Begonias are among the most rewarding flowers to grow, bringing color to containers, hanging baskets, and garden beds from spring through fall. Known for their adaptability, begonias thrive in both sun and shade and make excellent choices for patios and indoor displays. While many gardeners purchase begonias as transplants, starting begonias from seed gives you greater variety, healthier plants, and a cost-effective way to fill your garden with blooms.

In this guide, we’ll cover everything you need to know about starting begonia seeds, especially pelleted begonia seeds. From germination to transplanting, plus common pests and diseases like Botrytis, you’ll learn the exact steps to produce high-quality begonia plants.

👉 Looking for seeds? Shop Bulk Begonia Seeds or browse Smaller Packs of Begonia Seeds.

📌 Related Reading: When to Start Seeds Indoors by Zone (Complete Guide)

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Why Start Begonias from Seed?

• More variety: Growing begonias from seed allows you to explore unique colors and growth habits.

• Cost savings: Seeds are far more economical than buying mature plants.

• Control: You can manage soil, lighting, and fertilizers to produce stronger, healthier plants.

• Pelleted seed advantage: Pelleted begonia seeds are coated for easier handling and precision sowing—especially useful in professional nurseries with vacuum seeders.

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Step 1: Preparing to Sow Begonia Seeds

Recommended Trays and Media

• Tray size: A 288-cell tray works best for starting pelleted begonia seeds.

• Seeds per cell: Sow 1 pelleted seed per cell for uniform growth.

• Media: pH 5.5–5.9; EC 0.5–0.75 mS/cm. Use a light, well-draining seed-starting mix.

👉 In our nursery, we use a vacuum seeder to ensure precision sowing. This reduces waste and guarantees consistent spacing.

Conditions for Germination (Stages 1 & 2)

• Temperature: 72–78°F (23–25°C)

• Moisture: Level 5 (saturated) until germination is complete.

• Light: Not required for germination.

• Seed cover: Do not cover begonia seeds; they need light air exposure.

• Time: Germination typically takes 14 days.

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Step 2: Young Plant Production (Stages 3 & 4)

Once seedlings emerge, adjust conditions to encourage strong root and leaf development.

• Temperature: Day 70–72°F, Night 68–70°F.

• Lighting: Day extension to 14 hours is required. Grow lights are essential indoors, as begonias are obligate long-day plants. Light intensity of 1,500–3,000 foot candles works best.

• Moisture: Alternate between level 2 (medium) and level 4 (wet) to encourage healthy growth and prevent algae.

• Fertilizer: 100–150 ppm N during early stages.

• Plug grow time: 7–9 weeks in 288-cell trays.

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Step 3: Transplanting and Finishing

When roots fill the cell, transplant directly into final containers: pints, quarts, gallons, or hanging baskets.

• Planting depth: Do not bury plugs—keep the crown exposed to prevent crown rot.

• Spacing: Begonias will grow 12–16” tall and 16–20” wide.

• Light needs: Full sun to shade, adaptable to a wide range of exposures.

• Fertilizer: Increase to 200–250 ppm N for finishing.

• Moisture: Alternate between level 2 and 4—never keep soil constantly soggy.

• Pinching: Not required.

• Growth regulators: Usually unnecessary with proper moisture, fertilizer, and light.

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Managing Pests and Diseases

Common Pests

• Fungus gnats

• Shore flies

• Thrips

Common Diseases

• Botrytis (gray mold): Often develops in high humidity. Avoid overhead watering and provide good airflow.

• Pythium: Root rot caused by poor drainage. Use clean trays and sterilized media.

👉 Pro tip: Irrigate early in the day to prevent leaf scorch under high light and reduce disease pressure.

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Why Use Pelleted Begonia Seeds?

Pelleted seeds are coated for easier handling and precise sowing. Since begonia seeds are naturally tiny and difficult to see, the pelleting process makes them ideal for vacuum seeding and ensures even distribution in trays. This results in:

• Higher germination success

• More uniform seedlings

• Less seed waste

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Growing Begonias in Containers and Hanging Baskets

Begonias shine in patio pots and baskets due to their semi-trailing habit. They:

• Fill containers with lush foliage

• Produce season-long blooms

• Tolerate both shade and sun

👉 For large-scale plantings, explore Bulk Seed Packs. For smaller home projects, see Smaller Seed Packs.

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❓ FAQ: Starting Begonia Seeds

Q1. How long do begonias take to germinate?
About 14 days under 72–78°F and saturated media conditions.

Q2. Do begonia seeds need light to germinate?
No, they do not require light for germination—but strong grow lights are necessary after emergence.

Q3. Can I grow begonias without grow lights?
Not successfully indoors. Begonias require long-day conditions with at least 14 hours of light for strong growth.

Q4. What tray size is best for starting begonia seeds?
288-cell trays are ideal for uniform plugs and easy transplanting.

Q5. Are pelleted begonia seeds better than raw seeds?
Yes. Pelleted seeds are easier to handle, sow more uniformly, and are more reliable in professional and home settings.

Q6. What diseases should I watch for?
Botrytis and Pythium are the most common. Prevent with good airflow, sterilized media, and early morning irrigation.

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Conclusion

Starting begonias from seed—especially pelleted begonia seeds—is one of the best ways to grow healthy, colorful plants for containers and baskets. With the right tray size, moisture levels, lighting, and disease prevention, you can enjoy lush begonias that thrive from spring through fall.

👉 Start your own today with Bulk Begonia Seeds or Smaller Packs of Begonia Seeds.

📌 Related blogs:

• When to Start Seeds Indoors by Zone (Complete Guide)

• The Ultimate Beginner’s Guide to Garden Seeds

• Garden Seeds for Every Season: What to Plant in Spring, Summer, and Fall