I can't seem to edit the title. Should read "Dilemma".

If you have enough room, it is possible to make your own compost. That way, you know what ingredients were added, including where they came from. However, it takes time to accomplish this, and I can understand how you would want to get the soil amended and the garden planted this spring. In your situation, if it were me, I would go ahead and use the horse manure compost, and/or the commercial compost made from grass clippings, to amend the garden soil. It is true that there could be herbicide residuals in these products, and it is possible that your garden might not do so well the first year. But these residual herbicides do break down in the soil, and the breakdown process will go faster if the materials are mixed with garden soil, and exposed to sunlight, rainfall, and our atmosphere. You could mix up some garden soil with pure peat moss, and set up some tomato plants in a container of some sort, and in that way you would be certain of getting a few vegetables your first year.

Peat or Coir may be organic matter but they will not provide any nutrients to the soil like compost will. Manure needs the addition of 3 parts vegetative waste for each part of manure whether mixed in the soil or in the compost pile. The poisoning of soils from persistent herbicides is not limited to horse manure or compost made from horse manure but can be in any manure of animals fed the grasses sprayed with them. The only protection you have is to know the source of the manure.

Thank you for the feedback. It seems like there is no way to escape the risk of getting contaminated manure. I had never thought this would be a problem until I ran into some posts here on garden web. Even if I go with bags from a big box store, they probably have the same risk.

I think I will get the manure and till it into half of the garden. That way I have the other half of garden untouched. If it turns out well this year, I will get some more in the fall.

What other options do I have to increase organic matter in the soil? I started using grass clippings from my lawn because I don't spray/fertilize it anymore. I also try to compost kitchen scraps, but that is a very small amount. I am planning on planting couple of comfrey plants.

If you buy bagged compost or garden soil from an established store, and if the bag is labeled Scotts, or a similar large company with a reputation to uphold, then the odds are, there will be no toxic residuals in the mix. The large corporations have laboratories equipped to test raw materials, and they can test finished product, as well. So it is possible to test for herbicide residual in compost or soil, but that technology is not practical for a home gardener to apply. Also, there are chemists working for Scotts who understand that if they allow a load of horse manure to lie fallow for a specified period(24 months?), it will then be safe to use for making compost, as the herbicide residuals will have decomposed. This might be one situation where a trade-name product from a large corporation is above average, and worth the price.

The manure that is sold in the big box stores comes from the large feeding operations known as Confined Animal Feeding Operations (CAFOs) and the slaughter houses where the animals are fed antibacterials to both aid in weight gain and as a disease preventive. These animals are also fed Genetically Engineered grains which are promoted primarily by the parent companies of many of the garden supply houses.
The manure at these CAFOs and slaughter houses is collected as quickly as possible, run through dryers and bagged to be sold as quickly as possible, that manure does not sit around for 2 months let alone 24. These animals most likely will not be fed forage, hay, since that does not promote weight gain as quickly as grains will.
The corporations Eric refers to do not have our health and welfare at the top of their agenda. If what keeps us healthy interferes with profits it does not concern the executives.

Consider a winter cover crop that can add nitrogen and carbon during the season you aren't using it. Your local ag extension office should have suggestions on good plants for your climate. Find out if your town offers free compost or wood chips. The risk of using any outside sources is the chance of introducing pathogens or h/p -cides. Growing your own compost is the best, but it takes time and effort, and one can make mistakes composting the wrong stuff.

My first big compost pile, I included field garlic, thinking; "Oh, the compost heat will kill the bulbs." You guessed it, next year I had field garlic all over my garden. I'd use it, but it's too rank for my DH (gives him gas). Now I carefully dig them out, and trash them, and in three years have seen a big reduction. I hope this helps.

I don't trust Scott's products. If you could raise your own rabbits or chickens you could have chemical free manure. I compost kitchen scraps and we use our grass clippings in our compost pile.

I would go with the horse stable manure. I never have problems with it. It is always good to get manure and compost early and let it completely finish.

I have a small backyard and I am in suburbia, so having chickens probably won't work. I do however compost the kitchen scraps.

I am going to go forward with the horse manure and hopefully everything will be okay. I just can't believe that the chemical companies make us pause when using such a great resource.

I will definitely be planting a winter cover crop. I am thinking mustard because it is an edible green and will be killed off during the winter. Meanwhile however, I will sprinkle fenugreek seeds between my plants. They are very small plants and fix nitrogen.

I am planning on getting wood chips from a local tree service and let them compost in a corner.

Can't wait for Spring!!!

Much of greater Chicago seems to be more progressive on the gardening front then many other areas and keeping chickens (no roosters) is permitted in many of the towns around there.
A simple test to see if the compost might be something you want to use is to germinate some seeds in a sample. If the seeds do germinate and grow and do not die the compost could be some not made with contaminated manure.

It brings back memories of our neighbor bringing us his pony manure. It was loaded with weed seeds.

Leaves of any kind chopped up with your lawnmower is great fall mulch (2-3in.) . Rabbit manure is great to use, If you. don't have enough leaves yourself and you live in suburbia surely you can talk your neighbors out of some. Search locally for someone who raises rabbits , they will generally give you manure . If not offer a few veggies for trade . A couple 5 gallon buckets of rabbit manure broadcast over your garden and tilled in every spring ( if you till) will do wonders . combined with adding the leaves and what little compost you can make yourself,every year will help a lot..

I personally put a scoop of rabbit manure and compost in the hole of every plant I plant . Works wonders !

Good Luck !