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A builder built a new home for us last year (2013) and put sod in the front, and a seed blanket in the back. The seed blanket came up somewhat patchy, so we bought a few bags of seed and a spreader, to put down some additional seed to help the lawn grow. Also, we don't have a sprinkler system, but I did move a single hose/sprinkler around the yard to help it grow.

Fast forward to Spring 2014: the snow has melted, and the grass is starting to green. The back yard still has lots of patches, and weeds are growing everywhere.

What am I doing wrong? What would be the best way to help thicken the back yard as I would imagine this is the key to a weed free yard. Should I pull weeds manually or use an herbicide? Should I fertilize? Should I aerate early in the year? Should I put down more seed?

Edit: I wanted to include this wonderful article I found online as well: http://www.richsoil.com/lawn-care.jsp (both for my reference as well as for other visitors).

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  • Need a bit of clarification - 'seed blanket' - I'm assuming you mean a pre seeded mesh which is laid down - if so, was the mesh biodegradable, or is it still present? Is there a reason that sod wasn't used in the back? When you reseeded, did you prepare the ground first, or just spread seed around? – Bamboo Apr 28 '14 at 16:03
  • Yes, seeded mesh. I believe biodegradable, but perhaps lower quality since a lot of it is still visible. Sod likely wasn't used in the back due to cost savings from the builder. I didn't do anything to prepare (I'm a new homeowner, likely inexperienced in what should be done) when putting the new seed down. – Kyle Ballard Apr 28 '14 at 17:06
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ground prep is crucial for a new lawn. I assume sod was used in the front for appearance and cost, but the new lawn in the back was a starter blanket for lack of "street view" and return on the cost. Nothing beats sod. Period. I worked installs for landscape construction for nearly 7 years and the ROI on the sod was a bit more upfront for less hassle & chasing seed/weed/feed cycle in the years to come.

Here are some tips to help you out:

  • Prep the PATCHY/SPOTTY areas again. (Not the WHOLE backyard). Rough up the soil where you want the seed to grow better. Give the soil a good scratching and lay down the seed. Make sure the soil has a good nutrient base. Dirt stinks... add compost or loam if you can. Don't over-seed in this step though as it will chock itself out. Do that later once your seeds have started to germinate and the grass-area-to-be is visibly "green" from a distance.
  • Mulch it. We used "Penn Mulch" (most likely available at you local agway/landscape plant supplier... may not be a box store product. Too much penn mulch will also choke out the seed. (there is a fetrilizer component in it as a starter solution) Don't use hay. It's pointless. It makes a mess with the smallest amount of wind and doesn't really provide much of an evaporation barrier.
  • WATER WATER WATER. If you don't germinate the grass won't grow. Make sure you continue to water thoroughly, but not so much you get rivers of water washing away the seed. Get enough to soak the surface and make the ground moist... not wet. And make sure you rotate the sprinklers to other areas as needed.

There have been times where we have made a pre-germination batch of seed and soil. One of the best "patch repair" production steps we did to expedite the process. Depending on how much you need you may be able to do this in a wheelbarrow.

  • Put 1-2 lbs of seed into a 1/2 full wheelbarrow of rich compost.
  • mix the seed into the soil by hand, or with a small trowel.
  • lightly water and keep moist in a shady area.
  • stir every day or so to mix the seed around within the compost.
  • after 5-6 days, add another 1-2 pounds of seed and another 1/4 wheelie of compost.
  • continue watering and stirring maintaining a decent moisture content.
  • when seeds have sprouts 1-2 inches long you can transfer the mix to the pre-scratched patch areas.

Do not "pack" down the soil as it will crush the new seeds. Rather spread it with a spade (shovel) and then use a spring rake to even out the areas. maintain water for the next few weeks until the patch area grows in.

