Water: Deep, Early and Right at the Roots

Why it matters

Running short on water during the first weeks after planting or while fruit is forming cuts yield harder than at any other time. Watering deeply at the roots, plus mulch, gets more vegetables from fewer gallons. Texas law protects your right to catch rain, and rain-catching gear is free of state sales tax.

Step by step

1. Aim for about an inch a week AgriLife's rule of thumb is about 1 inch of water a week from rain plus irrigation. Plan for more as plants grow and summer heats up: roughly 1/2 inch in May and 1 inch or more in July.
2. Soak deep, then wait Water until the soil is wet about 6 inches down, then water again only when the top inch is dry. Usually 1 to 2 inches a week is enough.
3. Check before you water Push a finger into the soil. If it's dry at 1 inch, water. Squeeze a handful: if it holds together in a ball, it has enough moisture.
4. Water in the morning Early-morning watering lowers the chance of leaf disease. Aim water at the base of plants, not the leaves.
5. Go drip or soaker With drip irrigation, about 90% of the water reaches the plant, compared with 40-60% for surface watering. That means about half the water for similar yields.
6. Try ollas in small beds Bury an unglazed clay pot up to its neck, keep it full, and water seeps out to nearby roots. New transplants still need extra water for about a month until their roots reach the pot.
7. Catch the rain Each inch of rain on a roof yields about 0.5 gallon per square foot. A 2,000 sq ft roof gives about 1,000 gallons per inch of rain.
8. Mulch 4 inches deep A 4-inch layer of settled organic mulch slows evaporation and blocks most weed seedlings. AgriLife says a well-mulched garden can yield 50% more.

Key facts

• Rule of thumb: about 1 inch of water per week (AgriLife, Masabni).
• Soak to about 6 inches deep. Water only when the top inch of soil is dry (AgriLife fall guide).
• Drip: about 90% of water used by plants. Surface irrigation: 40-60%.
• 1 inch of water on 1 acre = 27,154 gallons (AgriLife EHT-024).
• Water needs peak at midseason. Tomatoes and peppers use about 15% more than reference evapotranspiration (ET) at peak (crop coefficient 1.15).
• Rain harvest: about 0.5 gallon per sq ft of roof per inch of rain (TWDB).
• Austin's roughly 32 inches of yearly rain could yield about 32,000 gallons from a 2,000 sq ft roof (TWDB).
• Rainwater has zero hardness, is sodium free and has near-neutral pH (TWDB).
• Ollas may save 60-70% of water compared with a watering can. They wet soil out to about 2 times the pot's diameter (University of Arizona).
• A 4-inch mulch layer can mean up to 50% more vegetables (AgriLife E-512).

Texas notes

• Rainwater harvesting is legal and encouraged in Texas. A city or county cannot deny a building permit just because a building will harvest rainwater, though it may require state minimum standards (TWDB).
• Sales tax: Texas Tax Code 151.355 exempts rainwater harvesting equipment and supplies from state sales tax. Give the seller a Texas Sales and Use Tax Exemption Certificate (Comptroller Form 01-339) at purchase. The Comptroller rule (34 TAC 3.318) limits this to items used solely for rainwater harvesting.
• HOAs: Texas Property Code 202.007 bars most HOAs from banning rain barrels or rainwater systems.
• Your HOA can still bar barrels on common property or between the front of your house and the street. It can require colors that match the house, and it can regulate size, type and screening for barrels visible from the street, a neighbor's lot or a common area, as long as that doesn't make an affordable install impossible.
• The HOA rule does not apply to certain large-city associations that manage developments of 4,000 acres or more.
• Some water-conservation improvements may also qualify for a property tax exemption. Ask your county appraisal district (TWDB).
• Sandy soils need more frequent checks than clay soils.
• TWDB rainwater help: 512-463-8830 or RainWater-Harvesting@twdb.texas.gov.