All those are good suggestions. If you want to get this back on track, it is a little too late for most of the US to use chemical fertilizers. Now would be a good time to learn more about the modern organic approach to lawn care. You can use a grain type fertilizer any day of the year, in almost any amount, with no fear of hurting anything. The only drawback is it takes 3 weeks to see the improvement. With your lawn the improvement will be as delicate as your supposed stripes you have now. Yes, I do see them, but jeeze Louise, talk about subtle! This is what can happen to your lawn on a super organic regimen - meaning where most lawn nuts would apply 100 pounds of grain fertilizer per 1,000 square feet over the course of an entire season, this guy applied 1,800 pounds during the season. He was looking for the limit where enough is too much, but he never found it. Here's his lawn in July of 2010. Note the subtle difference between his lawn and his neighbor's lawns. The lawn is a mix of elite Kentucky bluegrasses. He was watering deeply once a week, mowing at the highest setting once a week, and fertilizing with 50 pounds per 1,000 of soybean meal and Milorganite ONCE A WEEK. If you want to do that, you're welcome. But all you really need is 20 pounds per 1,000 of alfalfa pellets (rabbit chow) once every other month. But if you want unmistakable results, you can apply more often. The first time you apply it will take 3 full weeks to see the improvement. After that it just remains deep green like that all the time unless you miss a drop. Back to your lawn: In that condition it would be the best lawn on my block. Since you seem to be looking for perfection, let's ask some questions. Where do you live? What kind of grass is that? What is your watering regimen? How often and how much do you apply? How high/low do you mow and how often? How often do you fertilize and what do you use? Otherwise the lawn looks great.

There isn't much you can do about the weeds now except preventing them from setting seed -- so I would keep them mowed low as soon as they start their flowering/seed production in late winter/early Spring (this is as soon as we break from the winter pattern and things warm just a little bit -- as early as late February depending on where you are, elevation, etc.). I would wait until late summer/early fall to try to build the lawn (aside from a pre-emergent for summer annual weeds in Spring). The folks over on the lawn forum know a tremendous amount about how to establish a lawn that will choke out weeds. But, I will say that condition number one is you can't grow dense cool-season turfgrass without at least 5-8 hours of sun per day (and the 5 is pushing it). Good luck!

No that synthetic product will not kill all the earthworms, but the use of it also means that you are no longer an organic grower. If you use that synthetic product exclusively the Soil Food Web will eventually run out of food and either die off or go dormant. The earthworms will leave for a better environment. kimmq is kimmsr

I suggest seeding in late August or early September. Do a soil test now and get recommendations on lime and any other nutrients your soil needs. You can make amendments this spring and summer to help prepare. Lime, if it's still needed, can be applied every 90 days during the growing season. You could work on killing weeds now or wait until July if you want to kill everything for a fall renovation. You may just want to do an overseeding. If you want to work on weeds now, use a pre-emergent when the forsythia blooms. Use an amount that will wear off by the time you want to seed (read the directions). Use a broadleaf weed killer later in the spring when the weeds are actively growing. If you want to work on weeds later, just mow them this spring and then use Roundup to kill everything in July. Water lightly each day to encourage weed seeds to germinate and a few weeks later kill them again. If you don't want to kill everything but just want to overseed, use selective weed killers this spring and summer as needed and pay attention to how long you must wait until you can seed (read the directions). Sow seeds and water lightly and frequently, gradually decreasing frequency and increasing the amount as the grass comes in. As far as fertilizer, you could do an application in late May, then an application at seeding in August/September (starter fertilizer), then another application (normal fertilizer) in October, and a high nitrogen one after the grass stops growing but before the ground freezes (maybe around Thanksgiving). Do not fertilize in early spring. Keep any lime applications two weeks from any fertilizer. Straw would go on top of the seeds when you seed. All this is assuming you have a cool season grass. What kind of seed will you be using? Are you using good lawn practices for mowing and watering? Don't cut off more than 1/3 at a mowing. Water deeply and infrequently. When you seed, do not use a weed and feed fertilizer as it will keep grass seeds from germinating. In general, use weed killers for weeds and plain fertilizer for fertilization instead of a combination product.