The effect of some commercial stimulants on inducing resistance in tomato cultivars K186 F₁ and 023 F₁ to two-spotted spider mites (Tetranychus urticae Koch) was evaluated. The experiment was conducted under open-field conditions during the 2017 and 2018 summer seasons. Stimulants were applied to field-grown tomato plants after observing T. urticae individuals. The population of the movable stages of T. urticae at the start of the application and weekly intervals was counted as a measure of plant resistance. The initial population at three weeks after transplanting on both cultivars was within the economically safe range (< 1 mite/leaflet) for both seasons. The population of T. urticae increased gradually with plant age. The applied stimulants delayed the arrival of the economically significant damage until the 11 weeks after transplanting, especially with the spraying of Silical® (45% silicon oxide, 9% calcium, and 0.9% boron) and Stansh® (35% silicon oxide, 11.5% potassium oxide, and 13.4% silicon). The density of glandular and non-glandular trichomes on tomato leaves for various treatments was assessed at 13 weeks after transplanting. The stimulants had a significant positive effect on trichome density. The highest densities were found with Silical®, Stansh®, and Ultrafit® (38% salicylic acid, 2.8% nitrogen, 6.2% phosphor, and 23% potassium) for both cultivars. The foliar essential oil in Silical®, Ultrafit®, and control treatments was analyzed using the GC-MS technique. Silical® and Ultrafit® spraying stimulated tomato leaves to synthesize compounds that have acaricide activity. Chlorfenapyr was synthesized in both cultivars, and 2-dehydro-1,8-cineole, -gurjunene, -humulene, and heptacosane were synthesized in cultivar 023 F₁. Silical® and Ultrafit® spraying also increased the synthesis of some monoterpenoids that helped tomatoes resist T. urticae. Induced tomato resistance does not eliminate pest problems, but helps reduce pest populations and damage below the economic threshold. Silicon compounds can be accepted as part of integrated pest management, which must be carefully chosen for long-term agricultural sustainability.