Sunflower plot fail?

I planted several plots a month ago - bulk of the plots were sunflower along with a small chufa plot and a medium sized lablab plot. Out of the 3 - I expected the sunflowers to work the best. Boy was I wrong.

Pretty sure the reason why the sunflowers failed was due to the seed depth. I mowed and sprayed the fields with glyphosate. Came back in two weeks later and tilled up the soil with a cultivator and then spreaded nitrogen fertilizer and then ran over with my Plotmaster (disc/seed/drag/cultipack). The Plotmaster was set to dig about 1.5 inches but it was digging in soil that had been tilled 5 inches deep or so.

I checked the plots last weekend (1.5 month since planting) and was shocked how small the plants were

Just for fun and as an experiment... when I was planting I ran my Plotmaster on the opposite side of the road where the sunflower plot was - so no meaningful tillage. Basically one pass that barely scratched the surface. It's crazy how well those sunflowers grew. Especially with no fertilizer. You can barely see in the pic the opposite side of the field where the sunflowers grew up 6 inches compared to the sunflowers in the pic where there was no meaningful tillage. Also, I missed spraying glyphosate in several areas of the field... had great growth in those areas too. Thinking that might be due to the existing weeds/plants preventing me from planting too deep.

Question for yall... I did get growth on the "failed" plot. Just no where near as much as you see where the Plotmaster barely scratched the surface. Can I expect the small sunflowers eventually grow this tall? or have I stunted their growth by planting too deep? Debating on whether I need to replant

In my opinion you planted too late for native sunflowers. I used to grow and sell my native sunflowers for seed. I just plowed in late January and hoped for rains at the right time. If I got the rains I had massive crops...if it did not rain.... No. Call Jay at Turner Seed in Breckenridge......they are experts at this stuff.

Never planted them but it seems like other folks say to plant them around November?

I've tried a couple of times with no real success - I primarily attribute it to lack of rain when needed, but if I recall correctly, the last patch I planted had a maturity of 100 days, so since I wanted the to go to seed in early September, I counted back 100 days to roughly May 20th for having in the ground.

Forgot to mention that I planted Peredovik sunflower seeds - not wildflower.

Still curious if what I have growing (though seemingly stunted) will end up being OK. I am seeing growth, but not quite like the growth in the area I "one pass planted" just for kicks.

Down in South Texas we planted them in early to mid May since our dove season started a bit later. I would think you were a bit early with your planting as it was still very cool in early April even down here. Sunflowers do better than most plants in cooler temps though, just not freezing temps. Biggest problem I when I tried planting them was the deer wiped them out when they got about 18"-24" tall. Never had any survive to make flowers with deer having access to fields. I planted in Hill Country in first week of May and deer wiped them out by mid June. South Texas I planted the in early June with great rain and deer wiped them out by mid July.
Do you think you had a frost on them since you planted a bit early? Any sign of deer eating on them?
Here is a good read on planting them for as an agricultural crop. https://sanangelo.tamu.edu/extension/agronomy/agronomy-publications/sunflower-production-guide/

Thanks for the link stxranchman

Didn't get any frost - I was worried about frost when planting (but had a rare long weekend where I could). Managed to plant shortly after the last freeze and right before the rain started. Checked the weather religiously after I planted. Temps never dipped below freezing but there were some days in the high 30s and low 40s.

I did see some tracks and hog roots in the plot. Nothing too bad though - hogs seem to be focusing on the Chufa plot I planted along with the oats from last year.

There are sunflowers growing but pretty small for being in the soil that long. What surprises me is the wild growth on the narrow strip I planted right along the road across from the field. Been trying to find info on Google about the effects of seed depth on sunflowers and growth, but not finding much info. Hoping what is growing now will ultimately grow into a decent crop. Tempted to spread some more fertilizer to see if that boosts growth any

How is the slope on the land? Could be the right side of the road had more water drain to it and stand for a while. Soaking the ground better in that area. Could it have been a ditch where water stood or drained?

Good point stxranchman. I didn't think about that. The field where I planted was sloped to the middle slightly for what I assume was an effort to promote drain off. Could also just be naturally sloped from years of drainage.

The road does accumulate water. Now I'm wondering if the growth I see in the field is normal for the rain conditions and the growth on the right side of the road is abnormal due to standing water.