I reseeded my small back lawn last fall with KBG (Midnight/Moonlight) Chewings fescue and hard fescue. I got a late start but most came in well. It's early Feb. and I have a few issues.

1) It's been a wet, for San Jose anyway, winter and I have some rust.

2) I have some sorrel and hairy bittercress that I'm trying to get rid of.

3) Some spots are thin and need more seed.

4) I've got quite a bit of poa.

I'm trying to decide what I should tackle in the spring and what can wait. My thinking right now is this:

Use a fungicide to get rid of the rust, spot treat the sorrel and bittercress with a selective herbicide ( I've used Monterey Garden Spurge Power and it really does the job on both without damage to the lawn) Spot treat the poa with Round-up, overseed the whole lawn to get better established turf.

I know fall is best for seeding, but I'm worried about getting more poa. As I understand it the only hope of controlling poa is by using a well timed fall application of pre-emergent herbicide, and if I use that I can't reseed in the fall.

Any comments or suggestions on a course of action? This is the first time I've done this so I'm learning as I go.

I'd rather not use all the chemicals, but I don't see alternatives until I get the lawn established.

I also did the same to the front, though it didn't take nearly as well and has substantially more problems.

I you want to spray a broadleaf selective herbicide, go for it. Spot spray with Weed-B-Gone. If that doesn't work, spot spray with Brush-B-Gone.

Pull the poa as soon as you see it. Once your KBG fills in, the poa should be kept out simply by the density of the tall KBG.

If you reseed in the spring, then you will absolutely certainly sprout all the weed seeds currently in the soil. Why? Because in order to sprout the grass seed you have to water the lawn 3x per day for 2 weeks. That is perfect conditions to sprout weed seeds. Then your poa problems will turn into crabgrass problems for the rest of the summer. The second problem with planting new seed in the spring is the immature roots will not be able to withstand the summer heat. They will die in July and the crabgrass will take over. That's why fall is the best time to seed.

Don't fertilize until about Memorial Day. Your soil has been building up nutrients over the winter and will release them all at once when the soil temps rise. Ranchers call it the spring flush (of growth). Quite often they cannot keep up with it with their cattle. If you fertilize before the growth flush, you will be mowing every other day. Then after the flush of growth subsides (usually in late April to May), you can fertilize. Fall is the best time to fertilize, so don't try to do your full year's worth of fertilizer in the spring.

In spring, rust is nothing to really worry about.
Come warmer and drier conditions, along with nitrogen, the grass grows out of its rust.

>"As I understand it the only hope of controlling poa is by using a well timed fall application of pre-emergent herbicide, and if I use that I can't reseed in the fall."

You have the concept(s) but have to bring them together.
1.) Poa Annua germinates once soil temperatures rise above 55 degrees
2.) Pendimethalin (Halts) has a 90 day residual
3.) Dithiopyr (Dimension) has a 120 day residual
4.) Prodiamine (Barricade) can last a real long time!!
5.) Turf grass germinates best when soil temperatures are between 70 and 55 degrees.

Now you being in Calf., your temps may be or soon will be approaching 55 degrees, when poa annua germinates. Dropping your preM is the first order of business.

Second point - being in Calf, your time to seed in fall might very well be October, when soil temps begin to fall and are in the 70 to 55 degree range.

February/March to October is a long time - long enough not to worry about the residual of Pendimethalin or Dithiopyr.

>"I'd rather not use all the chemicals, but I don't see alternatives until I get the lawn established. "

I agree. Prevent with a preM. Spot treat as needed afterwards. Feed and water properly throughout the spring and summer, which will promote healthy and thick turf as the Kentucky Bluegrass spreads and fills in. Re-evaluate in September / drop additional seed if necessary. If seed is NOT necessary, drop additional preM becausse conditions also favor poa germination again.

Once mature, established, thick and filled in, your lawn will naturally prevent invasions from grassy and broadleaf weeds. FWIW - Maturity is 3 years.