The ability of roots of acid soil tolerant and intolerant wheat (Triticum aestivumL.) genotypes to grow into and extract water from subsoil acid environments was investigated. The method used to test this minimized the complicating influence of another effect of acidity, interference with uptake and utilization of nutrients. Root growth by 4‐day‐old seedlings estimates plant ability to explore acid subsoils. Root lengths were measured in eight wheat cultivars exhibiting varied tolerance to an acid soil treated with five levels of Ca(OH)2. Length of the longest root per plant was an indicator of plant response, and decreased linearly with soil solution Al concentration. The cultivars were ranked in order of tolerance from lowest to highest by root length (cm) in the zero lime treatment (434 μMAl in soil solution): Hart 1.8, Arthur 2.0, Wampum 4.0, Caldwell 5.5, Logan 6.3, Edwall 7.3, Titan 8.0, and Yecorra Rojo 8.2. Acid‐tolerant Yecorra Rojo was able to extract 2 to 4 times more water than acid‐sensitive Wampum and Hart cultivars from unlimed subsurface soil.