I wouldn't put any kind of Miracle Gro in the soil. Get some soil conditioner, AKA Pine Bark Fines. They should be 1/2" in size or smaller. Mix it with Sphagnum Peat Moss and either coarse Perlite or Vermiculite, and use about two tablespoons of Bone Meal per planting hole.

The mix ratio:

3 parts Pine Bark Fines
1 part Sphagnum Peat Moss
1 part coarse Perlite or Vermiculite

Take that mix, and cut it into your soil at least 50/50, or more until you get the texture you want.

Not only does it make a terrific soil conditioner, but it's an excellent potting mix as well. It drains well, but holds moisture in both the bark and the peat moss. I recycle my potting mix by using it in planting holes all the time, and the grasses love it.

The only ferts my grasses get are a little Bone Meal in the planting soil, and occasional foliar sprays or soil soaks with homemade compost/Eelgrass tea.

Thanks. Glad I asked. I must have misunderstood about the Miscanthus. I had I read it was an exception on the rich soil thing and I was trying to please them.

I've used MG Garden Soil as a soil amendment for planting Miscanthus grasses.

It has worked fine. Read the directions on the bag before starting. One bag should be good for 5 plants.

50/50 amendment/existing clay loam would be ok and the amendment should hold water. I don't add much sand to clay.

I've had good luck planting the grasses at container depth but making the hole 2x the width of the container.

I make sure to water Miscanthus until established. Mine really pop the second year.

True confessions.

I am glad you said that because I did already add some MG soil amendment to three other small miscanthus and was sort of worried and wondering if I ought to go dig it out. After how nice these looked replanted, I had decided to go get the bigger bag and do the other 5 big ones because they are still newly planted enough to dig back up and prepare for summers onslaught and help with watering which otherwise is going to be nearly impossible due to run off.

I add the sand because I found it helps the water drain down faster and deeper to the roots. Otherwise the soil gets so compacted it just won't soak in once summer gets going. Years ago I bought enough peat to cover the state to improve three large areas and it didn't help so much, about 50 of the largest bags. The sand made all the difference.

After I rotted my entire greenhouse one winter after using Miracle-Gro potting soil to repot everything I'm not a big fan of their products.

You can add organic matter to your soil a lot cheaper too.

I'm not buying any. I just used what I had on hand. I've bought some really bad potting soils too in the past. I got some kind that looked like what you rake up in the spring when cleaning leaves. Real coarse and just awful.

I only like peat moss for one thing. Starting seeds. It's naturally sterile, so the new spouts tend not to get fungus and such. For mature plants, I avoid it. The problem I've run into is when it dries, it forms a brick and it's hard to get it to take water.

I've bought potting soil that has peat moss and what happens is the soil dries and contracts along the sides. What happens when I water is the water runs off the top and around the sides of the pot and out the bottom. I end up having to submerge the whole container in water for a minute or so in a bucket to get the peat moss soaked. If I have a small container that I grow seeds in, when I transplant, the peat moss insert goes in the middle of the pot so it any runoff from the tiny insert will stay in the pot.

I ty to buy amendments made from leaves, small sticks, manure etc...

Sphagnum Peat Moss is an essential ingredient in almost all professional quality soil-less potting media. In fact, it's hard to find one without it. I'd bet 90% of all nursery grown plants are grown in media which includes it.

As Wikipedia puts it, Sphagnum Peat Moss is "used as a soil conditioner which increases the soil's capacity to hold water and nutrients by increasing capillary forces and cation exchange capacity (CEC). This is often necessary when dealing with very sandy soil, or plants that need an increased moisture content to flourish."

The CEC is very important. Peat acidifies sweet media (or soil) by taking up Calcium and Magnesium cations and releasing Hydrogen.

Growers use peat moss because it doesn't harbor fungus and bacteria. It keeps the plants alive long enough to sell to someone. The same reason I grow seedlings in it. It's generally not a good thing to add to the soil when planting. In almost every situation, compost is much better.

