Start with the soil you actually have
Most of Rockwall sits on Blackland Prairie clay. It holds water like a bowl, drains slowly, and cracks open when it dries. That means two things: water goes in slowly (run a sprinkler too long and it just runs down the curb), and once the ground is wet it stays wet for days. The most common way to lose a plant here is not drought — it is drowning roots in soggy clay in the first month after planting.
The fix for sprinklers is cycle and soak: run each zone for 8–10 minutes, let it soak in for 30–60 minutes, then run it again. Two short cycles put more water in the ground than one long one, with none of it in the gutter.
The Rockwall watering schedule
Rockwall and the neighboring cities on North Texas Municipal Water District water (Heath, Fate, Royse City and others) run a year-round schedule: sprinklers no more than two days a week on your assigned days, and no sprinkler watering between 10 a.m. and 6 p.m. Hand watering and soaker hoses for trees, foundations and new plantings are generally allowed any day — which is exactly what new plants need. Check your assigned days on the City of Rockwall conservation page, and sign up for WaterMyYard, a free Texas A&M service that texts you each week how many minutes to run your system based on the actual weather.
New plants: the first six weeks decide everything
A plant fresh from the nursery only has roots the size of its pot. It cannot reach the water your sprinklers put on the lawn. Water it by hand, at the base, slowly.
- Weeks 1–2: every day it does not rain, enough to soak the root ball (a slow count of 20–30 with a hose on low for a 1-gallon shrub; a full bucket for a 5-gallon).
- Weeks 3–6: every other day, then twice a week.
- After that: once a week through the first summer, more in a heat wave.
Before you water, push a finger into the soil next to the root ball. Wet an inch down? Wait. Dry? Water. Wilting in the afternoon in August is normal for a lot of plants; wilting in the morning means it needs water.
New trees: about 10 gallons per inch, every week
The rule of thumb for a newly planted tree is roughly 10 gallons of water per inch of trunk diameter per week for the first year, split into two or three slow soakings, applied to the root ball itself — not the lawn ten feet away. A 2-inch tree wants about 20 gallons a week. Easiest ways to do it: a hose on a trickle for 20–30 minutes at the trunk, a 5-gallon bucket with a small hole drilled in the bottom, or a slow-release watering bag. Keep a 3-inch mulch ring out to the drip line and keep the mulch off the trunk. Trees planted in October need this through their first summer; trees planted in June need it from day one.
Lawns
Established Bermuda, Zoysia and St. Augustine want about an inch of water a week in summer, less in spring and fall, and very little in winter. Deep and infrequent beats shallow and daily — it pushes roots down where the clay stays moist. Set a few tuna cans on the lawn and run a zone: however long it takes to fill them an inch is your weekly run time (split into two days). Water before sunrise; evening watering on St. Augustine invites brown patch in fall.
Containers and hanging baskets
Pots dry out in a day in July. Water until it runs out the bottom, and in the hottest weeks check them morning and evening. If a pot has dried to the point the soil pulled away from the sides, set it in a tub of water for half an hour so the root ball can rehydrate — pouring water on top just runs down the gap.
Signs you are watering too much
Yellow lower leaves, leaves that drop while still green, a sour smell at the soil, mushrooms, and wilting even though the soil is wet. Overwatered plants and underwatered plants both wilt — the finger test tells them apart. When in doubt in clay, wait a day.
Written by the Nursery Professionals at Landscape Source Nursery, 167 Ole West Lane, Rockwall. Questions? Call (469) 698-0037 or send us a note.