  • By 'good scratching', do you mean till the entire backyard from scratch? I'm just confirming. I may also seek a consultation from an area landscaper. – Kyle Ballard Apr 28 '14 at 17:47
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    not if germination has started. It seems you have visibly patchy areas... use a wire spring rake on those patchy areas. NOT AN IRON BOW RAKE!... too rough on the soil for this job... use one like this: thd.co/1ixCGUL. Scuff up the top soil so the seed will settle into it, and then the light watering will settle the soil down onto it. – Phlume Apr 28 '14 at 18:51
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You need good soil for grass to grow well. Find your local University Cooperative Extension Office and send them a couple of samples from your trouble spots. It will let you know more about your soil's composition, pH and what nutrients you need to add.

Add lime and other fertilizers as they recommend.

Lots of times in new construction they scrape away and remove the good soil before excavating and haul it away. Then they bring some lower quality soil. It's a good bet your soil is lacking in organic matter content. This is very important to help retain moisture, keep the soil from getting compacted and more.

I would get some bulk compost delivered. You'll need about 1 cubic yard per 1,000 square feet. This will spread out to about 1/3" over your entire lawn. Dump it out throughout your yard and spread it around using a rake.

After you've topdressed with compost spread some more seed at the recommended rate for overseeding an existing lawn on the bag but go over the bare areas twice. Go over the seed lightly with a spring tine leaf rake to help get good seed to soil contact. Renting a lawn roller to help press everything down may help but you can do without it.

Watering is very important. If the seed dries, it dies. If you don't keep the seeds moist you will get very poor germination rates. The compost will help retain some of the moisture but you still need to water at least 2x a day but 3 is better. You only need to water enough to keep the top 1/4" of soil damp. Once all your seed has germinated the roots are still small and need water frequently. Cut back your watering to 1x a day for a few days, then every other day for a few days, then every 3 days, etc... until you get to your normal watering schedule.

The compost will help retain water better than your soil but in some of the bare areas you may want to cover the seed with straw (not hay because it contains weed seeds). It will help retain moisture and shield the soil from the sun, preventing it from drying out a little more. The straw breaks down pretty quickly and you won't notice it once your grass has come in.

  • Thank you, I appreciate the time you took to put this all down. Hopefully it helps others in the community as well. – Kyle Ballard Apr 29 '14 at 13:40
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After construction, very little of the original topsoil will be left. Dirt is Dirt. Doesn't matter what kind you have, you do have to know what kind and what proportion (clay, silt, sand...organic matter) you DO have. Soil is basically tiny little rocks and you need to understand what their size means...Then you have to learn to manage whatever you have...right now you probably have a lot of subsoil with no organic matter (but few weed seeds!) Lawns can be grown in poor soils, as long as you know how to improve them over time.

Hopefully, the contractors brought in topsoil with organic matter before they sodded your lawn. The front is what 'sells'...the back, is 'less important'...sigh. Hopefully, the planting beds are mounded higher than the lawn and they installed edges by trenching around the edge of the lawn. Hopefully, if you have automatic irrigation that the two areas (plant beds and lawn) are on different zones.

If not, healthy plants HAVE TO HAVE HEALTHY SOIL. The only way to improve ANY soil type is decomposed organic matter. Bark, wood chips or other non-decomposed organic matter take time and lots of nitrogen to break down where soil organisms are then able to use it for food. Micro and macro-organisms (those you can't see without a hand-lens or microscope (bacteria, nematodes, mychorrhysae...I've got to learn how to spell that word... and those you can see easily such as millipedes, earth worms) need DECOMPOSED organic matter that they ingest, go back down into your soil and poop out the organic debris responsible for water-retention, nutrient retention and aeration necessary for 'good' soil. Try to find a place that 'makes' mulch from human poo and sawdust...and is regularly tested. This stuff is reliable, you know what is in it and what is not in it...no weed seeds, no pesticide residue, a little high in heavy metals from us humans taking prescriptions (so don't use in your vegetable gardens, sigh), beautiful, fine-textured, dark taupe in color. You will notice a marked change in your plants after mulching with 'this stuff'! Careful with fertilizing in conjunction mulching your beds with this stuff...in my area it was called "Gro-Co".

