Watering Shrubs Daily a Mistake. Why?

Q. I live in a climate very similar to Las Vegas; USDA Zone 8B. I planted a 1-gallon Texas ranger shrub two weeks ago in sandy/stony soil, watered them with about 2 gallons daily for 10 days. After, I put a 1-inch deep, bark mulch on the soil surface. Now, three weeks later, the leaves are yellow, brittle and crunchy on the lower stems with curling leaves on the top. I think I overwatered, but I’m not sure.

Honeysuckle crown or collar rot. A disease of plants that are watered too often.

A. Yes, sounds like they were watered too often and now probably “root dead”. Watering too often has caused the leaves to yellow, brown, and get crunchy. After the initial watering, let the soil drain water and give the plant roots air.

The plant roots drowned because the plant was continuously watered. Watering the plant with 2 gallons is about the right amount after planting. It could even be more than that. But after that, schedule the irrigations to skip at least one day so the water drains from the soil in the roots can “breathe”.

This time of year in early spring, probably once or twice a week watering is enough, even for a sandy/rocky soil! The soil around the roots was amended so it will hold water. The bark mulch on top of the soil gives you about a day extra between irrigations.

The bad news is that the soil surrounding the overwatered dead roots is probably “contaminated” with root disease problems. It could be replaced I suppose but I suggest digging a new hole for planting, at least 2 or 3 feet away from the old, contaminated hole.

Dig the hole 2 to 3 feet in diameter for a 1-gallon plant. It doesn’t have to be deep, but wide. Next, mix the soil taken from the hole with about one third compost. Wait till the last minute and finally remove the plant from the container. To do this, turn the container over and let the plant slide onto your hand. Lower the plant into the hole, holding it by its rootball, and place it so it’s resting at the bottom of the hole.

            As you are pushing this mixed soil back into the planting hole, everything is wet. Make this planting soil a “slurry” by adding water slowly to the whole with a hose so this “slurry” flows and fills all the gaps around the rootball. You should see air bubbles surfacing from this slurry. Build a moat, 2 foot wide, around the plant to force excess water down and not run off the soil surface. Fill this moat with water. Do this twice. No more than twice.

            If the plant came with a nursery stake, push it into the wet, solid soil at the bottom of the hole next to the plant and re-tie the plant to the stake with stretchable, green nursery tape. This immobilizes the plant until the roots have anchored it into the soil. Remove this stake at the end of the growing season.

            If you buy 5-gallon plants, use around five gallons of water when irrigating with the timer. If you buy 15-gallon plants, plan on around 15 gallons of applied water when irrigating. What killed the plants is watering too often, not the amount applied.