Growing Tomatoes - The Backyard Pantry

Growing tomatoes (Solanum lycopersicum) in Missouri (Zone 6b-7a) is a popular and rewarding endeavor, as they thrive in warm, sunny climates and provide a bountiful harvest. Here’s a detailed guide for successfully growing tomatoes in your region:

1. Choose the Right Variety

Variety Selection: There are many types of tomatoes to choose from, including:
- Determinate (Bush) Varieties: These tomatoes grow to a certain size, set fruit, and then stop growing. They are ideal for smaller spaces or container gardening.
  - ‘Roma’: A classic paste tomato, great for sauces and canning.
  - ‘Celebrity’: A reliable, early-maturing variety with good disease resistance.
- Indeterminate (Vining) Varieties: These tomatoes continue growing throughout the season and produce fruit until frost. They require more space and a strong trellis or cage.
  - ‘Better Boy’: A classic, large slicing tomato.
  - ‘Brandywine’: A flavorful heirloom tomato, known for its large fruit and rich taste.
- Cherry and Grape Tomatoes: These smaller varieties are great for snacking and salads.
  - ‘Sweet 100’: A small, sweet cherry tomato that produces high yields.
  - ‘Juliet’: A popular grape tomato with a sweet flavor.
Disease Resistance: In Missouri’s humid climate, look for varieties with resistance to early blight, late blight, and Verticillium wilt.

2. Planting Time

Indoor Starting: Start tomato seeds indoors 6–8 weeks before the last expected frost (typically early March to mid-March in Zone 6b-7a). Tomatoes need a long growing season to reach maturity.
Outdoor Planting: Transplant seedlings outdoors after the last frost date, which is typically around mid-May in Missouri. Soil temperatures should be consistently 60–70°F or higher before transplanting.
Frost-Free Period: Tomatoes need a frost-free growing season, typically from late May to early October in Missouri, depending on the variety. Keep an eye on the first expected frost date in the fall.

3. Site Preparation

Soil Requirements: Tomatoes prefer well-drained, fertile soil rich in organic matter with a slightly acidic pH of 6.0–6.8. Incorporate compost or well-rotted manure to improve soil structure and fertility.
Soil Depth: Tomatoes have deep root systems, so prepare the soil to a depth of 12–18 inches for optimal root growth.
Location: Choose a full-sun location that receives at least 6–8 hours of direct sunlight per day. Tomatoes need plenty of sunlight to produce healthy fruit.
Spacing: Space plants 18–36 inches apart, depending on the variety. For indeterminate varieties, use strong cages or trellises to support the plant and give it enough space to grow. Leave 4 feet between rows to allow for air circulation and reduce disease risks.

4. Planting

Transplanting: When transplanting seedlings outdoors, ensure the plants are hardened off first by gradually exposing them to outdoor conditions for a few hours each day, increasing the exposure over 7–10 days.
Planting Depth: Tomato seedlings can be planted deeper than they were in their pots. Plant them up to the first set of leaves to promote strong root development. This encourages the plant to grow more roots along the buried stem.
Soil Temperature: Tomatoes thrive when soil temperatures are 60–70°F. If soil is too cool, use black plastic mulch to warm the soil before planting.
Watering: Water the seedlings thoroughly after planting, ensuring the soil is moist but not waterlogged. After planting, water deeply to establish the plants and encourage deep rooting.

5. Watering and Maintenance

Watering Needs: Tomatoes need consistent moisture to grow well and prevent problems like blossom end rot. Water deeply and consistently to maintain moist soil, but allow the soil surface to dry out slightly between waterings to prevent root rot.
Watering Method: Use a drip irrigation system or soaker hoses to water at the base of the plants, which helps prevent disease by keeping the foliage dry.
Weeding: Mulch around your tomato plants with straw, grass clippings, or wood chips to help suppress weeds, retain moisture, and regulate soil temperature.
Fertilization: Tomatoes are heavy feeders, so feed them with a balanced fertilizer (such as 10-10-10) at planting time, and again when the first fruit begins to set. Consider a tomato-specific fertilizer that is higher in potassium and phosphorus for better fruit development.
Pruning: Regularly remove suckers (the small shoots that grow between the main stem and branches) on indeterminate varieties. This helps focus energy on fruit production and keeps the plant manageable. However, determinate varieties do not need heavy pruning.

