Grape tomatoes may be tiny, but they're full of sweet, juicy flavor, the perfect size for snackability or for tossing on a green salad. Because of their diminutive size, they're difficult to grow and package. As a result, grape tomatoes are considerably more expensive at the market. However, grape tomatoes can be grown inexpensively in your backyard or in a patio container.
Start grape tomato seeds indoors eight weeks before the last expected frost in your area. Fill a planting tray with dampened commercial seed-starting mixture. Plant the grape tomato seeds 2 inches apart and cover them with 1/4 of an inch of the seed-starting mixture.
Place the planting tray on a seed-starting mat that will keep the bottom of the tray between 70 and 90 degrees F. Place the tray in a warm room if a seed-starting mat is unavailable. Place the tray on top of a warm appliance, such as a refrigerator, to attain the required temperature, if necessary.
Watch for the seeds to sprout, remove the planting tray from the seed-starting mat and place the tray under a grow light, 2 to 4 inches from the bulb. Leave the grow light turned on no longer than 18 hours each day. Move each seedling into an individual 4-inch container when the seedlings have two sets of leaves.
Move the grape tomato plant outdoors when the daytime temperature is between 60 and 70 degrees F and when nighttime temperatures are at least 55 degrees F. Acclimate the grape tomato plants to the outdoor environment gradually. Put them outdoors for an hour on the first day. Add an hour a day, and plant them when they're accustomed to being outdoors for six hours.
Prepare a garden bed or planting container in a sunny spot ahead of time. Till or shovel to cultivate the soil to a depth of 10 to 12 inches, then mix in 2 to 3 inches of compost or well-rotted manure, if the grape tomato are going to be planted in the ground. Fill a container with commercial potting soil and add a scoop of compost or well-rotted manure if the plants are going to potted.
Dig a hole with a shovel or trowel. Plant the grape tomato plants up to the second set of leaves. Tamp the soil down around the plant. Water the grape tomato plants throughly, then give them about 1 inch of water every week.
Fertilize the grape tomato plants every 2 to 3 weeks during the growing season with a fertilizer formulated for tomatoes. Apply the fertilizer according to the package directions.
Provide tomato cages or stakes for the grape tomato vines to crawl on. Install the support at the time the grape tomatoes are planted for best results. Waiting to cage or stake the tomatoes risks driving the stake or support into the root system.