Tomatoes

Tomatoes are one of the most popular and versatile plants to grow in a garden. By following these guidelines, you can grow and enjoy a bountiful harvest of delicious tomatoes. Whether you’re a beginner or an experienced gardener, tomatoes can be a rewarding and flavorful addition to your garden. There are many kinds of tomatoes and it can be helpful to select them based on growth habit, disease resistance, fruit size, or intended use. Below is an overview for Growing Tomatoes, but you can also check out these Extension Publications for a deeper dive. 

Extension Publication: Growing Tomatoes in the Home Garden

Extension Publication: Selecting Tomatoes for the Home Garden

Growth Habit

1. Determinate (Bush Tomatoes):
   • Description: These plants stop growing, typically at 3 feet tall, and set all of their fruit, which ripens over a 4-6 week period. 
   • Examples: Roma, Celebrity, Patio
   • Uses: Short harvest period ideal for canning and compact growth habit suits containers and small spaces.
2. Indeterminate (Vine Tomatoes):
   • Description: These tomatoes require pruning and physical support, whether caging, staking, or trellising. These varieties continue to grow and produce fruit throughout the growing season until frost.
   • Examples: Cherry, Beefsteak, Brandywine.
   • Uses: Great for continuous harvest.

Disease Resistance

Open Pollinated Seeds

• Description: Open pollinated (OP) means the flowers are fertilized by bees, moths, birds, bats, and the wind or rain. The seed that forms produces the same plant the following year. Some plants are self-pollinators. This means the structure of the flower allows fertilization before it opens. OP varieties grow out true every year. They are genetically diverse, so there can be a lot of variation in the plants and fruits. Since agriculture began about 12,000 years ago, people have been choosing the qualities they like in a plant, such as fruit size, flavor, growth habit, heat and cold tolerance, and uniformity, saved the seed, and continually grew it out year after year. This is plant selection and can only be done with OP seed.
• Examples: Cherokee Purple, Black Krim, Green Zebra.
• Uses: Perfect for gourmet cooking and fresh consumption.
• Heirloom Seeds: In the early 1800’s families grew food on their subsistence farms. They saved seed, selecting for the best traits. As seeds from this era got passed down through the generations, they became heirlooms. All heirlooms are open pollinated, but not all open pollinated plants are heirlooms. Only a small fraction of the plant world is considered heirloom.

Hybrid Seeds

• Description: These are created by cross-pollinating two distinct parent plants selected for desirable traits like disease resistance, yield, or uniformity. The first-generation (F1) plants often show improved vigor, uniformity, and productivity compared to open-pollinated or heirloom types. Seeds saved from hybrid plants may produce offspring that differ from the parent plant, so new plants must be started from purchased hybrid seed each season.
• Examples: Better Boy, Big Beef, Early Girl, Beefsteak, Globe, Cherry, Plum (or paste), Currant
• Uses: Reliable for both home gardens and commercial production.

Growing Conditions

1. Sunlight
   • Requirement: Tomatoes need full sun, at least 6-8 hours of direct sunlight for optimum fruit development and production
2. Soil
   • Type: Fertile, well-drained, loamy soil rich in organic matter.
   • pH: Ideal soil pH is between 6.2 and 6.8.
   • Amendments: Work in compost or well-rotted manure before planting. 
3. Fertilization 
   • All recommendations should be based on a soil test. Instructions on how to collect and submit soil for testing are available from your local UNL Extension office. 
   • If soil nutrients are low, apply 2 to 3 pounds of a complete fertilizer (5-10-10, 6-12-12 or 8-16-16) per 100 square feet of garden area when preparing the soil. 
   • When first fruit is about the size of a half-dollar, scatter one teaspoon of 5-10-5 fertilizer uniformly around each plant 8-10 inches from the stem. Mix the Fertilizer into the top ½ inch of soil and water thoroughly. Repeat this once or twice a month through the rest of the season. 
4. Watering
   • Frequency: Water regularly, providing 1-2 inches of water per week. Adjust based on weather and soil conditions.
   • Method: Water at the base of the plant to keep leaves dry, which helps prevent disease. 
   • Mulching: Apply a 2–3 inch layer of shredded leaves, untreated grass clipping, or straw around the base, keeping mulch 1–2 inches away from the stem to retain moisture and prevent disease.
5. Temperature
   • Optimal Growth: Tomatoes thrive in temperatures between 70°F and 85°F (21°C to 29°C).
   • Cold Protection: Use row covers or cloches to protect young plants from unexpected cold snaps.
   • High-Temperatures: just be aware that High-Temperatures will have an affect on the plants ability for flowering, fruit set, and ripening. 