6. Growth and Flowering

Plant Growth: Tomatoes are typically indeterminate (vining) or determinate (bush) types. Indeterminate varieties will continue to grow and produce fruit throughout the season, while determinate varieties have a more compact growth habit and produce all their fruit at once.
Flowering: Tomatoes produce yellow flowers that eventually turn into fruit. The first flowers usually appear 50–70 days after transplanting, depending on the variety.
Pollination: Tomatoes are self-pollinating, so you don’t need multiple plants for fruit production. However, bees and wind help with the process. If needed, gently shake the plant to encourage pollen movement.

7. Pest and Disease Management

Common Pests:
- Aphids: These pests suck sap from the plants and can spread viruses. Control them by spraying with insecticidal soap or introducing ladybugs.
- Tomato Hornworms: Large green caterpillars that can defoliate your plants. Handpick or use Bt (Bacillus thuringiensis) to control them.
- Whiteflies: Tiny white insects that can weaken the plant and spread disease. Use yellow sticky traps to reduce their population.
Diseases:
- Early Blight: This fungal disease causes spots on leaves and stems. Avoid overhead watering, ensure good air circulation, and use fungicides if necessary.
- Late Blight: A serious disease that causes rapid wilting and rotting of plants. Prevent this by planting resistant varieties, practicing crop rotation, and removing infected plants immediately.
- Verticillium Wilt: A soil-borne disease that causes wilting and yellowing of leaves. Choose resistant varieties and avoid planting tomatoes in the same soil year after year.
- Blossom End Rot: This condition causes black, sunken spots on the bottom of the fruit. It’s caused by calcium deficiency and irregular watering. Prevent it by keeping soil consistently moist and adding lime to the soil to correct calcium deficiencies.

8. Harvesting

Timing: Tomatoes are ready for harvest when they have fully ripened, and the fruit is firm but slightly soft to the touch. The exact time depends on the variety, but typically 60–90 days after transplanting.
Signs of Maturity: Look for full color (red, yellow, orange, or purple, depending on the variety), a slight softness, and a sweet aroma from the fruit. If the fruit is still green, it will ripen off the vine if stored in a warm location.
How to Harvest: Use sharp scissors or pruning shears to cut the tomatoes from the vine, leaving a small portion of the stem attached. Gently twist or pull the tomato off to avoid damaging the plant.

9. Storage

Short-Term Storage: Fresh tomatoes can be stored at room temperature until they ripen. Once ripe, store them in the refrigerator for up to 1 week. However, storing them in the fridge can reduce flavor, so it’s best to store fully ripe tomatoes at room temperature until they’re eaten.
Long-Term Storage:
- Canning: Tomatoes can be canned as whole tomatoes, sauces, or salsas. Properly processed tomatoes can last up to a year in a cool, dark pantry.
- Freezing: Tomatoes can be frozen, though they may lose some texture once thawed. To freeze, blanch tomatoes, peel them, and store in freezer bags for up to 6 months.
- Drying: Sun-drying or oven-drying tomatoes are great options for preserving them for months.

10. Considerations for Missouri’s Climate

Heat and Humidity: Missouri’s hot and humid summers can cause disease problems like early blight and late blight. Use disease-resistant varieties, and make sure to provide adequate spacing and air circulation.
Rainfall: Missouri can have heavy rainfall, which may contribute to fungal diseases. Use mulch to keep water off the soil and avoid splashing it onto the leaves.
Frost Sensitivity: Tomatoes are very sensitive to frost, so it’s essential to plant them after the last frost and harvest before the first frost (typically mid-October in Missouri).

11. Challenges

Pests and Diseases: Regular inspection for pests like tomato hornworms and aphids can help keep them under control. Be proactive about managing diseases like late blight and early blight by rotating crops and practicing good sanitation.
Heat Stress: During extreme heat, tomatoes may have issues with fruit set or develop blossom drop. Provide some shade during the hottest part of the day if temperatures exceed 90°F.

By following these steps, you’ll be able to grow tomatoes successfully in Missouri’s climate and enjoy a plentiful harvest. Whether you’re growing large slicers, cherry tomatoes, or paste tomatoes for sauces and canning, you’ll have fresh, homegrown produce throughout the season. Let me know if you have any further questions! We are always happy to help!