Question
I live in New Hampshire, and we are working on a large meadow area where we took down trees some years ago.  We have improved the drainage, and we have tried reseeding, but there is still a large area with crabgrass and weeds.  I'm told that  one should not use weedkiller on crabgrass the year you plan to reseed, but we have so much crabgrass (and nettles, and other weeds) that I fear it will just reappear in the new lawn next spring. Our soil is very clay-like, and we plan to put several inches of topsoil down before reseeding, but we also have some areas where new grass is coming in from a recent reseeding.  I fear the raking and topsoil we need will kill that new grass.  Can you suggest how to proceed this fall to get good grass in the spring?

Answer
First, the most important thing you can do at this time is to keep ALL Weeds from flowering and setting seed.  The last thing you need is to deal with Annuals this year AGAIN next year.  And those seeds are a headache you do not want to have.  The WORST thing about Crabgrass is the way it re-grows itself all over the place.

There are two kinds of Crabgrass in this country: 'Big Crabgrass' (Digitaria sanguinalis) and 'Little Crabgrass' (Digitaria ischaemum).  One single Big Crabgrass plant will produce 150,000 seeds before the end of the season.  Many of them will be dormant and viable for several years.

That means you simply cannot control Crabgrass in a single growing season.  You can, however, make progress.

A good Weed management program focuses on PREVENTING more seeds AND keeping the seeds already down there from germinating.

Many people will tell you to put down 'pre-emergents'.  But you need a pre-emergent that will not wipe out microbes in your Soil that keep your Grass healthy and thriving.  Corn Gluten Meal is just what the doctor ordered.  It has to be put down next spring, RIGHT ON SCHEDULE, the week that Forsythias are preparing to bloom in your area.

The best thing about this is that after you put down CGM, you won't have to worry about fertilizing for the rest of the season.  Because the CGM will decompose into slow-release, all natural Nitrogen all summer long.

Have you had your soil tested yet?  Because it is a critical piece of information that you NEED.  Contact your local New Hampshire Cooperative Extension Service for a detailed analysis of your soil:

http://extension.unh.edu/Agric/AGPDTS/SoilTest.htm

Be VERY serious about following their instructions so that you can give them a valid sample.  For the Rolls-Royce of testing, follow the directions at the Soil Foodweb:

http://www.soilfoodwebnewyork.com/

It costs tons of money, and it's worth its weight in gold.

Soil testing will save you money, by the way.  You won't have to pay for anything you already have in your Soil.

At some point, if you can find some ORGANIC compost, or if necessary if you can obtain some top dressing from Home Depot that says 'Compost' or 'Humus' on it, rake a little of that around your lawn.  It will take the Earthworms about 2 weeks to get that underground.

How's your Compost Pile?  Do you have one?  I would expect everyone in the Live Free Or Die state would be doing this in their back yard -- recycling Vegetables, Grass, Eggs, Orange Juice you didn't finish this morning, the leftover black Coffee, Dead Leaves, etc. Garbage in, Compost out.

Seed in the Fall after you are sufficiently up close and personal with your Soil.  You can pick out some outstanding Seed -- stuff that is aggressive and state of the art to work best in the conditions you have.  You can't grow first rate Grass without two things:  First Rate Soil and First Rate Seed.

If you're thinking of incorporating (or wish you could) SAND into your Clay Soil to lighten it, DON'T.  Sand will turn your Clay into dirt so tough you can drive trucks over it, especially if you incorporate while it's raining.  The water plus the Sand and Clay create a chemical reaction that really does transform the mixture into rock solid surfacing.  You need that like a hole in the head at this point.

This is the best way to begin with this project.  Sorry for the long answer -- I do get carried away sometimes.  Whatever you do, do not start broadcasting anything that comes in a bag with Skull and Bones decorations on the container.  You have some incredible flora and fauna underground that will help you grow amazing Grass, but you have to work with it.  Not wipe it out.  Besides, those chemicals are bad for your Birds, your Earthworms, your Butterflies and you!

Let me know when you're ready for the next step.  Thanks for writing.  Beautiful countryside you live in.   Seems like every plot has multiple acres and views of mountain lakes and streams.   I envy you.