Q. In one of your previous articles you mentioned free woodchips. Where do you go to get them? Woodchips are different from bark chips. Bark chips are prettier, but they float and blow away in moderate wind. Woodchips don’t do that. They don’t easily blow away (I have personally seen them withstand 70 mph gusts) or float. Woodchips should be applied at least 2 – 3 inches deep to control weeds and conserve water. Woodchips rot into the soil (where its wet) and improve it by increasing its organic matter content. A. You have to travel to North Las Vegas, but you can get a pick up load or trash bag full from the University Orchard. Call 702-257-5555 and get an update from the Master Gardeners regarding woodchip availability and what days and hours to get them. Woodchips are usually available on Tuesdays, Thursdays and Saturdays in the mornings (except holidays). Woodchips are usually available in North Las Vegas (in the Aliante area) about 100 yards east of North Decatur and Horse Drive at the Center for Urban Water Conservation. Bark chips or bark mulch floats in water and blows in the wind. It resists soil rotting. It is inferior to woodchips (chopped up) from the entire tree.              Woodchips are different from bark chips. Bark chips blow in the wind, resist soil decay and are water proof. Woodchips are made from grinding the entire tree so it can be taken to the dump. Yes, it includes bark woodchips but it is a smaller percentage of the chips and it is mixed together. Woodchips includes ALL of the tree ground up into woodchips, not just the bark.  The weed in the picture is perennial nightshade and, along with bermudagrass, will grow through the woodchip mulch. Why? Because they are perennial and push through two inch mulch. Most weeds controlled by a surface mulch like woodchips are annual weeds. Most first weeds are are annuals.              Bark woodchips are pretty. They make a prettier looking surface mulch. If you want your surface mulch to look pretty, then use a bark mulch. Or use both separated in layers.  Bark chip (bark mulch) doesn’t rot as easily as woodchips because the bark is made to be weather resistant.             Tree woodchips are not as pretty but functional. When laid on top of the soil in a layer at least two inches thick it saves water, controls most weeds and improves the soil. This is what can happen if mulch is not used. Annual and perennial weeds have a field day growing. No competition for sunlight, air and water! Weeds have a field day.             Organics in our desert soil is severely lacking. To rot woodchip mulch takes water. Water and organics in the soil are linked. More water applied, more organics in the soil. Most trees and lawns require at least 2% organics in the soil. Vegetables need more, usually closer to 8% for quality vegetables.  Map of the US soil organic matter content (scientists call it soil carbon content) https://extension.umn.edu/soil-management-and-health/soil-organic-matter-cropping-systems How to judge if your soil has organics in it? Use the color first. If your soil is very low in organics it will be closer to light brown or even tan in color. If organics are present, desert soils become darker and start develop some structure. The higher the ‘organic content” in the soil, the darker its color. If a soil has 2% organics in it, it has a color similar coffee with a creamer in it. If it has 8% organics, it is a “chocolate brown” in color. Mojave desert landscape soil in Las Vegas, Nevada Visually is how to judge if organics should be applied to Mojave desert soils or not. In most Mojave desert soils, we judge a soils “organic content” from its darker color. That’s because it starts off light tan in color. If your soil has a darker color and you can make “dirt bombs”, then adding organics such as woodchips won’t help much when planting trees and shrubs. But that organic content may not be suitable for growing quality vegetables without compost added. A method to use to judge soil organic content is the color of the soil. This is a jar test of a desert soil.