Garden soil & the potted plant.

Good garden soil is comprised of 5% organic matter 45% minerals, and the rest is pore spaces for air and water, as shown in the diagram of the previous blog entry.  Garden soil should stay right there...in the garden. Here is why you shouldn't use it in a pot, basket or container. Soil has a complex capillary system that likely goes to China, maintained by earthworms mining the soil and soil dwelling insects. When you remove a shovelful of soil, you disconnect it from it's established capillary system. What you will have in a week or so is a substance that looks like soil, but feels like concrete. Your lovely geraniums will soon be stressed when the 50% of air spaces it needs are non existent. The best thing to use for containers is 'potting soil.' Try to buy a product that is not to light in weight, go for medium weight or blend it with some heavier products. Peat moss is usually a main ingredient in potting soil. Peat moss is an unusual product. It is good at 'holding' water, but once it dries out, it becomes impervious to water, and is difficult to re-wet. Ever watered a container that you knew was dry and the water just ran through? Yep, peat moss. If this occurs you almost need to weigh the container down in a pail of water or a wheelbarrow full of water to force it to soak up water. Strange stuff, so the lesson is:  try not to get a product that is mostly peat, and don't allow the containers to totally dry out. If you can't correct the drying out issue, get a different potting mix and add a few inches to your pots and mix it in. Watering containers, unlike watering garden beds, should be daily if needed. Pots in the shade may only need water once every other day. Unlike garden plants, potted plants cannot stretch their roots to find water, all they get is what you give them.