Three different injectors, each 25mm in length and with diameters of 6, 4, and 3mm, respectively, were tested with low-pressure injections of 250ml of water into 23 different species of fruit-trees, woodland and ornamental trees at different times of year. The 6 and 4mm injectors performed well, yielding uptake of 75-100% of water volume 1 or 48h after injection, depending on the species; however, the ornamental species Melia azedarach did not perform well with all three injectors. The 3mm injector yielded highly irregular results. The 4mm injector could substitute the more widely-used 6mm injector in most cases, with the added advantage of reducing healing time. Injection uptake rates were greater on clear than on rainy days, this difference increasing with smaller-diameter injectors. Prunus species took up a high water volume when injected prior to budbreak, and this could avoid leaf burning caused by later injections of some chemicals. Uptake rates were lower during the winter rest period than during the peak growth season (spring). All these factors are to be taken into account in order to ensure the best and most efficient use of low-pressure injection of chemicals in agricultural, forestry or landscape practices.