Dirty Talk

Let’s talk about dirt. We could use the word soil, which would include soil mixes as well as dirt. The first fact that we deal with is that the more dense the soil the more energy required for the roots to move through it. I will use the growing mix we use at the tree farm as an example. The potting soil is pure pine bark of varying sizes. The reason we use it is because it’s light with a lot of airspace. If we use even 5% sand it doubles the weight of the soil and thereby the bulk density. I’m not sure it doubles the energy needed by the root to penetrate the soil but it definitely increases it significantly. We want all the roots we can get as quickly as possible to provide maximum amount of moisture and nutrients available for the tree or plant to thrive. If you notice most bedding plants are grown in a peat moss blend that is very light. Bedding plants are quick turn crops so being able to root in 5-6 weeks instead of 8 is a key for greenhouse plant producers. Now one of the considerations is that the lighter the soil the less the soil is able to store water. So when using a light soil mix you have to be alert and apply moisture as needed.

In the landscape soil tilth can make a difference in how quickly plants grow roots and thereby establish themselves. In general the smaller the plant the more important the tilth of the soil. If your planting 4”, 1 gallon and other small pots the plants ability to quickly grow roots is very important because of the limited roots in a small pot. When you’re planting larger sizes they will have a larger root system and therefore it’s not as critical. The recommendations for smaller pots is to add compost, manure, ground bark and other organic materials on top of the soil then spade, hoe or till in. This creates a loose friable planting area where roots can expand rapidly. When planting larger size material apply the organic material then you can mix it in as the material is being planted, the tilth is not as important. Be sure there is nitrogen as well as other needed macro and micronutrients to decompose organic material as well as extra nutrients for your plants. I would always suggest “MicroLife” organic nutrients to all planting areas. It adds so many microorganisms that will grow and expand over time that bring the soil to life. It’s like a probiotic for the soil. Ok let’s go out get “dirty” and help our plants thrive.