Wood Mulches for Desert Soils are Remarkable

Desert soil typical of the Las Vegas valley with caliche

If you don't think wood mulch is important for tree growth in desert soils then you need to study this picture of fruit trees in their second year of growth. These are bareroot fruit trees, supplied all the same size, from Dave Wilson Nursery. Fruit and nut trees include plum, pluot, almond, peach and apple. All planted in the same manner in a typical desert soil in Las Vegas. The only difference was the application of wood mulch to the surface of the soil at the time of planting. Not bark mulch, wood mulch that was diverted from landfills and used as a mulch instead and supplied by a tree service company, First Choice Tree Service.

This is their second year of growth. The soil is classified as a sandy loam but hard as concrete because it lacked soil organic matter. The pH of the soil was right around 8. The salinity of the soil was over 40 mmhos or dS/m. Boron levels varied but about 8 ppm on an average. This soil was about as bad as any soil can get and still grow something. This is very typical of raw desert soils in the Las Vegas Valley.

Wood mulch in the orchard and improved soils

How it was done

Irrigation was installed using 2 gpm bubblers. Irrigation was bubbler and basin, with a six foot basin surrounding each tree. Holes were dug with picks and shovels four feet in diameter and deep enough only to accomodate the roots of the bareroot trees at planting time. All rocks larger than a baseball were removed and the soil taken from the hole was amended with an equal amount of dairy compost. Before planting all holes were leached to remove some salts with about 20 inches of water applied to each basin.

Trees were planted in late January into the basins and watered in as they were backfilled with amended soil. A starter fertilizer, about three pounds of 16-20-0, was mixed with the backfill at the time of planting. All trees were watered thoroughly as they were being planted to remove air pockets. Trees were staked and rabbit protection was provided to the trunks as either paper guards or wire screening. A basin was constructed around each tree and included the 2 gpm bubbler. Basins were about four feet wide.

Soil under mulch after three years of tree growth and irrigations

Finally a coarse wood mulch, coming from freshly chipped landscape trees in the valley, was applied to a depth of four inches in the basin of half of the trees. Orchard aisles were also covered in wood mulch between trees that were mulched. The trees grew for one complete season with and without wood mulch. This picture was taken two months into the growing season of the second year.

The Birdsnest Mushrooms in Your Mulch - Kids Will Love Them!

Reader's "pods found in the garden. All of these might nearly
fit on a quarter to give you a rough idea of their size.

Q. I figured I can't let more than three months go by without pestering you with a question! Attached are two photos of some mystery pods I found in the garden when doing some clean up. One is with the pods closed, and the second is with them open and with what appears to be small black seeds. Any idea what this is?

 

A. These are not pods at all but what is called birds nest mushrooms. These do look like tiny little pods with black seed like things inside them. Like other mushrooms or saprophytic (feed off of dead things) fungi they “feed” of off decaying organic matter in the soil. We can see these fairly commonly in compost heaps, decaying mulches or other places where organic waste is decomposing. They are interesting and kids love these little things.

Unopened or just opening "pods" of the reader

            Nothing to worry about. They feed off of DEAD plants so no harm to living plants or you. They are decomposers so they help to break down litter on or in the soil after or during a warm wet period. I attached a fact sheet from Texas A and M on this interesting form of plant life. I will post your pictures on my blog for others to see them.

 

Birdsnest and other inhabitants of wood chips and compost