I am ambivalent in answering this. I started with an old 18 Ac field of weeds and briars last year. Killed everything with Roundup, then a Remedy like agent for the briars.
For six weeks it looked like a moonscape. Not a blade of grass or anything to be seen.
Drilled in the Cheyenne seed, fertilized and the rains came. But, then so did the weeds and Johnsongrass. It was so wet I couldn't get in the field very well, so the Johnson grass reached 6 ft tall and shaded the seedlings. 50% of the field took the seed, the rest was a loss. I have a friend who planted 40 Ac. last year and got nothing. I think the seed wasn't very good. Despite this, I baled the field once a got 58 rolls and it tested pretty good. The cattle loved it - bermuda plus weeds.
Pennington came down and said they would work with me, so this year I got free seed for about 8 Ac. I still have some weeds, but was able to rid the field of Johnsongrass by wicking last year. I clipped the weeds back, drilled the new seed, and then we had one good rain. I have not fertilized yet, since I didn't want a repeat of last year- stimulating the weeds before the grass germinates and takes off.
I haven't seen a blade of Cheyenne come up yet and it has been in the ground 3 weeks, but admitedly it has been dry and was cool. It is hot now, but still dry. This may be the problem? Time will tell.
My plan is to keep after the weeds, but clipping them just above the height of the one year old Cheyenne. The weeds I have this year are plantain, a good nutritious weed, very few briars, henbit and a few others.
I could not spray again because I needed six weeks from spray to seeding - anything shorter could affect germination. I also couldn't spray due to the proximity of two vineyards that were leafing out - grazon is volatile to some extent. Since I have some Bermuda, I obviously could no longer use Roundup.
If I had it to do over again, I would spray one year and get a good kill. Then I would plant some cover crops. then spray again the following year with Roundup and maybe Grazon and then plant. Two shots at weeds with adequate time for the weed seeds ithat remain n the ground to come up makes more sense to me than what I did last year. I call this field my Bass Boat.
What Cheyenne did take last year, looked good through last season and now. My final verdict is still out, update later.
Billy