I bought a new home last year with my first yard and due to lack of knowledge used Scotts Lawn Care Services (which seems to not have done much of anything - still have bare spots and weeds). I have a two year old son and after reading about chemicals I decided to go Organic. This site is great, I am looking forward to beginning this year (I'm by Philadelphia, PA) without chemicals.
I have two questions, one has anyone heard of HappyLawn services? They claim to use fully organic products, however, there is a pre-emerigent crapgrass product and a weed herbicide - hard to believe that there are no chemicals in those.
Secondly, I have read that Corn Gluten is a good Weed Killer, has anyone used this? Please forgive me if this has been posted before.
The corn gluten stuff release a plant hormone that convinces weed seeds to not germinate. So you still have all the weeds that were already there. And it doesn't make the seeds never germinate, it just makes them wait a while. If you keep forking over money to the company, and taking the time to apply their stuff, you will continue to keep most of the weed seeds from germinating. And they might eventually rot and never germinate. But once you stop putting this stuff on your lawn, you might have a lot of weeds germinating all at once.
For me, I prefer to let the seeds germinate and then the seedling die from a lack of sun due to my tall, thick turf. Or let the seedlings dies from my infrequent watering.
As far as the bare spots go. I'd suggest over seeding with a grass mixture called Penn State mix. It's a mix of a perennial rye grass, a fescue and some Kentucky blue grass. I don't know how large your lawn is but, generally, I'd suggest hand sowing the seed. I apply it thicker than most do. As you sow (throw) the seed you can see the ryegrass seed on the bare spots. So you get a good idea of how well you're applying the seed. I'd suggest you cover the whole lawn with seed, but apply a lot more to bare spots than to areas with grass growing. However where you have a good growth of grass don't waste seed. I don't recommend buying grass seed at a big box store or any national company. You want seed that'll grow in your area. A grass mix that'll grow any where from Maine to Hawaii and Arizona will contain too much seed not appropriate for your area, so winds being very expensive.
I'd cover this with a layer of mushroom manure which you can get at bulk suppliers. You can also get it at nurseries but they usually charge more. Delivery is available or you can rent a pickup truck. The rental is probably cheaper for 2 cu yards and you can get it closer to where you need it. Delivery drivers won't usually go off a paved driveway. I paid $35 a cu yard and $35 for delivery the last time I had 3 yards delivered. I'd try to cover the seed with about an inch of the mushroom manure. From my experience the grass will sprout if covered with even two inches of this compost. If you leave a 3 inch clump in the lawn the seed under it won't sprout till you break the clump up. If you spread this product while fairly dry it'll spread much easier. I spread the mushroom manure by lightly shaking the shovel on the axis of the handle. If you use a fork you'll get unpredictable results.
After the seed sprouts, a week for the ryegrass and 3 weeks for the bluegrass and fescue you can see weeds popping up. I'd suggest you pull any light green grass that grows very fast. We call it quack grass here. It's very easy to pull when young and impossible to pull later. Since it's a grass weed killers won't kill it. So it'd be a good idea to pull it young. From my experience there's never very many to pull but it then gets very thick and over takes if left in the lawn. If you get someone to do the work for you they very likely won't pluck out the quack grass for you so you'll wind up doing this part either way.
Some say you get lots of weeds using mushroom manure. My opinion is that it makes the weed seeds you have grow well. This product is what's left after two crops of mushrooms were grown in manure. It was composted and steamed at least twice. Either the composting or the steaming will kill many or most of the weed seeds in it. There's a Midnight Mushroom plant south of Philly so I'm fairly certain you can find this product in your area.
If they're predicting storms I'd hold off doing this project. If they're predicting light rain for a number of days that'd be good news. If you have a pile of mushroom manure cover it so it stays dry and doesn't wash away. From my experience in Pennsylvania if you don't water this daily it'll still sprout. If you do water you might get slightly better results, but just mist lightly don't pour on the water. I would water this after you've finished to wet the seed and the mushroom manure. Once the manure is wet it doesn't dry out easily. Any left over mushroom manure is excellent spread in your beds.