KC Gardens

Here’s the dirt on garden soil: You’re probably not spending enough money on it

Add as much organic material to your heavy clay soil as possible to help it return to its native state. Then you’ll have a better chance to grow healthy, lovely plants such as these SunPatiens.
Add as much organic material to your heavy clay soil as possible to help it return to its native state. Then you’ll have a better chance to grow healthy, lovely plants such as these SunPatiens.

Soil. Gardeners talk about it all the time. In Kansas City, these discussions are not generally positive.

It’s no secret our heavy clay soils makes management difficult. Gardening success starts with the soil.

Soil dictates which plants will grow and the level of success and beauty we will achieve. While it is true our native soils are high in clay, it can be said that none of us garden in a truly native soil. Native soils would be those that have never been disturbed. We all garden in soils that have been disturbed, mainly by construction.

When our neighborhoods were built, the native soil was stripped away, sold to another development, or was compacted and covered by even higher clay subsoils. What we’re left with is of very poor quality, and there is no easy or quick fix.

I often ask homeowners what they spend more money on: plants or soil improvements. Hands down the answer is always plants. But the correct answer should be soil improvements.

Poor soil conditions lead to the death of plants, resulting in the repeated purchase of more plants. If garden soil was returned to its native state, then plants would thrive, saving money in the long run.

Good gardening soil is rich in organic matter and has better structure, which overcomes the characteristics of clay. Fixing the soil will seem impossible at first, but even small improvements make a difference.

The goal is to improve the soil’s structure, which is how the clay, silt and sand particles bond together.

Soil is only improved with the addition of organic matter, not by adding sand, gypsum or other hocus-pocus stuff sprayed on the ground. Only organic matter has the chemical and physical properties necessary to create the pore space in the soil structure, allowing it to hold the oxygen needed by the roots and the water to support the plant.

So how much organic material is enough? My answer is as much as you can afford.

It could take as much as four inches of quality organic matter worked into the upper six inches of soil to make a noticeable change. What does four inches look like? Think bagged compost laid end-to-end across the entire garden. One or two bags spread over an area the size of your living room won’t cut it.

I realize that is a lot. And expensive. But it takes a lot to break up our heavy clay.

Adding organic matter can be done anytime the soil is turned. It does not have to be added all at once to the entire garden. Nor is anyone saying you need to remove every plant from the garden.

It’s easier to amend the soil before planting, but when a plant dies just yank it out and work in an ample supply of compost. Over time, patch-by-patch, the garden can be improved.

If your garden is already thriving, you do not need to add additional amendments.

As our gardening blood starts pumping with anticipation of spring, it might be time to stop dreaming of the latest, greatest plants to add. Instead, it might be time to work on our foundation and the basics of plant support.

It’s not glamorous, but just like us, true beauty starts within.

Dennis Patton is a horticulture agent with Kansas State University Research and Extension. Got a question for him or other university extension experts? Email them to garden.help@jocogov.org.

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