I used some cow manure product on my garden last fall. I also added some garden soil and compost. Now I have a zillion wild onions and that bindweed stuff everywhere I put it.
Any recommendations of soil and manure products that have been found to have few weed seeds in them? I watched a video of a fellow evaluating them but it was mostly about OMNI certification and probably paid for by Walmart. He did not address weed seeds or the lack.
Any observations?

Jane: I am interested in this too. One of the reasons I am trying hard to limit some, my Iris purchased this year( not doing too great) is to have time to build up the soil in some of the beds. I have nil experience at this, as a Gardener.

Cow manure runs about 10-3-6 when composted. It's pretty high in nitrogen, but is very low in Phosphorus and Potassium Oxide (Potash) If you have tested your soil you will get a report on what you need to supplement your soil with. Otherwise, you're just adding stuff, and just guessing what your soil might need to grow what you want to grow. There are other trace minerals that could be lacking as well, as knowing the acid/alkaline properties of the soil. I have really rich black soil here, I had added composted horse manure in the past, but I quit doing that, because my soil is very rich organically, and adding more just seemed to cause extra problems with rot here. Your conditions are different then mine, so you have to adjust what you do based on what you're working with. There just is no one size fits all answer to your questions. Your local county extension office is a great resource to help you get your soil analysed.

As far a weed seeds in the compost you bought, I don't know what to tell you about that. I haven't had that issue to deal with. I'd sure not buy that brand again if I were you. Hope I was at least a bit helpful to you.

Jane, since our soils around this region tend to have a fairly high clay content I've been using bagged compost with a lot of sand and partially decomposed mulch in it with good results. Interestingly, these tend to be the really cheap stuff- sold in 40lb bags with sand added to make it heavier. I avoided those products for years because I felt ripped off by all the sand added, but I've found that irises love it! I haven't had issues with weed seeds in them. I've tried those labeled "compost", "manure", and "top soil" and have found the plain old top soil to be best, and it happens to be the cheapest of them. My happiest modern irises are in areas where I simply applied bagged top soil to the surface and planted the irises directly in that. The airy layer on the surface has apparently prevented rot issues. My soil here is already pretty dark and has a good amount of organic matter. What is your soil like before amending?

I am not sure what my soil is like since there are different areas where I plant my irises. Some near the back is heavy clay and not dark at all. I am planning to plant there but will need to add lots of amendments to it. We took the fence down from where our neighbor had put up an 8 ft. fence so the chain link had to go. Most of the rest of my yard is just normal soil, not really clay but not rich either. I keep adding amendments but this year the weeds were awful. I think it must have been the manure stuff. I will try the topsoil instead of manure compost. I would like the kind with lots of sand because we have had so much rain!! Some soil that I bought that was an off brand had lots of sand which was great.
Thanks for the information.
Tonight is our BGIS meeting and Rich will do a power point presentation of his median photos from the Median Convention in Indiana. This year we will also be having some from Keppel at our private sale so you better rejoin!

Adding sand to clay soil is never a good thing! So do be careful on the amount added to your soil.

Working in organic compost is always the best choice. On the irises, I stay clear from using any manures, but I do add it to the compost mix (if it's well aged) to other parts of the garden. You could/should also consider adding gypsum in your compost mix.

What might happen? DH couldn't find the requested fertilizer (6-10-10) so he bought 16-16-16, and it was very lightly spread around.

Too much nitrogen will give your irises nice lush green growth. The downside is, it could also cause rot.

no rot, hope not!

I have a whole huge bag of gypsum in my garage so I can sure use that in the garden. I understand it is great for drainage. I agree clay and sand may make concrete!
Thanks for the reminder.

My soil has a pretty healthy combination of sand, silt, and clay, so the addition of sand has never been an issue. I think it's more a problem when it's primarily clay with too few of the other sized particles when you get bricks- like exposed subsoil. The area where the soil was turned over when we had septic work done and left clay subsoil on top is a place I don't use sandy stuff, just compost. The top soil I use in other areas is mostly organic materials with sand added, so probably not a high enough percentage of sand to cause problems.

Gypsum is also sold as " Clay breaker ".
It works slowly over time to break the clay.
Applying it to one hill of clay-it softened only about 1 inch depth of clay over the winter. I mixed organic matter into that one inch in the spring. Then repeated the gypsum again every fall, until the hill was converted to decent soil.