Hello Iris,

Mixing microclover into your lawn is a natural way to reduce fertilizer application by as much as one application per season. Clover (typically white clover) has long been used in lawns because of its ability to convert nitrogen gas in our air to the type of nitrogen that grass needs as nutrition in the soil (fixation). https://extension.umd.edu/resource/lawns-and-microclover

Microclovers are smaller varietals of white clover that bloom less than Dutch Clover and have a less invasive, more clumping habitat. Microclovers are mixed into the lawn for this natural nitrogen fixing property to help provide the grass plants with nutrients. Clover does have its limitations. Without irrigation, it will die in the hot dry Michigan summer when cool season grasses go dormant. It also will die back through the winter and needs to be constantly reseeded to continue to be abundant enough to be effective.

The vast majority of lawn grass varieties are more durable and competitive than clover. Grass plants can go dormant in drought and heat as a protection mechanism; clover can tend to die out. Clover also tends to die off considerably through the winter. To keep clover in your lawn, you will likely need to seed in the spring as well as the fall. Also, if you wish to maintain your clover through the hottest part of the summer, you will need to irrigate a couple of times per week.

Also be aware, if you simply overseed your lawn with clover, the clover may grow, but you will likely have clumpy areas of clover within your lawn. The clover will not outcompete your current grass plants. And plan to need to reseed the clover every fall and spring to keep from having bare soil that will quickly get overrun with weeds.

An excellent resource on clover in the lawn is https://extension.illinois.edu/blogs/ilriverhort/2016-03-18-microcloversa-new-lawn-alternative

Now to your question about shade grass. There is no cool season grass variety that will thrive (or even tolerate) dense shade. All grass varieties need SOME sun to grow – even shade tolerant varieties. For dense shade grasses, they still require 2-4 hours of full sun or 5-6 hours of dappled shade each day. Microclovers as well, require 4-6 hours of direct sunlight per day to thrive. If your “shade” area gets less sun than that, you may want to consider opening up the tree canopy in order to establish grass and clover, or plant shade loving ground cover instead of grass. Here are more considerations when growing grass in the shade: https://extension.umd.edu/resource/growing-grass-shade

If you are going to attempt to establish grass in the shade area, your first step should be to have an MSU soil test performed. You will want to understand pH and nutrient needs to give grass plants and clover the best chance at survival. https://homesoiltest.msu.edu/get-started

As far as varieties are concerned, fine and tall fescues are the most shade tolerant grass varieties, but they still require 2-4 hours of direct sun a day. If you are not getting 2-4 hours of sun exposure, you will experience an increase in shade tolerant weeds and moss as the grass plants decline. If you wish to attempt fescue overseeding, try to determine when your dense shade area experiences the most sun (early in the season before trees leaf out, mid summer when the sun is farthest north, etc.) and attempt to seed then. Some people that try to establish grass in dense shade are committed to overseeding multiple times per year (spring and fall), every year, to constantly replace the declining grass plants.