Spring seeding should be done between March 15 and April 1 for
the best chance of success. The reasons for the early date are
the heat and the long germination time for Kentucky bluegrass.
It can take up to a month for bluegrass seed to germinate. This
means an April 1 seeding might germinate May 1. Then add six to
eight weeks for it to become established. This could then be
close to July 1. Usually we tend to get hot weather by then.
Let's start with the basics. The normal seedings are a blend of
Kentucky bluegrass, perennial ryegrass and fine fescue. The fine
fescue is much better in shade and the perennial ryegrass will
provide quicker cover. The seeding rate is generally 4 pounds
per 1,000 square feet in bare dirt seedings. Use two pounds per
1,000 square feet in overseeding thin lawns. Of course this can
run into some real money when doing very large areas. Many rural
seedings are done more on the basis of a pound per 1,000 square
feet. There are almost 44,000 square feet in an acre, so you can
do the math on this one.
Fertilizer is always an area of many questions. The place to
start is a soil test. This will tell you where you are starting
from. Basic soil test levels for phosphorus, potassium and soil
pH should be in the neighborhood of 40, 350 and 6.1,
respectively. Phosphorus and potassium are on a pound-per-acre
basis. This must be considered if you use labs that report in
parts per million, which will give numbers half as large. These
numbers will provide a great environment for grass. Grass will
really grow in very poor conditions, but it certainly won't have
that manicured lawn look many strive for.
Lacking a soil test, or being at recommended fertility levels,
general maintenance applications provide a pound each of nitrogen,
phosphorus and potassium per 1,000 square feet of lawn area in May
and again in September. Really lush lawns will usually have twice as
much nitrogen applied in a season, but split among four
applications. Hang on to your wallet again this year, as fertilizer
prices have increased dramatically.
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If you decide to try seeding this spring, remember a couple of
things related to weed killers. Number one, you can't use crabgrass
preventer in the same season as you put down seed. The crabgrass
preventer doesn't know the difference between grass seed and weed
seeds. The second rule is to mow the new seeding at least three
times before trying any broadleaf weed killer. Generally this means
spring broadleaf control doesn't happen when you seed in the spring.
The end result is if you seed in the spring, you control weeds in
the fall. Seed in the fall, and you control weeds and crabgrass in
If you do plan to use a crabgrass preventer, time it so
it is on about the time the forsythia blooms. This would be the
approximate soil and air temperature needed for the crabgrass to
germinate. April 1 is a good guess, but this date can vary widely
with the weather. Many crabgrass preventers last only four to eight
weeks, so plan on repeating the application in June anyway.
University of Illinois Extension, Logan County]