-Integral Resource Center (BIRC) www.birc.org in Berkeley,
Calif., are studying nontraditional ways of preventing and resolving
lawn diseases. These include using neem oil (which contains sulfur
compounds), biological fungicides, and fungicidal soaps. Scientists
are also investigating the potential for disease-prevention roles of
fungi and other microorganisms. Another avenue of research involves
the positive correlation between soil nutrients, such as calcium,
and a grass's resistance to disease. There is much to learn, but we
do know that keeping the complex ecosystem of our lawn in balance is
1. Choose recommended grass seed mixtures. Then if lawn disease
does develop, not all grass types will be affected.
2. Look for
improved or disease-resistant cultivars when renovating or starting
3. Water your lawn only early in the day, from sunrise
until 11 A.M.
4. Water only when needed, and then to a depth of 6 to
5. Maintain adequate lawn aeration and drainage.
cut off more than one-third of the grass length at one time.
mower blades sharp.
8. Keep thatch to 1/2 inch in height.
appropriate fertilizer, and correct nutrient deficiencies,
10. Prune and thin trees and tall shrubs to
increase air circulation and sunlight exposure.
Using Compost: Research has shown that microorganisms present in
at least one-year-old organic compost can suppress turf grass
diseases. Scientists at Cornell University note that effective
control of dollar spot, brown patch, and gray snow mold can be
achieved with monthly applications of such "suppressive" compost.
Additionally, regular topdressing also lessens the severity of
pythium blight and necrotic spot infections.
Although the theory is still under investigation, plant
pathologists believe that the presence of "antagonistic"
microorganisms in these aged organic materials are what help them to
suppress disease. Usually fungi, they are called antagonistic
because they have an adverse impact on disease-causing
microorganisms. They kill them, damage them, or out-compete them for
food and habitat resources.
Recommended suppressive topdressings include composted manures,
pulverized tree bark, leaf compost, composted garden debris, sludge
(such as Milorganite), or agricultural wastes. Amending mature
organic composts with commercial "innoculants" that contain
beneficial microorganisms yields even greater disease suppression.
Current researchers are working to identify which microorganisms
fight which pathogens in hopes of creating products formulated to
ward off specific diseases. In the meantime, topdressing with a
1/4-inch layer of well-aged compost one in early spring and again in
fall may not only help to decrease your thatch layer, it might also
give your lawn the added nutrients and microorganisms it needs to
keep disease at bay.
FALL LAWN CARE TIPS
While many homeowners look forward to less time
behind their mower at the end of the summer, fall provides an
opportunity to set the conditions that will give your lawn a head
start come next spring. Cool-season lawns benefit the most from fall
activities such as fertilization and aeration while moderate
fertilization and weed control help increase spring vitality for
Fertilize Responsibly: Cool-season grasses benefit the most from
fall fertilization, as the turf is busy storing energy during this
time that will help the lawn over winter and spur spring growth. Dr.
Van Cline, agronomist for The Toro Company, recommends applying two
thirds of the annual nitrogen fertilizer requirement during the fall
season for cool-season lawns.
The opposite is true for warm-season grasses, as they require
greater quantities of nutrients during late spring and early summer
when they are most actively growing. Cooler fall temperatures
provide warm-season grasses the opportunity to increase root
production while overall shoot and leaf development rates decline.
While nitrogen fertilization is recommended for warm season grass in
the fall, it should be limited to quantities that will keep the
plant active, but not generate succulent growth that has the
potential to foster winterkill.
Your local cooperative extension agent or a garden center expert can
help provide you with the tools necessary to test your soil
fertility and recommend a fertility program that will optimize your
fertilizer applications throughout the year.