When your lawn is established next year, aerate your lawn pulling plugs and leaving the plugs to disintegrate, dump little piles of decomposed organic mulch all over your lawn, rake into the grass, top seed patchy areas (remember to KEEP MOIST until new grass plants can be mowed). Repeat every other year.

Tilling is not good if you have a high percentage of clay...what is it that makes concrete? Lime, gypsum, clay, gravel, water and mixing. If your plant beds are not done, I would use a spade and fluff up my soil by double digging...once. Soil organisms will do the work of mixing organic matter into your soils. All you have to do is put the 'food' on top of your soil.

For now, using an organic lawn fertilizer with bacteria and michorrhyzae innoculants should produce a very healthy lawn. Organic fertilizers take time versus the POW! you get from inorganic fertilizers. That POW! in my opinion does not make for healthy plants. Once you've begun mowing (about 1 week after sod, 2 weeks after seeding...or allow to wait until the second mowing if too sparse...) water deeply and only when the soil dries out to encourage your grass plants to grow deep roots. Great way to eliminate weeds and shallow rooted weed grasses. Use a line-trimmer to keep the grass from going any farther than the 2-4" trench defining the edge of your lawn.

Test the pH of your soil...lawns need a higher pH in general than most plantings in your beds. Make sure that you get a professional test and add lime if below 6.5. If your soil has a pH of 6.0 for instance, I would do half the recommended amount of lime to raise the pH to 6.5 by the instructions and test again a month or two later. I would then do a second application using what I learned about the results of the first application.

If you have moss, don't sweat it! That is a good indication of where there is too much moisture, no competition or too much shade. Moss is a great opportunist, where there are bare areas and/or too much moisture, a pH that is more acid you will find moss. It is not a serious competitor of grasses. Moss control uses sulfur and causes the pH to lower. Moss won't grow if there are no bare spots, lots of sun and you allow your soil to dry out before the grass needs moisture again.

If you have similar grass mix to those I am familiar in the Pacific Northwest, make sure you don't mow any lower than 3". I've seen the difference between 2", 2 1/2" and 3". Huge. Our grasses in the NW have huge root systems and need photosynthetic top growth to support the roots. Once in balance you have a VIGOROUSLY growing plant that can shade out, out-compete and thrive even when the top few inches of soil are dry.

Make sure your mower blades are SHARP. If not, you will see a dustiness on your very green, healthy grass where there is necrosis from 'ripping' by dull blades.

A simple test I've used to tell if my lawn is dry enough to water, is to step on your grass and the blades don't bounce back leaving a footprint. Use a spade and make sure the water gets down to 4-6"...you want to be able to use 1" per week of water eventually. That is the standard. Depending on your location, humidity, rainfall, type of grasses...this might be entirely different for your needs.

Mowing is important to lush lawns. A minimum of once per week. Twice a week is better. At 3" height the grasses grow at a slower rate, allowing once per week to be enough for that 'just mowed look' and possibly be able to not bag your clippings. The proper organic fertilizer will have bacteria added that are responsible for decomposing thatch! Organic fertilizers don't have to be applied as often and the 'wow' factor is amazing. Amazing deep green healthy grass over a period of weeks. Don't ever do synthetic fertilizers with broad-leaf herbicide, in MY opinion. You shouldn't need any herbicide if you water deeply, infrequently, mow on high and feed your soil. If you do, use spot herbicide. And make sure you use the right fertilizers (definitely organic) for the fall application! Too much nitrogen at this time can cause major problems with fungus...

Lastly, if you have moles, voles, making piles of soil on your lawn...let them be. They eat (mostly) grubs in the soil, aerate and top dress your lawn for free. Just knock the hills down and rake into the soil. Lower your 'expectations' just a bit and you won't need to control everything. Anything that advertises fast results, complete kill...stay away from.

Sorry if TMI! I am working on this problem of mine...grin.

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