The effects of amending soil in a planting hole with Viterra hydrogel on the growth, stomatal conductance (gs, and leaf water potential (ψ1) of young ‘Ruby Red’ grapefruit trees (Citrus paradisiMacf.) were assessed during an 18‐months‐long field experiment. The trees were flood‐irrigated when soil available water at 30 cm depth was depleted by 60%. The hydrogel amendments of 1.2 and 2 g.liter‐1of soil in a standard (30 cm diameter) and large (45 cm diameter) planting holes did not affect trunk‐cross‐sectional‐area, canopy width, and tree height. Two months after planting, gsand ψ1were higher on trees planted in large holes with the hydrogel amendment of 2 g.liter‐1compared to trees not treated with the hydrogel. This difference, however, ceased to exist on later dates of measurements. The size of the planting hole had no effect on tree growth.