Take your tomato growing to the next level with seed starting, succession planting, advanced pruning, and season extension techniques. Learn to grow more tomatoes than ever before.
Sarah Green
Horticulturist and garden expert with 15+ years of experience growing vegetables, herbs, and houseplants. Certified Master Gardener.
Introduction
You've successfully grown tomatoes and want to take your skills to the next level. This intermediate guide covers seed starting, advanced variety selection, pruning techniques, and methods to extend your harvest season.
Starting Tomatoes from Seed
Growing from seed opens up hundreds of variety options not available as transplants.
Why Start from Seed?
- Access to 3,000+ tomato varieties vs. 20-30 as transplants
- Grow heirloom varieties passed down for generations
- Save money (seed packet = dozens of plants)
- Complete control over growing conditions
- Earlier start to the season
Timing Your Seed Start
Start seeds indoors 6-8 weeks before your last expected frost date.
| Region | Last Frost Date | Start Seeds |
|---|---|---|
| Deep South (zones 8-10) | Feb-March | December-January |
| Mid-Atlantic (zones 6-7) | April-May | February-March |
| Northern (zones 3-5) | May-June | March-April |
Seed Starting Setup
Essential equipment:
- Sterile seed-starting mix
- Cell trays or small pots with drainage
- Humidity dome or plastic wrap
- Heat mat (speeds germination significantly)
- Grow lights (14-16 hours daily)
- Small fan for air circulation
Seed Starting Process
- Moisten seed-starting mix until it holds together when squeezed
- Fill cells and press down lightly to remove air pockets
- Plant seeds 1/4 inch deep, 2-3 seeds per cell
- Cover and place on heat mat at 75-85°F (24-29°C)
- Remove cover when seeds sprout (5-10 days)
- Move to lights immediately after sprouting
- Thin to one seedling per cell after first true leaves appear
Pro Tip: Keep lights 2-3 inches above seedlings and raise as they grow. This prevents leggy, weak stems.
Potting Up
When seedlings have 2-3 sets of true leaves:
- Prepare 4-inch pots with potting mix
- Water seedlings before transplanting
- Bury stem up to lowest leaves
- Return to lights, begin fertilizing at 1/4 strength
Advanced Variety Selection
Understanding Variety Categories
By Size:
- Currant/Grape: Under 1 oz, prolific producers
- Cherry: 1-2 oz, sweet, ideal for snacking
- Saladette/Plum: 2-4 oz, meaty, great for sauces
- Slicers: 4-8 oz, classic sandwich tomatoes
- Beefsteak: 8 oz to 2+ lbs, meaty giants
By Growth Habit:
- Determinate: Bush type, sets fruit once, great for canning
- Semi-determinate: Compact but produces longer than determinate
- Indeterminate: Vining, produces until frost
By Genetics:
- Heirloom: Open-pollinated, saved 50+ years, unique flavors
- Hybrid (F1): First-generation cross, disease resistance, uniformity
- Open-pollinated: Stable variety, seeds breed true
Recommended Intermediate Varieties
| Variety | Type | Flavor Profile | Disease Resistance | Notes |
|---|---|---|---|---|
| Cherokee Purple | Heirloom/Indeterminate | Complex, smoky-sweet | Low | Iconic heirloom |
| San Marzano | Heirloom/Indeterminate | Low acid, meaty | Moderate | Ultimate sauce tomato |
| Sun Gold | Hybrid/Indeterminate | Tropical, sweet | High | Best cherry by many accounts |
| Mortgage Lifter | Heirloom/Indeterminate | Sweet, mild | Low | Huge fruits up to 2 lbs |
| Mountain Magic | Hybrid/Indeterminate | Rich, balanced | Very High | Excellent blight resistance |
| Black Krim | Heirloom/Indeterminate | Intense, salty-sweet | Low | Striking dark color |
Disease Resistance Codes
When shopping for seeds, you'll see letters indicating resistance:
- V: Verticillium wilt
- F/FF: Fusarium wilt (races 1 and 2)
- N: Nematodes
- T/TMV: Tobacco mosaic virus
- A: Alternaria
- St: Stemphylium (gray leaf spot)
- TSWV: Tomato spotted wilt virus
Note: For regions with known disease pressure, prioritize varieties with relevant resistance codes.
Pruning and Training Techniques
Why Prune Tomatoes?
- Larger, earlier ripening fruits
- Better air circulation (reduces disease)
- Easier to manage and support
- Directs energy to fruit production
Understanding Suckers
Suckers are shoots that grow in the "V" between the main stem and branches. They become new stems if left to grow.
Pruning strategies:
- Single-stem pruning: Remove ALL suckers for maximum fruit size
- Double-stem pruning: Allow one sucker below first flower cluster
- Minimal pruning: Remove only suckers below first flower cluster
How to Remove Suckers
- Small suckers (under 2 inches): Pinch with fingers
- Larger suckers: Use clean pruning shears
- Remove in morning when plants are turgid
- Don't remove leaves unless they're diseased or blocking airflow
Lower Leaf Removal
As plants mature, remove lower leaves that:
- Touch the soil
- Show disease symptoms
- Block airflow
- Are completely shaded
Warning: Never remove more than 25% of foliage at once. This stresses the plant and can cause sunscald on fruits.