Aeration stimulates root growth and improves nutrient uptake. Fall
is the best time to aerate cool-season turf, as the grass plants will
quickly heal from the coring action of the aerator – especially with
the help of fall fertilization and irrigation programs. Aeration
allows oxygen, water, and nutrients to penetrate further into the
soil, encouraging deeper root and reducing soil compaction that
restricts root growth – especially during the hot summer months when
healthy roots are needed to help cool-season grass survive stress
For warm-season turf, aeration is best performed in the late
spring to early summer in conjunction with increased fertilizer
application that help support its active warm weather growth habit.
One of the drawbacks from aeration is the production of cores
that will litter your lawn. While the cores will break down over
time, the use of a mulching mower will help break up the cores more
quickly and provide a ‘topdressing’ for your lawn.
Some weeds are better controlled in the fall. Common, yet
troublesome winter annual weeds such as henbit and chickweed
germinate during the fall and over-winter as juvenile plants. By
applying a post-emergent herbicide in the fall, winter annual weeds
are more easily controlled and won’t have the chance to mature come
Likewise, perennial broadleaf weeds such as dandelion and clover
will also have a flush of vegetative growth during periods of cooler
temperatures. Controlling these weeds in the fall will help improve
overall turf density while reducing spring weed populations.
Remember that not all herbicides are lawn-safe. Choose a
herbicide that is effective against the types of weeds present in
your lawn. The product label is your guide to effectiveness,
application rate and timing and, most importantly, safe use and
WHAT KIND OF GRASS SHOULD I PLANT?
Choosing the right grass for your yard can make
the difference between having a low-maintenance,
environmentally-friendly lawn and one that is susceptible to
disease, pests, and weed invasion, and that requires a lot of
upkeep. The type of seed you choose for either a new or restored
lawn should depend on several factors.
1. What do you want your lawn to look like? Grasses vary in
color, leaf width, habit (characteristic appearance), and density of
2. How much time and money are you realistically willing to spend
tending your lawn. Higher-maintenance grasses mean higher cost and
3. Your seed choice will be affected by your site's growing
conditions: the amount of sun and shade your site gets, the soil
type and its level of fertility and dryness or wetness, and your
4. Consider how your lawn will be used: for decorative
landscaping, for erosion control, or as a play area.
There are two ways to purchase grass seed. You can visit the garden
section of a retain store and pick out a package labeled with
intended use, such as "Shade mix." Or, you can buy the latest
cultivars and make up your own mix. For this you will need to nose
around, starting with a good nursery. If the nursery doesn't carry
what you want, staff there can probably suggest where to shop.
Calling the customer service departments of the large seed producers
should also yield results. Either way, you will still need to know
the basics about purchasing seed, beginning with the terms species
The word species refers to a group of closely related plants that
differ from one another in only minor ways. Tall fescues are one
species of lawn grass. The various members of a species are called
varieties (which originally occurred in nature) or cultivars
(variations that came about in cultivation, as a result of
deliberate breeding). In common usage the terms variety and cultivar
are often interchanged, but there is a difference between them.
Grass cultivars include old standbys, such as the tall fescues,
'Alta' or 'Kentucky 31', as well as new and improved types that have
been bred and chosen for superior characteristics. Newer grass
cultivars, in most cases, are highly recommended.
Many people are familiar with common grass names such as Kentucky
bluegrass. In addition, grass plants (like all plants) have two-part
botanical names. While the mere use of such scientific names makes
most people tune out, the fact is, they can be helpful, even to
First, botanical names pop out because they are usually
italicized or underlined. The first italicized word, the genus, is
capitalized and indicates a group of species that have similar
structural parts. The second italicized word is the species, which
is not capitalized, and indicates similar plants that can interbreed
true to their parents. Knowing that Kentucky bluegrass is also
called Poa pratensis allows you to identify other plants from the
same genus and species. This is because their botanical names will
also include the genus, Poa, and the species, pratensis.
Botanists take plant names one step further by assigning
individual plants a third name that shows if they are a variety or
cultivar. Varietal plants develop in nature, through natural
selection. The varietal name follows the genus and species and is
frequently seen italicized after the abbreviation var. For example,
Poa pratensis var. Park is another name for Park, one of the
original Kentucky bluegrasses.
