How to Grow Begonia Senator Series

Begonia Senator Series

Begonia × semperflorens-cultorum 'Senator Series'

flower

The Senator Series is a group of compact wax begonias bred for uniform growth, dense flowering, and excellent garden performance. These tender perennials are grown as annuals and produce continuous blooms throughout the season in shades of red, pink, and white. They are ideal for bedding, containers, and hanging baskets due to their bushy, mounding habit.

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Example Begonia Senator Series timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Begonia Senator Series

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. First Begonia Senator Series blooms

    Around Jun 6

    ≈ 50 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Begonia Senator Series dates for your own zip code.

Growing Conditions

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Sun: Partial shade to partial sun, 4-6 hours of indirect light daily. Tolerates more sun in cooler climates; afternoon shade beneficial in hot regions.
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Water: Keep soil consistently moist but not waterlogged. Water when top inch of soil feels dry. Begonias prefer humidity; water at soil level to avoid leaf spotting. Reduce watering in winter dormancy.
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Spacing: 8-12 inches
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Days to maturity: 50-70 days from transplant to first significant bloom
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Planting depth: Sow seeds on surface (do not cover; they need light to germinate). Transplants should be set at same depth as in containers.

Soil

Type: Well-draining, light, fertile loamy soil
pH: 6.0-6.5
Amendments:
Peat moss or coco coir Perlite or vermiculite for drainage Balanced slow-release fertilizer

Growing Zones

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Grown as annuals in zones 2-11; perennial in zones 10-11. Best performance in zones 5-10 as a tender annual.

10a 10b 11a 11b

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Growth Stages

1

Seed to Seedling

2-3 weeks

Tiny seeds germinate on soil surface under bright, indirect light. First true leaves appear within 1-2 weeks.

Keep soil moist but not soggy. Maintain 70-75°F temperature. Provide bright, indirect light. Use bottom heat (65-70°F) to encourage germination.

2

Seedling to Young Plant

3-4 weeks

Plant develops 2-4 true leaves and strengthens root system. Growth is slow initially but steadily accelerates.

Maintain consistent moisture and bright indirect light. Begin light fertilizing at half strength weekly. Thin seedlings or pot up to prevent crowding.

3

Vegetative Growth

4-5 weeks

Plant develops dense foliage and bushy form. Leaves are waxy, dark green with bronze or red tones depending on variety. Plant becomes increasingly compact.

Maintain moisture and warmth (65-72°F). Fertilize weekly with balanced fertilizer. Pinch back growing tips at 4-6 weeks to encourage branching and bushiness.

4

Flowering

8-12+ weeks (until frost or end of growing season)

Small waxy flowers appear continuously in clusters above the foliage. Flowers range from deep red to pink to white. Plant reaches mature size and maintains dense blooming.

Deadhead spent flowers to encourage continuous bloom. Continue regular fertilizing and consistent watering. Provide humidity with morning watering or misting (avoid wetting foliage in evening).

5

Mature Plant/Decline

Ongoing through season

Plant reaches full size and may become leggy or reduced in vigor as temperatures drop in fall. Flowering continues until frost.

Pinch back leggy growth in midsummer if needed to rejuvenate. Reduce watering and fertilizing as days shorten. Bring indoors before first frost if overwintering.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Dense shade plants that create excessive moisture Plants requiring dry conditions (e.g., sedums, santolina) Very tall plants that shade out the begonias

Common Pests

  • Increase humidity, spray with water, use neem oil or insecticidal soap if severe. Ensure good air circulation.

  • Remove with cotton swab dipped in rubbing alcohol. Spray with insecticidal soap or neem oil. Isolate infested plants.

  • Yellow sticky traps, strong water spray to dislodge, neem oil, or insecticidal soap. Increase air circulation.

  • Improve air circulation, reduce humidity, avoid wetting foliage. Use sulfur dust or fungicide if severe. Remove affected leaves.

  • Reduce humidity, improve air circulation, remove dead flowers and leaves. Fungicide may be needed in humid conditions.

Uses

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Edible Flowers

Culinary

Begonia flowers are edible with a subtle tart, citrus-like flavor and are used as garnishes in salads and desserts. They add visual appeal and a delicate taste to culinary presentations. [source]

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Garden Bedding & Containers

Household

The Senator Series is specifically bred for uniform, dense bedding displays and container growing. Its compact, mounding habit makes it ideal for borders, window boxes, and hanging baskets with continuous color. [source]

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Indoor Houseplants

Household

Senator Series begonias can be grown indoors year-round near bright, indirect light windows or under grow lights. They make attractive container plants for homes and offices. [source]

🦋

Pollinator Support

Wildlife

The continuous flowers attract bees and other pollinating insects, making begonias valuable for supporting local pollinator populations in gardens and landscapes. [source]

💊

Traditional Uses

Medicinal

Begonias have been used in traditional medicine in various cultures to treat skin conditions and inflammation, though scientific evidence is limited. Modern use is primarily ornamental. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

Begonias are ornamental flowers meant for display rather than harvesting, but you can cut stems with flower clusters for indoor arrangements. Cut in morning when stems are turgid. Pinching back growing tips throughout the season encourages bushier growth and more flowers.

Fun Facts

  • 🌱 The Senator Series was bred specifically for commercial bedding production, with emphasis on uniform height, consistent flowering, and disease resistance—making it one of the most reliable begonia lines for mass plantings.
  • 🌱 Begonia seeds are extremely tiny (finer than dust) and require light to germinate; they are never covered when sown. A single seed pod can contain thousands of these microscopic seeds.
  • 🌱 Wax begonias earned their name from the waxy, succulent texture of their leaves and stems, which helps them retain moisture and gives them a distinctive glossy appearance.

Gardening Terms

New to gardening? Learn about terms used in this guide:

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