Our little corner of the state has a wide range of soil types. From the sand dunes of the lakeshore areas to the hard clay of central Porter County , we can swing from one end of the soil spectrum to another in a very short distance.
Urban and suburban soils take a beating over the years. Often what is replaced after a house is built is actually subsoil that has very little nutrient content. These soils require a lot of supplementing to achieve even marginal growth results. What most of our neighborhood soils lack is organic matter.
Undisturbed soils in the woods have a top layer of leaves and twigs that are constantly being decomposed by beneficial fungus and bacteria. This composting process aids in continually replenishing the nutrients that the forest growth uses. It also helps regulate soil temperature and hold in much needed moisture. Organic matter in the soil keeps the soil loose or permeable. This allows for excellent oxygen and water penetration, which is ideal for root development.
Many years ago when I was in high school my father decided to build a nice big shed. To save some money, he decided that I would dig the footings for the concrete slab by hand. The location he wanted to put the shed overlapped the area where our dog had his nice mulch covered area to run around.
Being the energetic teenager that I was, I went to town digging our foundation. First, I raked out the mulch that overlapped the foundation and started digging there. The dirt there was so soft and dark black from years of mulch cover. The digging was going so fast, I thought I would be done in an hour and a half; but then I got to the ground that wasn't covered with mulch. My rapid progress came to a screeching halt. That section of ground might as well have been concrete. The final 20% of the digging took four times longer than the first 80%. At an early age, I learned a valuable soil lesson.
Tree roots have the same problem in hard, compacted soils. Slower root penetration into new soil means slower growth rates and reduced plant vigor. This doesn't even take into account poor nutrient content.
Sandy soils have a hard time holding moisture. Blending good topsoil, compost, or peat moss can help. Clay soils have the opposite problem. They easily compact, which forces oxygen out and prevents moisture from getting in. Once again, peat moss, compost and topsoil will help. If you have had repeated growing problems in the same area of your yard, you may want to consider a soil Ph test.
The beneficial funguses and bacteria that are missing in urban soil can now be put back into the soil through a soil inoculation by injection or by a soil drench. Mycorhizzae fungus and Rhizosphere bacteria attach to roots and act as collectors of nutrients for trees. They also breakdown what would normally be insoluble forms of nutrients for the tree roots. I would highly recommend this treatment if you have any tree or plant health problems. These treatments are not chemical fertilizers and are very safe since it's all organic.
As I repeat often, seek professional help or advice early to avoid permanent regret.