In the Auckland City area it is
not uncommon for cool-season lawns to look less than perfect after the
stress of a hot dry summer. Disease, drought, weed encroachment
heat, poor soil or just plan old neglect may mean that it's time for overseeding.
In the Auckland City area cool-season grasses should be treated almost
as though they are hardy at some times and at other times delicate perennials.
In other words, to keep a lawn planted to cool-season grasses looking good
it will probably need at least some overseeding each year.
The optimum time to overseed cool-season turf grasses in the
Auckland City area is during the autumn. This is when nature establishes
cool-season grasses; therefore, the best results with the least amount
of work occur at this time. Do not delay seeding or the grass may
not establish sufficiently before winter allowing winter growing weeds
to become a problem.
If you wish to completely eliminate existing vegetation because
of large infestations of weeds in particular weed grasses such as Paspalum
Species Roundup can be used. Make sure you complete your last
application at least five days prior to seeding.
Do not use broadleaf weed killers one month before seeding or
on new grass until it is well established this will take on average three
months.
Choosing the grass variety to be planted.
In the Auckland area the most frequently planted grass planted
in full sun situations is perennial Rye grass. Perennial Rye grass (Lolium
perene) is winter growing, winter-hardy turf grass capable of withstanding
temperature and moisture extremes. During hot, dry periods it tends to
become dormant and lose colour. If high quality is desired during the
summer period, lawn irrigation is often necessary. Perennial Rye grass
performs best in full sun, for shady areas a mixture of perennial Rye
and chewings Fescue (Festuca nigrescens)usually give the best results.
Bent or common bent (Agrostis capillaris) also known as browntop is to be
found in many cool-season grass mixes planted in this region.
Make sure the grass variety chosen meets your lawn's sunlight
requirements. Grass varieties that thrive in full sun may not grow
well in part-shade. Shade tolerant grasses may wilt and die in sunny areas.
Preparing the Seedbed
Mow the area to as low as possible without scalping to reduce
competition from established grasses. Short mowing helps prevent
the seed from lodging in tall grass and lets light reach the new seedlings.
Use a grass catcher on the mower or sweep up excess clippings.
Do not scalp off all the existing turf - some is needed to protect the
germinating seed from wind, hot sun, and heavy rain.
Planting
The use of a combination verticutter
over-seeder is recommended, this machine cuts vertical grooves into your
soil creating a nice soil to seed contact area. This is followed by a
second set of discs that slice open the ground just ahead of a small tube
that drops the seed into the open furrow. A packing wheel follows the seed
tube and closes the sliced ground. A slit seeder sows grass seeds in distinct
rows the distance apart depending on the space between the drill discs.
It is important to repeat the seeding process at different angles usually
90 degrees to one another.
