Tomato
Solanum lycopersicum. Tomatoes are members of the nightshade family, along with potatoes, peppers, and eggplants. Tomatoes are one of the most versatile and beloved fruits in the culinary world, prized for their juicy texture and rich flavor. They come in a diverse range of shapes, sizes, and colors, from cherry tomatoes to beefsteak varieties, and can be used fresh in salads, sandwiches, and salsas or cooked in soups, stews, and of course pasta sauces. Tomato plants can be determinate or indeterminate. Determinate plants have a bushy growth habit. Indeterminate plants have a vining sprawling habit which need to be trellised.
Starting Seeds
Tomato seeds germinate best in warm soil temperatures. The ideal range for germination is between 70°F (21°C) and 85°F (29°C). However, the optimal temperature is around 75°F to 80°F (24°C to 27°C).
Direct sow only if you live in a warm climate. Otherwise start seeds indoors 8-12 weeks prior to your last frost date.
When to Plant Out
Tomatoes should be transplanted outdoors after the last expected frost date once the weather has warmed, and the soil temperatures consistently reach at least 50°F (10°C) or warmer.
Light
Full sunlight: at least 6-8 hours a day.
Space
Space plants 12″-24″ apart. Indeterminate varieties should be trellised. Be sure to check the seed packet for specifics on your variety’s size.
Temperature
Tomatoes thrive in warm temperatures, with optimal daytime temperatures ranging between 70°F and 85°F (21°C to 29°C). While established plants in the Fall can tolerate cooler nighttime temperatures, young tomato plants perform best when nighttime temperatures remain above 60°F (15°C), with temperatures below 50°F (10°C) stunting growth. Conversely, daytime temperatures above 85°F to 90°F (30°C to 32°C) and nighttime temperatures above 75°F (24°C) will halt growth and often cause flowers to fail to pollinate until temperatures fall again. Tomatoes are not hardy and will be killed by frost.
Water
Keep the soil consistently moist. Water at the base of the plants to keep the foliage dry and reduce the risk of diseases.
Pruning
Determinate tomato varieties generally should not be pruned as they have a predetermined growth habit and produce fruit over a relatively short period. Pruning will reduce overall yields.
Indeterminate tomato varieties continue to grow and produce fruit until killed by frost. Suckers are the small shoots that develop in the leaf axils (the angle between the stem and a leaf). Pinch off suckers as soon as they are noticeable. Thin out excess foliage, especially in the interior of the plant, to improve airflow. Remove any dead or diseased branches.
Harvesting
Tomatoes are typically ready for harvest when they reach their mature color and size, which varies depending on the variety. Ripe tomatoes will often develop a deep, vibrant color and feel slightly soft when gently squeezed. If frost threatens, green tomatoes can be harvested and ripen indoors.
Propagation
Tomatoes are commonly propagated from seeds. When saving seeds from tomato plants, it’s important to ensure that they have not been cross-pollinated. Different varieties of tomatoes will cross-pollinate each other.
Other Considerations
Smaller varieties can be container friendly and may even be suitable for growing indoors if provided with a grow light.