What to do the Day After it Rains

Look for Borers

 It rained most of the day last Saturday in Las Vegas. The following Sunday would have been an excellent time to look for borers in the trunk and limbs of in landscape plants. Their presence would be announced by sap oozing from these infested, but water-softened, locations even though no visual damage is apparent. If you see sap oozing from landscape plants and fruit trees, it’s a good time to dig into those areas with a sanitized knife to see if you can find this critter and remove it. This will prevent it’s continued damage this spring and summer.  Otherwise you might find a dead limb or two or worse in July or August.

Sap will ooze from borer infested trees and its gooey

Mushrooms are Normal

            After a rain mushrooms appear in a few days wherever wood is rotting on the surface of the soil or underneath it. You’ll see them popping up through woodchip mulch and where dead roots of trees might have rotted. Water helps dead wood rot and disintegrate into the soil where the mushroom mycelia grow. This rotting adds organic matter to the soil, encouraging roots to grow and causing it to become dark brown and rich.

            Just like desert wildflowers, mushrooms pop up quickly to spread their “seed” everywhere in a couple of days after a rain. These mushrooms stay fresh only a couple of days before they mature and die. Sometimes “mushrooms” form beneath the soil, like huge fleshy alien balls, and then pop open at the surface releasing their spores. As soon as you see these mushrooms, knock them over with a rake or smash them with your foot. Pet dogs have reported to become sick if they eat them.

A little bit hard to see but these mushrooms popped up everywhere in the woodchip mulch. Mostly stems left now. The caps are nearly gone.

Underground mushrooms like this one can pop up from the ground after a rain.

When dug up these fleshy underground mushrooms may look like this.

Irrigate Away from Cement

            Rain changes everything in the desert. Desert soils are dry soils and not meant to be constantly wet. When desert soils become wet I think of them as “unstable”, both structurally and chemically. An infrequent desert rain is not a problem. But when irrigation water is applied over and over to a soil that is normally dry, these soils shift, collapse and chemically change. In urban landscapes this can be potentially destructive.

            This is the reason for keeping irrigation water 3 feet away from the foundation of a home, patio, driveway, wall or sidewalk. Corrosive salts are in the soils and irrigation water. These corrosive salts will “eat away” at cement and steel. Salts in the soil dissolve when water is present causing the soil to collapse over time. Water dissolves these salts and carry it as far as it reaches and then deposit it in straight lines or circles. When the same amount of water is applied over and over, the salts are deposited to the same spot each time. These are the white rings and lines you see on cement and block walls.

Salt in the water or soil or fertilizers can eat away at concrete, even the so-called resistant Type 2 and Type 5 Modified

Dissolved salts can creep up walls from being continuously wet. Eventually they will eat away at the blocks and mortar joints.