Tomato Spray for Blossoms Not Setting Fruit

Blossom Set Sprays

• Blossom-set sprays advertise their ability to encourage fruiting in stubborn blossoms with natural plant hormones such as kinetin. These sprays stimulate pollination to "force" fruit production in blooms, without any pollen transfer actually taking place. Spray the liquid on new or stubborn blooms for quick fruit set.

Site and Temperature

• Pollination and fruit set requires a range of considerations and correct growing procedures lead to natural rather than forced pollination. Tomatoes need full sun exposure, air movement and insect involvement to pollinate and produce their fruit. Move non-fruiting tomatoes to an appropriate site to encourage this action. Aggie Horticulture notes also that tomatoes fail at fruit set with night time temperatures under 70 degrees Fahrenheit and day time temperatures under 50 F. Move tomatoes indoors for continued production if your weather cools.

Fertilizer and Soil

• Northern Gardening notes that tomatoes require rich soil to set and grow healthy fruit. Weak, poor or tight soils don't provide enough nutrition for fruit production. Keep tomatoes in rich mixes of topsoil and organic compost for nutrition and drainage, and feed them regularly. Use 6-24-24 or 8-32-16 fertilizer in the early weeks of the season with 10-10-10 fertilizer at mid-season and thereafter. Nitrogen early in the season damages fruit set and leads to lush, vining plants with no fruit. Avoid nitrogen fertilizers until the plants bloom to avoid this problem.

Hand Pollination

• If tomato plants grow indoors, with little air movement or insect activity, pollinate them by hand to encourage fruit production. Tap each bloom to loosen the pollen for self-pollination, or rub clean q-tips over the anthers and stamens of each bloom to transfer pollen.