Hello and thank you for contacting Ask Extension. What a great idea to convert farmland/watershed land to native plants. That is such a great idea on so many levels. You are right to start with a soil test. You can check with your local Extension Office (Here is a link to the Saginaw County Extension Office https://www.canr.msu.edu/saginaw/county-extension-office ) to see if they have soil test kits in stock. If not here is a link to order one online. https://homesoiltest.msu.edu/ You also might want to ask your local Extension Office about resources, grants, and help with your project.

You are also correct in wanting to get rid of invasive species before you get started. If you have autumn olive, they can be tough to eliminate. Fall is a good time to start this process. One way is to cut off the top portion of the plant and then treat the remaining stem with a product containing glyphosate. In the fall, the plant is naturally taking liquids down to the roots and the glyphosate will kill the roots, hopefully getting rid of the plant without additional treatment. When using herbicides, be sure to read and follow all instructions on the label. The label is the law. You also want to be careful not to harm non-target species. You also might want to check and see if any permits are required before using an herbicide, especially since you are in a watershed area. Here is a link to a good article about autumn olive https://mnfi.anr.msu.edu/invasive-species/AutumnOliveBCP.pdf

Your local conservation district may also be able to help you with your invasive species eradication project. They also may have someone available to come out and help you with your project. They might also know of grants that are available and/or have seeds to help you get started. Here is a link to their website: https://www.saginawcd.com/ It looks like they have a Habitat Restoration & Enhancement service for Saginaw County. https://www.saginawcd.com/wildlife

If you decide to tackle this on your own, I’d treat it as a multi-year establishment project rather than a one-season planting, because establishment is the most important phase, native species are slow to establish, compete poorly with weeds early on, and may take up to four years to become fully established.

A good step-by-step approach is:

1. Map the site before you buy seed.
   I found that using a soils map, such as the NRCS Web Soil Survey (Web Soil Survey - Home ), helps you decide which parts of the field are best suited to different native species or mixes.
2. Choose plants for your local conditions.
   Use native seed and cultivars adapted to your region and site conditions, and consider including both grasses and flowers and maybe some trees and shrubs, since mixed plantings can improve establishment success and wildlife habitat value.
3. Do thorough site preparation.
   Existing vegetation should be removed as completely as possible before planting; one approach is using a nonselective herbicide such as glyphosate. Make sure you read and follow all instructions on the label.

Good article for prairie restoration. Prairie Restoration - Habitat Headquarters | Natural Resources

This article explains in detail how to start a prairie garden. Planting and maintaining a prairie garden | UMN Extension

If you have some low areas on your property, you may want to consider a rain garden. Here are some great resources.

Rain gardens part 2 – rain garden plants - MSU Extension

Soak up the rain with a rain garden - Gardening in Michigan

Smart Shorelands: Soak Up the Rain with a Smart Rain Garden - Gardening in Michigan

Eight simple steps to creating rain gardens - MSU Extension

Landscape plantings for wet areas and creating rain gardens seminar - Gardening in Michigan

https://www.michiganmastergardener.org/nurseries-featuring-native-plants

Here is a link to a directory that Michigan State University put together to help people find native plant seed. Michigan native plant and seed producers directory - Beekeeping & Pollinators

Local Suppliers of Native Seed and Plants in the Central Lower Peninsula of Michigan

• Designs By Nature, LLC - Laingsburg, MI
• East Michigan Native Plants, LLC - Durand, MI
• Go Grow Plant Natives, LLC - Charlotte, MI
• Michigan Wildflower Farm - Portland, MI
• Wildtype Native Plant Nursery - Mason, MI
• Bendy Stem Farm - Dimondale, MI

Hope this helps. If you have any more questions, please feel free to ask.