Stored nonstructural carbohydrates are a primary source of reserve energy in vegetative organs of warm‐season grasses. Research is needed concerning the influence of potassium on carbohydrate levels in turfgrasses. Four K rates ranging from 24 to 390 kg ha⁻¹ per growing month were applied twice monthly from 1992 to 1994 to ‘Tifdwarf’ and ‘Tifway’ bermudagrasses [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt Davy] field grown on Uchee loamy sand (loamy, siliceous, thermic Arenic Hapluduit) and sand‐peat (9:1 by volume) dium. Root + rhizome and shoot + stolon samples were evaluated monthly for total non‐structural carbohydrate (TNC) concentrations by means of near infrared reflectance spectroscopy. TNC concentrations varied among cultivars, plant parts, and time of year. Tifdwarf produced 30% greater root + rhizome TNC concentration and 55% greater shoot + stolon concentration than Tifway. Higher K rates either did not influence or reduced root + rhizome TNC concentrations compared to low K rates. Correlation analysis indicated that root + rhizome yields and TNC concentrations were negatively influenced by temperature. Carbohydrate and root + rhizome yield responses suggesthere is no benefit to applying K at rates beyond those that provide sufficient K levels for normal growth.