With today's push to create improved grasses, you are more apt to
come across plants that are cultivars, meaning they were created
through deliberate breeding. Cultivar names also follow the genus
and species but are enclosed in single quotes and are not italicized
or underlined. If you were to see Poa pratensis 'America', you would
know that you were dealing with a cultivar of Kentucky bluegrass
Cool-season grasses are frequently packaged in either a mixture
or a blend. Mixtures have two or more species of grass, and blends
contain two or more cultivars of the same species. There are many
advantages to planting a mixture or blend. For one thing, the turf
will be more resistant to diseases and pests, because each cultivar
or species has its own strengths and weaknesses. And since most
lawns have a variety of growing conditions, the different grasses
can grow where they are best adapted within your lawn.
In a typical mixture containing bluegrass, ryegrass, and fine
fescue, the fescues will thrive in the shady portion of the lawn,
while the bluegrass will do best in the sunny areas. If conditions
should turn adverse for one of the grasses, you won't lose the
entire lawn, just the part that's made up of the susceptible grass.
Unlike cool-season grasses, warm-season ones tend to be planted
as monostands, meaning that a single type of seed is planted, not a
mixture. Their growth via stolons and rhizomes makes them so
vigorous that other grasses cannot compete. Because of their
distinctive appearance, some grasses, such as the original tall
fescues and most native grasses, also look better planted alone.
Thanks to the passage of the Federal Seed Act of 1936, grass-seed
labeling must meet certain requirements. This allows you to know at
a glance what is in any given box, including what percentage of the
seed will germinate. When you shop for seed, it pays to compare
brands closely and to remember the adage, "the lawn you grow is no
better than the seed you buy". The extra expense for higher-quality
seed is usually worth it. Check the labels and try to avoid mixtures
containing lower-quality grasses, like timothy, meadow fescue,
orchard grass, tall oatgrass, and annual ryegrass. Look also for
cultivars recommended for your area by your Cooperative Extension
While unused grass seed may remain viable for years, its rate of
germination will decrease over time. Be sure to keep seed stored in
a cool, dry environment. To maintain optimum viability, the rule of
thumb for storage is that the temperature and the relative humidity
added together should be less than 100.
Every grass seed package is required to have a label listing the
contents. Here are some tips to help you understand the terms:
- Species and Variety
The label will list the species, or types, of grass seed in the bag
by the common species name as well as by the specific variety name
within the species. For example, "Midnight Kentucky Bluegrass" is
the variety Midnight from the species Kentucky Bluegrass. A mixture
of grass seed will often contain more than one species as well as
more than one variety from a given species. Check with your county
extension service or the experts at your local garden center to see
what species mixture is best suited for your specific lawn
The number listed next to the grass seed variety name indicates the
purity of the seed. Purity refers to the percent, by weight, of each
lawn seed in the mixture. You should look for packages with the pure
seed percentage totaling 90% or more.
The germination figure on the label it indicates the percent of pure
seed that has been tested and should grow when planted. The
germination figure should be at least 80%.
- Crop Seed
The crop seed number refers to the percentage of the mixture that is
grown as a cash crop. It is best to find seed with less than .5%
crop seed, as it may lower the quality of your lawn.
- Inert Matter
The inert matter on a grass seed label indicates the amount of the
mixture that is incapable of growth. Think of this as “filler.”
High-quality grass seed contains little inert matter.
- Weed Seed
The weed seed that is listed on the label indicates the percentage
of weeds in the package. It is best to choose mixtures with less
than .5% weed seed. Noxious weeds are extremely problematic for
proper lawn growth and maintenance. To ensure quality lawns, avoid
packages with noxious weeds.
- Test Date
Finally, the test date refers when the seed was last tested. It is
best to choose seed tested within the past nine to 12 months.
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