Planting Tomatoes

1. Starting from Seed
   • Timing: Start seeds indoors 6-8 weeks before the late last spring freeze. 
     1. Visit the Midwest Regional Climate Center for specific information, https://mrcc.purdue.edu/freeze/freezedatetool
   • Method: Sow seeds in seed-starting mix, keep them warm, and ensure seedlings receive plenty of light. Harden off the plants by placing outdoors in the shade before transplanting seedlings into the ground.
2. Planting Transplants
   • Timing: Plant tomatoes outdoors when the soil has warmed to at least 60°F (16°C) and all danger of frost has passed. Visit https://cropwatch.unl.edu/soil-temperature/ for soil temps. 
   • Depth: Plant deeper than they were in the pot; remove leaves from the bottom two-thirds of the plant and bury the stem to encourage a stronger root system.
3. Spacing
   • Determinate: Space plants 18-24 inches apart. Use cages or stakes to support the root system as the plant grows. 
   • Indeterminate: Space plants 24-36 inches apart and provide ample support, such as stakes, cages, or trellises.

Care and Maintenance

Extension Publication: What is Quality in a Tomato?

1. Pruning
   • Indeterminate Varieties: Prune to remove suckers (the shoots that form between the stem and branches) to focus the plant's energy on producing fruit. Approximately 1 month prior to frost, tomato plants can be topped, which involves removing the growing tip of the plant. This can help redirect the plant's energy towards ripening existing fruit rather than producing new growth.
   • Determinate Varieties: Require minimal pruning (Remove any lower leaves that touch the soil) avoid heavy pruning to maximize yield.
2. Staking and Supporting
   • Stakes: Drive stakes into the ground at planting time. Tie the plants to the stakes as they grow.
   • Cages: Tomato cages provide all-around support and are ideal for both determinate and indeterminate varieties.
   • Trellis: Install trellis posts or panels before the plants get big to avoid root damage later. For string systems, sink sturdy posts 12–18 inches deep and stretch a horizontal bar or wire at the top (6–7 feet high). Don’t let vines sprawl—attach new growth to the trellis regularly.
3. Fertilizing
   • Initial Feeding: Apply a balanced fertilizer at planting.
   • Ongoing Feeding: Side-dress with compost or use a tomato-specific fertilizer every 3-4 weeks during the growing season, based on soil test results. 
4. Mulching
   • Type: Use organic mulch like straw, non-treated grass clippings, or shredded leaves to help conserve moisture, reduce weeds, and prevent soil-borne diseases.
   • Application: Apply a 2-3 inch layer around the base of the plants, keeping it away from the stems.

Common Pests and Diseases

Extension Publication: Leaf and Fruit Diseases in Tomatoes

1. Pests
   • Aphids: Small insects that suck plant sap. Manage with insecticidal soap or neem oil. hles-abl-aphids
   • Tomato Hornworms: Large green caterpillars that eat leaves. Handpick or use biological controls like Bacillus thuringiensis (Bt). hles-abl-tomato-tobacco-hornworms
   • Whiteflies: Tiny white insects that can transmit diseases. Manage with neem oil.
2. Diseases
   • Early Blight: Fungal disease causing dark spots beginning on lower more mature leaves. Prevent with crop rotation, selecting more tolerant varieties (like Jetstar), mulching, and good fall cleanup. Manage with fungicide applications.
   • Late Blight: Devastating fungal disease. Prevent by choosing resistant varieties and practicing good fall cleanup, crop rotation, and proper plant spacing, and avoiding overhead watering.
3. Physiological Issue
   • Blossom End Rot: Caused by impaired calcium transport in the plant due to inconsistent soil moisture. Prevent with consistent watering and mulching.

Harvesting

1. Timing
   • When to Harvest: Pick tomatoes when they are fully colored but still firm. Tomatoes continue to ripen after being picked.
   • Ripening Off the Vine: If frost threatens, pick mature green tomatoes and let them ripen indoors.
2. Method
   • Harvesting Technique: Use scissors or a sharp knife to cut tomatoes from the vine, leaving a small portion of the stem attached to the fruit.
   • Storage: Store harvested tomatoes at room temperature out of direct sunlight. Avoid refrigeration as it can affect the flavor.

Variety Suggestions

1. Cherry Tomatoes
   • Varieties: Sun Gold, Sweet 100, Black Cherry
   • Description: Small, sweet tomatoes that are perfect for snacking and salads.
2. Slicing Tomatoes
   • Varieties: Big Boy, Brandywine, Beefsteak
   • Description: Large tomatoes with excellent flavor, ideal for sandwiches and slicing.
3. Paste Tomatoes
   • Varieties: Roma, San Marzano, Amish Paste
   • Description: Dense, meaty tomatoes that are perfect for sauces and canning.

Check out the following links for more information about recipes and preserving your bountiful harvest of Tomatoes

• https://food.unl.edu/article/tomatoes/ 
• https://food.unl.edu/article/tomatoes-and-tomato-products/
• https://food.unl.edu/article/freezing-tomatoes/
• https://food.unl.edu/food-preservation/drying/