Succession Planting
Extend your harvest by planting at different times:
Strategy 1: Staggered Transplanting
Plant new seedlings every 2-3 weeks from last frost until 12 weeks before first fall frost.
Strategy 2: Mix Early and Late Varieties
| Category | Days to Maturity | Examples |
|---|---|---|
| Early | 50-65 days | Early Girl, Fourth of July |
| Mid-season | 65-80 days | Celebrity, Better Boy |
| Late | 80-90+ days | Brandywine, Big Rainbow |
Strategy 3: First and Second Crops
In long-season areas (zones 8+), plant a spring crop and a fall crop.
Season Extension
Extending the Spring
- Wall o' Waters: Create warm microclimate for transplanting 2-4 weeks early
- Cold frames: Start hardening off earlier
- Row covers: Protect from late frosts
- Black plastic mulch: Warms soil faster
Extending the Fall
- Pinch growing tips: 4 weeks before frost, redirect energy to ripening
- Remove flowers: Stop fruit set 4 weeks before frost
- Row covers: Protect from early frosts
- Harvest green: Ripen indoors when frost threatens
Indoor Ripening
Green tomatoes ripen best at 65-70°F with moderate humidity:
- Place in single layer, not touching
- Add a banana or apple for ethylene (speeds ripening)
- Check daily and remove ripened fruits
- Can take 2-4 weeks depending on maturity
Soil Building and Fertility
Understanding Tomato Nutrient Needs
| Stage | Primary Need | Signs of Deficiency |
|---|---|---|
| Seedling | Phosphorus | Purple-tinged leaves |
| Vegetative | Nitrogen | Pale green/yellow leaves |
| Flowering | Phosphorus, Potassium | Poor flowering, weak stems |
| Fruiting | Potassium, Calcium | Blossom end rot, poor color |
Organic Fertility Program
At planting:
- Compost (2-3 inches worked in)
- Bone meal (phosphorus)
- Kelp meal (trace minerals)
During growth:
- Compost tea or fish emulsion every 2-3 weeks
- Side-dress with compost monthly
- Foliar feed with seaweed extract
Calcium for Preventing Blossom End Rot
Calcium uptake depends on consistent watering. If you have persistent BER:
- Add gypsum or agricultural lime to soil
- Use calcium foliar spray
- Maintain mulch and consistent irrigation
Companion Planting
Beneficial Companions
| Companion | Benefit |
|---|---|
| Basil | Repels aphids and whiteflies, may improve flavor |
| Marigolds | Deters nematodes and many insects |
| Carrots | Loosen soil, don't compete for nutrients |
| Parsley | Attracts beneficial insects |
| Borage | Attracts pollinators, deters hornworms |
Plants to Avoid
- Brassicas (cabbage, broccoli): Compete for nutrients
- Fennel: Inhibits tomato growth
- Corn: Attracts shared pest (corn earworm/tomato fruitworm)
- Nightshades nearby: Increases disease pressure
Saving Tomato Seeds
Only save seeds from open-pollinated and heirloom varieties (not hybrids).
Fermentation Method
- Choose fully ripe, disease-free fruit
- Scoop seeds and gel into a jar
- Add equal amount of water
- Cover loosely and let ferment 2-3 days
- Stir daily until mold forms on surface
- Add water and pour off floating debris
- Rinse clean seeds in strainer
- Dry on paper plate or coffee filter
- Store in paper envelope in cool, dry place
Seeds remain viable for 4-6 years when stored properly.
Conclusion
These intermediate techniques—seed starting, strategic variety selection, proper pruning, and season extension—will dramatically improve your tomato harvests. The key is experimentation: try new varieties, test different pruning methods, and keep notes on what works in your specific garden.
Ready for more? Our Advanced Guide covers intensive production methods, organic pest management, and building long-term soil health.
Related Topics
Share This Guide
Related Guides
Continue learning with these related guides
How to Grow Quinoa: Complete Planting & Harvest Guide
Learn how to grow quinoa with this complete planting and harvest guide. This ancient Andean superfood grain is surprisingly easy to grow in home gardens — drought-tolerant, cold-hardy, and ready in 90-120 days. This guide covers varieties, direct sowing, the critical dry harvest window, threshing and winnowing, saponin removal, and solutions to common problems.
How to Grow Peanuts: Complete Planting & Harvest Guide
Learn how to grow peanuts with this complete planting and harvest guide. Peanuts are one of the most fascinating crops — flowers bloom above ground, then bury themselves to develop nuts underground. This guide covers varieties, planting, the unique pegging process, hilling, when to harvest, curing for maximum flavor, and solutions to common problems.
How to Grow Taro: Complete Planting & Harvest Guide
Learn how to grow taro with this complete planting and harvest guide. This ancient tropical staple — the source of poi, taro chips, and bubble tea — produces starchy, nutty corms and edible leaves. This guide covers growing from corms, water vs dryland methods, the long warm season required, elephant ear ornamental vs edible varieties, harvesting, and solutions to common problems.
How to Grow Cassava (Yuca): Complete Planting & Harvest Guide
Learn how to grow cassava (yuca) with this complete planting and harvest guide. This tropical staple feeds 800 million people worldwide and produces massive starchy roots from simple stem cuttings. This guide covers propagation, the 8-18 month growing timeline, the critical safety rule about cooking, harvesting techniques, and solutions to common problems.