Construction and Renovation

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Posts tagged aerate
Rehab for your Lawn

After months of dry weather and in some areas, extreme drought conditions our lawns are showing signs of stress. Some are bouncing back better than others but all are in need of help in some way or another. Many homeowners rely on automatic irrigation and heavy fertilization programs to maintain a lush green lawn. Water restrictions and indefinite water bans made regular lawn maintenance difficult and in some ways detrimental. 

Turf grass is opportunistic. When conditions are right the grass will flourish, usually. When conditions are poor grass will show it's weaknesses and in some cases throw in the towel altogether. 

The key to a consistent lawn is tough love. 

Don't bother trying to repair your lawn during hot summer months. They're known as cool weather grasses for a reason - they thrive in cooler weather. Spring can be a good time to make repairs but the window is often short and unpredictable. Fall is the best time to give your lawn attention. Set it up for success in the fall and send it off on it's own, see how it does and if it needs help, wait until next fall to try something else.

The above picture is what most New England homeowners saw in their yards as the summer came to an end this year. Patchy tufts of green. 

A lawn is typically made up of a variety of grass species. When the lawn is thick, all varieties of grasses are doing well. When the lawn is patchy like the picture, the weaker grasses have gone dormant or died off and left the stronger or more opportunistic grass to thrive. 

First: When the nights have cooled enough that you see substantial dew in the morning, cut the lawn short. You should have been mowing tall all summer, between 3.5 and 4 inches. Now it's time to go down to about 3 inches. 

Cool nights and shorter days lessen the need for irrigation, increasing the success rate for grass seed. Cooler weather also slows the spread of weeds and other warm weather invasives like crabgrass.

Next: Aerate! Deep core aeration. Lot's of holes! Aerate immediately after you mow when the lawn is shortest. Some people like to mow again after aeration to pulverize the plugs. This is a matter of preference. Both have their benefits. 

After aerating, fertilize and seed. The product will make it's way into the holes .

A few days to a week after aerating and seeding you'll see signs of life. The picture above is the same patch of grass in the first picture. Notice the young grass shoots in the middle of the picture. 

Top dress with compost or topsoil after seeding, the same day or up to a few weeks later. The above spreader is used to spread a thin layer of compost over the lawn. The same can be done manually with a shovel, a rake, a strong back and a team of help!

The idea here is to add organic micro nutrients to the top layer of soil which will help retain water, and fertilizers in the seasons to come. It will also help to sow in new grass seed. 

When you're finished your lawn is likely to look like hell. You may wonder why you're doing all of this and how it's going to help. After a few weeks you'll see noticeable improvement in color and thickness. Your lawn will winter better and come back faster in the spring. But the real reason you're doing all of this is to get it through next summer. You want deep healthy roots that will store water between rains and find water during droughts. You want thick grass that will feed itself between fertilizer applications and grass that can stand up to foot traffic and heavy use. Strong grass will resist disease and infestation. Strong grass will require less water and fewer chemicals. Strong grass will cost less.

Although you may spend more time mowing...


This is a rehab, not a regimen. This is something that should be done if your lawn is in decline or showing signs of distress over the long term.

This may be used as a maintenance practice but I don't suggest doing so more often than every four years. 

Do not use herbicides until grass has filled in. Herbicide can negatively affect grass seed and seedlings.

A service like this is likely to cost anywhere from 8 to 12 cents per square foot of lawn.

Next Question - When do I Aerate?

Yesterday's post topic got a lot of great feedback. Thank you for that! It stemmed another question, one I hear discussed often. But since I have your attention I thought I'd follow up with it here.

When do I Aerate? 

The short answer is - Detatch in the spring. Aerate in the fall. 


The long answer is as follows; (see my last blog post on dethatching) Dethatching breaks up the mechanical properties of the plant. Don't think of your lawn as one plant but rather a community of thousands or millions of individual plants. Dethatching your lawn will help individualize the plants as they were last fall before the snow. Perrenial grasses like we have here in NH go dormant over the cold winter months. Once the soil temperatures stay consistently above 60 degrees during the day and 40 degrees at night, grasses will come out of dormancy and actively grow again. So when you're dethatching the lawn, think of the process as breaking the lawn out of it's dormant state. Open up the void space between the plants. That's where they will be taking in what they need to start growing and spreading again to fill out and green up your lawn.

Aerating breaks up the soils and agitates the root structure of the plants. So while I am a huge advocate for aerating, it's a fall chore.

Pictured above; (top) very common walk behind aerator (bottom) plugs removed from lawn by aerator

There are exceptions to the spring/fall rules though. In short the rules don't apply to serious amendments to the lawn and with that consideration, break the rules. For example, last spring my lawn was entering it's second growing season. It was installed with heavy equipment. The top soil I was sold was not the greatest and the first growing season was very dry. The front lawn was hydroseeded and after a bad experience with that, I seeded the back lawn conventionally with better success. The front lawn had a crabgrass infestation before the lawn could establish. I began what I had planned to be a two year process of resurrecting the front lawn. I aerated early in the spring and over seeded immediately. About a month later, once I knew the new seed was strong enough to withstand chemical treatments, I killed the annual. I sprayed a crabgrass killer. I found out just how bad the lawn was because anything that wasn't perennial died and turned brown. I aerated again and mowed the lawn very short. About a month later I treated one last time for crabgrass. By now the new seed from the spring had become grass and green was making it's comeback again. More on this experience in a later post. But my point here is that what I'm telling you isn't rule, any gardening endeavor is an experiment so challenge conventional thought and get creative. I'm doing my best to explain the fundamentals. I know a lot of my readers aren't physically getting out there and running behind the aerator, they simply want to make informed decisions when applying hard earned dollars to their properties. So whether you're the do-it-yourselfer or the inquisitive homeowner thanks for reading, I'll get back to the topic of discussion.

Aerate in early fall. September is ideal.

If you've had foot traffic or a heavy lawn mower running over your lawn all summer it's time to open up the pores and let her breath. I like to plan an aeration a week or two before a fertilizer application. The biggest reason that the spring is not the season to aerate is crabgrass. Crabgrass seed is dormant until soil temps reach the 80s during the day and a chance of frost is gone. So if you, your neighbor or the truck driving by with grass clippings in the bed, have any dormant crabgrass seed blowing around it will have a much easier time germinating in that nice little hole you made for it with your aerator. This goes double for those of you who spread a pre-emergent to keep the crabgrass at bay. The pre-emergent acts as a barrier only allowing the perennial grasses through and once you poke holes in that barrier by aerating, goodbye lawn, hello crabgrass. In the fall crabgrass has gone dormant weeks before perrenial grass says good night. With the crabgrass dormant you'll be safe to poke holes for the health of your perennial grass lawn. 

Spring: Break it up and Rake it up! 

Fall: Open it Up before Closing it Up.

So in the fall plan to aerate, overseed, wait a few weeks, then fertilize and by spring you'll be good to dethatch and spread your crabgrass preventer. Hello Lawn!

What can you expect to pay? If you rent a machine yourself you'll be paying $75 for a weekend that you'll probably feel for the rest of the month. If you have it done by a professional you can expect to pay a range of rates from twice the price of the weekly mow to $100/hour. Aerating is taxing work but requires no real skill so shop at will.

Big things to watch for when aerating: Invisible dog fence, sprinklers, drainage and and other shallow run utilities. So survey your property and mark everything before aerating begins. We run the sprinklers and locate dog fence to thoroughly mark utilities before aerating.