Fall seeding
 Establishment of turfgrass areas is most commonly accomplished with seed,
although sod can be used. Sod offers the advantage of an "instant lawn" whereas
seed takes much longer to produce a green turf. Establishment with seed is much less
expensive and is surprisingly less complicated than with sod. But in no way is
establishing a lawn with seed an easy task that should be taken lightly. Following proper
establishment procedures can produce a healthy turf that one can be proud of for many
years to come.
Time of Seeding
The best time to seed a lawn is in the late summer to early fall. Adequate
soil moisture, warm soil, and limited weed pressure allow for excellent seedling growth.
Between August 15 and September 15 is optimum seeding time in the northern half of
Indiana; from September 1 to September 30 is optimum in the southern half of Indiana. It
is critical to seed as early as possible within these windows. Even when seeding within
these windows, waiting one week later to seed may mean the stand will take two to four
additional weeks to mature. Establishment in the spring is possible but not as effective
as fall seeding.
Watering
 Seedlings are very
susceptible to desiccation, and the seedbed should not be allowed to dry. A newly seeded
lawn will need to be irrigated two to four times daily depending on the weather. Enough
water should be applied to moisten the top one to two inches of the soil profile, but
avoid over-watering and saturating the area. Once the seedlings are two inches high,
gradually reduce the frequency of irrigation and water more deeply. After the turf has
been mowed two or three times, deep and infrequent irrigation is most effective.
Mowing
Mowing a new lawn will encourage the turf to fill in quickly. Mowing
should begin when  the first few seedlings are tall
enough to mow. You may only mow 10% of the plants in the first mowing, 20-30% of the
plants in the second mowing, and so on. Most wait too long to mow a newly seeded lawn, so
mow early and often. Initially mow Kentucky bluegrass, perennial rye, and fine fescue at
1.5 inches and tall fescue at 2.0 inches. After the first three to four mowings, you can
adjust your mower to the permanent mowing height which is 2.5 -3.5 inches for Kentucky
bluegrass, perennial rye, and fine fescue and 3.0 - 4.0 inches for tall fescue. As always,
never remove more than 1/3 of the grass blade at any one mowing.
Fertility
New seedlings have poorly developed root systems and thus they cannot
effectively absorb nutrients from
the soil. Therefore, it is important to fertilize frequently after seeding to encourage
establishment. Apply 0.75 to 1.0 lb N/1000 ft2 four to six weeks after germination and
again eight to ten weeks after germination. Assuming seeding in mid-August, these
applications would be mid- to late September and again mid- to late October.
Weed Control
There is little weed pressure in the fall so weed control may not be
needed. Broadleaf  weeds may become a problem in the fall, but these can be easily controlled
with a broadleaf herbicide application in October or November, after the third or fourth
mowing. Annual grasses such as crabgrass can be easily controlled with pre-emergence
herbicides applied in the spring.
Spring seeding
The best time to seed a lawn is in the fall (mid-August to mid-September). Seeding in
spring is very difficult and often unsuccessful. However, there are circumstances that
warrant a spring seeding:
 Thin turf due to winter damage
Poor turf density due to poor recovery from previous year's problems, i.e., grub
damage, drought damage, etc.
To make your spring seeding most successful, you must:
Seed as early in the spring as possible to maximize the competition of turfgrass
over crabgrass. Dormant seeding or early April seeding is preferred.
Maximize seed-soil contact through good soil preparation.
Irrigate often as soon as temperatures favor germination (soil temperatures
above 55oF). As root systems develop, gradually reduce frequency but increase duration of
irrigation. Continue irrigation throughout the summer until an adequate root system is
established.
Control weeds in the lawn because spring germinating weeds will out compete the
desirable turfgrass and may kill the turfgrass.
Dormant Seeding
If a spring seeding is necessary, consider doing it before the frost comes out of the
ground. This is defined as "dormant seeding" because the seed will lie dormant
until the soil temperatures warm in April or May. Depending on your location in Indiana,
dormant seeding can be done as early as Thanksgiving and as late as March. The benefit of
dormant seeding is that as the soil heaves and cracks during the winter, crevices are
created for the seeds, which create ideal germination conditions. Additionally, dormant
seeding is easier to schedule than spring seeding, because spring rains make it difficult
to seed after March in Indiana.
Weed Control Guidelines
Perennial grassy weeds (nimblewill, creeping bentgrass, etc.) are not
effectively controlled in the spring with glyphosate (Roundup or Kleen Up). Plan this type
of renovation for the late summer.
Avoid using broadleaf herbicides in newly-seeded areas until the new seedlings
have been mowed at least three times.
Avoid using pre-emergent crabgrass controls (except those containing siduron) at
the same time as a spring seeding. As a general recommendation, delay the use of these
materials until the new seedlings have been mowed four to eight times, depending on the
herbicide. Check the label of the specific crabgrass control material for the exact
recommendations. As mentioned earlier, siduron is an exception to this rule. It can be
used at the time of seeding, but will only control crabgrass for 3 or 4 weeks.
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