Heat, humidity and the availability of bumblebees all affect whether your tomato plants will pollinate and produce tomatoes. Bumblebees typically pollinate tomato plants by gripping the flowers with their back legs while vibrating their wings. This vibration stimulates pollination. But in high humidity, pollen may be too sticky to shed. Or, if humidity levels are low, pollen may not be able to stick to the stigma to start fertilization. Pollinate your tomato plants by hand to ensure good fruit sets for harvest time.
Select a day when temperature are 60 to 70 degrees F to pollinate tomato plants. For outdoor plants, where you may not be able to control heat levels, pollinate your plants several days in a row to ensure fertilization.
Place a soft-bristled toothbrush head on your electric toothbrush holder so that you don't harm your tomato plants in the pollination process.
Turn your electric toothbrush on and touch the bristles gently to the backside of the petals of a flower for just a few seconds, and then release the brush. Do not touch the face of the flower. Each flower has both the female and male reproductive organs so this should help pollen to fall to the stigma.
Place the toothbrush on the stem beneath the flower and let it vibrate a few second before releasing it.
Repeat vibrating the brush on each flower's petals and stem to stimulate pollination. Repeat the process every two days to be sure you are pollinating as many flowers as possible and that fruits set on your plants.