A few weeks ago a customer asked us to complete a seeding and aeration this coming spring, if we felt it would be beneficial.
Unfortunately, there is no appropriate time in the spring for a seeding and aeration. Spring seeding is not recommended for the following reasons.
1) A spring seeding would prevent any use of chemical applications for about 3 months. This means no crabgrass preemergent or post emergent herbicide can be applied.
2) Seed that is planted in the spring has about a 50% chance of germinating and surviving. Spring is a very difficult time for grass to grow and become established as spring diseases are rampant in lawns. While most diseases present in lawns are not fatal to mature turf, to new seedlings, it is almost always fatal.
3) Any grass that does germinate and grow will need to be watered continually to ensure survival. The young root system and crown of the plant is extremely tender and once we reach consistent temps over 80 degrees, turf slows down on growing. New grass does not have a well enough established crown and roots to survive the heat and drought stress we always have during the summer.
4) Aeration in the spring does more damage than good. Aeration works to provide the benefit of loosening the soil, however, the spring usually has saturated ground. An aeration in the spring can cause a muddy mess and create other issues. Additionally, turf does not respond well to a spring aeration due to the biology of the growth cycle. In the spring, turf is focused on shoot growth. When we aerate, it damages and cuts the roots. When we do this in the spring, the roots get cut and the plant is not going to repair them causing additional damage.
Most of the time, a spring seeding is unsuccessful and the lawn will have to be reseeded in late summer/early fall.
The following link is to a publication from Purdue University regarding seeding.
If you were going to consider spring seeding, it would be done by simply broadcasting the seed over the lawn in late winter. The continued freezing and thawing of the soil works the seed to the soil. If that is done, no weed control could be applied for several weeks and no typical crabgrass preemergent can be applied. There are some exceptions to the rule with special order products but in those cases, it sometimes can be cost prohibitive.
Bowman's Pro Turf, LLC. 