Sorry, but you're incorrect. Growers use peat moss for the reasons I stated above. It's usually about 15-20% of the mix by volume, and nowhere near enough to prevent or even limit the growth of fungus and bacteria. No growing medium, including peat moss, is sterile once it comes in contact with air, water, fertilizer and plant material.

The choice between peat moss and compost as amendments for soil in a planting hole is one I've never had to make. I use re-cycled potting mix, with peat moss, as a soil amendment, and I use compost as well, if the plant requires the added nutrients. Most ornamental grasses don't require the added nutrients.

By the way, the Miscanthus Grass I planted in the ill-advised and maligned Miracle Grow Garden Amendment is coming along fine and looks great. I had read from the Bluestem Nursery website that Miscanthus is an exception in grasses because does appreciate a richer soil. I followed their advice.

I also put a bit of Nitrogen on my Little Bluestem seedlings this week in the form of a Cottonhull Compost dressing because the Nebraska State Extension says that this is how they do theirs to get better root growth and how they establish their stands of Bluestem for the first two years. They said the Bluestem really appreciate it. They even suggested Miracle Grow Foliar feedings.

This is an interesting discussion on peat moss and soil. I started off a year ago getting back into gardening, etc. and the first thing I did was get my terrible lawn in order (thus the name Grassboro, not for Ornamental grasses). I researched the Garden Web and other good web site forums concerning growing grass, improving soil, organic amendments, etc. with much success. The Soil Food Web, soil test CEC, the Microherd, organics, soil amendments, soil structure, etc. I just put down 50 lbs of Alfalfa pellets on my lawn to feed the Microherd. Grains are great and they really work!

When I started planting a garden I also researched amending the soil in my location. I knew I had acid clay unlike, for example, OK soil which has alkaline clay. I reside in the North Carolina Triassic Basin having veins of red, white, blue, gray and nearly black clay. The Triassic Basin contains mudstones and claystones that are the mainstay of North Carolina�s brick industry.
So for my soil I do not need to add anything that holds water. I already have that. That is part of my problem. I need to improve the oxygen content and drainage of my soil. The North Carolina State University Horticulture Notes clearly state that for our area there are three soil amendments that should always be avoided; peat moss (water retention), gypsum (good for alkaline clay soils, not acid clay soil) and sand (any mixture less than 70% sand in 30% clay actually packs more densely that straight clay, you have brick). If I had sandy soil then peat moss would be great. I also think that for potting soil it is great since a pot of soil is its own soil environment.

All this to say that knowing your own soil and its needs are very important, as I am still learning the hard way sometimes.

Sometimes learning the hard way is the best way since its learning by hands on experience. We have many different kinds of soil here in Oklahoma, it depends on what part of the state you live in and it can vary greatly in a short distance from place to place. Everything I have every heard or read indicates it takes a long time to amend existing soil. Unless you decide to bring in a lot of new good organic soil and create a deep raised situation, you will need to keep improving it year after year by adding some kind of organic compost.

Organic matter is the best ingredient to add to any existing soil in most cases however you choose to do it, slow or spend the money to do it instantly. The best is 50% loam 50% organic. Loam in my understanding, is a combination of sand, silt and clay. These will vary in percentage of which is dominant from place to place. I had clay loam and sand was a good addition for me but also it helped in the kind of plants I was choosing to grow which required very fast drainage, especially in winter.

You might do very well with Panicum grass in some of that water retaining soil. They don't seem to mind having wet feet and grow well here in clay here that doesn't drain well and has standing water at times. There are some very pretty ones.

I chose to quit fighting the situation and let my conditions work for me rather than against me. I am planting Southwestern drought loving plants and grasses that have low nutrient requirements or are indigenous for the most part. It works out well because they are also the plants that appeal to me visually. I am opting for the drought hardy grasses(once established) and I plant the more water demanding ones on the low end of my property. I have a few I plan to remove since they are needing more water than I want to provide year after year. I am done with doing that after fighting it for years and I am also drawn to the environmental benefit of this way of natural gardening.