It's a gamble either way. Soil temps need to be between 50 and 75? degrees for germination. KGB takes 2-4 weeks to germinate and fesucues take about 2 weeks. For Fall seeding: once germinated the plants need time to extablish a root system and store carbs to surve the winter and be healthy. Some people are already seeing a slowing of topgroth.
For Spring seeding you've got the issues of heavy weed conpetition (you can use siduron or tanacity--but it's expensive) and Sring rain washouts.
You could consider dormant seeding but it has many of the same weed issues as Spring seeding except studies have shown better germination rates.

You better check me on whether tenacity is turf seed safe.

Tenacity can be sprayed same day as seeding. Once it germinates,you have to wait 3 mows or about 5 weeks.

Remember with tenacity you need to be very precise when mixing. I think max. Is 16 oz. Total per year.

That's 16 oz. per acre, so if you have 1/4 acre, that's 4 oz. total for your yard for the year divided up any number of ways. Fortunately a little Tenacity goes a long way.

Thank you everyone for your replies! I believe we are going ahead - now that our yard is dirt! We will def look into the tenacity. Love Gardenweb!!! : )

Yes,sorry..".forgot to add per acre.

Way too late for KGB in my opinion, and you're playing the gamble game with Fescue (7 days about to see sprouts). To prevent soil erosion you can put down rye, and then heavily overseed in the spring with KGB/fescue and some pre-emergent protection for the weeds.

I had great luck with the (much cheaper) for application size siduron (Scott's step 1 is what I used), not to mention easier application (spreader instead of sprayer). I tried (unsuccessfully) a KGB lawn 2 years ago and basically had bare ground for 2-3 weeks. NO WEEDS at all with the siduron during that time. That was evidence enough for me that it works quite well at both crabgrass prevention, but also broadleaf weed control (or would at least seem to in my experience due to lack of any weeds popping up).

Tenacity worked fantastic at getting rid of my nimblewill without harming the rest of the lawn, but am not sure if it will prevent crabgrass to the same degree as siduron. And is more expensive than Step 1 (which also had a starter fertilzer which reduced the amount of work when seeding).

I'd go with the siduron for your application purposes, and if needed at a later time, then grab some Tenacity. Oh and do a little dance for a late first hard frost. :)

Siduron (Tupersan is the brand name) only prevents crabgrass, foxtail, and barnyard grass. It doesn't affect nearly as many weeds as Tenacity preemergently, and it is much more ecologically toxic. Using Tupersan for late summer/fall seedings is somewhat of a waste as crabgrass is not germinating at that time and you will have no control of winter annuals like chickweed and poa annua, whereas you will with Tenacity.

Am I inviting a different trouble if I use rye seed?

We live in a heavily deer populated area - right now only the front corner of my yard gets noticed by them - we have managed to remain off of the their regular route...

If the rye comes up am I going to have a heard of deer munching away on my lawn? (as my neighbors often do - anywhere from 8-15 at a time!?)

Thanks again for all of the feedback - you are all great!

tiemco, I don't understand your last post. I understand that a LOT of crabgrass germinates in the spring, but was also under the impression that there is quite a bit of seed from the existing crabgrass (unless very religious on the cutting). We took some long weekends, had some rainy extended portions, and definitely had some crabgrass put up seed stalks. I mulch mow, so I could see how suddenly scalping the lawn, and overseeding could allow for some crabgrass to mature.

Crabgrass is an annual warm season grass. It germinates in spring/summer, grows, puts down seed, then dies off in the fall. The seeds that are laid down won't germinate until next year since they need to be stratified by the winter temps. Those seeds you saw will germinate next year unless you put a preemergent down in the spring. Siduron in the late summer/early fall is wasted since there will be basically no new crabgrass germination. Siduron is very short lasting, it's only good for about a month, so when you use it in the spring it needs monthly reapplications. This is yet another reason why spring seedings are less ideal than late summer/fall seedings. If you seed at that time, you can use Tenacity as your preemergent, then a much better, longer acting preemergent (Dimension, Stonewall, etc.) in the spring.

Deer really don't rely on grasses as a substantial part of their diet. They are more reliant on leaves, nuts, fruits, shoots, and other more nutrient rich plants. I have a herd of deer that are often in the yard, and I have never had damage to the grass due to them eating it (tracks are another story), nor have I ever seen them grazing on it.

Well, not sure anyone will see my follow up but thought I'd let you all know what happened since you were so kind to help out!

Sandy happened.

We never got to seeding because of the storm and of course now we are looking at seeding options for our dirt yard ; )

Someone mentioned to me - December seeding??? and last snow seeding????

oy!

What you are referring to is more commonly called "dormant seeding". Dormant seeding is applying seed when soil and air temps are low enough that germination won't take place. Usually it is done before a big snowfall as the melting action will work the seeds into the soil. If you do dormant seed you want to seed at the higher seeding rates as germination rates are generally a bit reduced. When soil temps rise in spring, the seed you applied will start to germinate, usually without supplemental irrigation, unless it is a very dry spring. When germination does occur you will need to monitor soil moisture levels to ensure your new grass doesn't dry out and die.