Yarb Tales: Wet Soil

The Heritage Herb Garden at the Ozark Folk Center graces the park with visual colors and textures, sweet and pungent aromas. With their natural display, they help us to interpret the history of the human use of plants.

We have enjoyed frequent spring rains this year. The moisture does come with a price. It speeds up plant growth and slows down the progress of wise gardeners. Walking, and especially, the use of heavy equipment in the yard and garden, when the ground is muddy, compacts the soil. Clay particles become elastic and sticky, causing soil to cling to weed roots. Machines operated on wet soil causes deep ruts and hard clods.

Even though the grass grows high and the weeds proliferate during a long, wet season, a prudent person will find more useful things to do than to tromp and ride through the mud. Stay on the path. Spread gravel or mulch on bare ground in foot-traffic areas, sharpen and oil tools, work with potted plants, control disease and insects and sow seeds in flats. Be prepared to mow, weed and plant when the soil has dried out a bit.

Fungal diseases proliferate during cool, wet conditions in the garden. Some fungi spores travel in water and others, on air currents. Human fingers and tools can spread fungal spores from one plant to another when leaves are wet.  With the promise of sunny days in the weather forecast, Heritage Herb Gardeners are going to work on the weeds and the fungus simultaneously.

After a couple of dry days, we will continue to remove weeds and last year’s tree leaves from around our specimen plants. Then we will spread compost on the surface of the soil. To finish, the Mediterranean herbs will be mulched with sand and gravel. Vegetables and annuals will be mulched with wheat straw (not hay) and the more formal gardens will be mulched with a mixture of well-rotted bark and soybean meal.

Compost will boost the levels of organic matter, plant nutrients and microbes in the soil. Admittedly, it will contribute weed seeds as well. It is worth having to return to remove these future volunteers because compost improves the growing conditions for plants.

Applying the appropriate materials for mulch will reduce evaporation of soil moisture, suppress the germination of new weeds and will look very nice. Using sand and gravel around the Mediterranean herbs will reduce future fungal infections by making a barrier between the soil and lower plant leaves. The light color of the mineral-based mulch will reflect light on to the underside of leaves, helping them to dry out quickly. The added light also increases photosynthesis.

Wheat straw (never hay) is good for mulching annual herbs and vegetables; it contains wheat seeds that will germinate and grow more mulch on site, holds moisture in the soil, reduces the germination of unwanted plants and contributes organic matter as it breaks down.

Bark mulch is best used around trees, shrubs and established perennials. Soybean or alfalfa meal is added to bark mulch as a source of nitrogen which will aid in the breakdown of the bark and retain the nitrogen levels in the soil. Using bark in a vegetable garden or around fast growing annuals is not recommended because the bark takes nitrogen from the soil as it breaks down. Nitrogen is the element that plants use for lush, green growth.

Timing and utilizing knowledge is everything in life and in the garden. If I don’t see you in the future—I’ll see you in the pasture!