How to Grow Ten Weeks Stock Mammoth

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Ten Weeks Stock Mammoth

Matthiola incana

flower

Ten Weeks Stock Mammoth is a classic ornamental flowering plant prized for its tall spikes of densely packed, fragrant blooms in shades of pink, purple, red, white, and lavender. Known for its rapid growth and abundant flowering, it typically blooms within 10 weeks of sowing, making it ideal for quick garden color and cut flowers. The Mammoth variety is a large-flowered, double-blooming selection that produces particularly showy flower spikes.

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Example Ten Weeks Stock Mammoth timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Ten Weeks Stock Mammoth

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. First Ten Weeks Stock Mammoth blooms

    Around Jun 16

    ≈ 60 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Ten Weeks Stock Mammoth dates for your own zip code.

Growing Conditions

☀️
Sun: Full sun, 6-8 hours daily (tolerates light afternoon shade in hot climates)
💧
Water: Keep soil consistently moist but not waterlogged; water at soil level to avoid wetting foliage and reducing disease risk. Reduce watering in cool weather.
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Spacing: 9-12 inches apart inches
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Days to maturity: 60-80 days from sowing to first flowers
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Planting depth: Press seeds lightly into soil surface or cover with 1/8 inch of fine soil; seeds need light to germinate

Soil

Type: Well-draining fertile loamy soil
pH: 6.0-7.0
Amendments:
Compost Aged manure Perlite for drainage Balanced fertilizer (5-10-10)

Growing Zones

Find your zone →

Thrives in zones 2-10 as a cool-season annual; best flowering in zones 2-8 with cooler spring temperatures

2a 2b 3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b

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Growth Stages

1

Germination & Seedling

2-3 weeks

Seeds sprout in 7-14 days at 60-70°F. Cotyledons emerge followed by true leaves. Seedlings are delicate and small.

Keep soil moist but not soggy; provide bright light and cool temperatures; thin to proper spacing to prevent damping off. Avoid high humidity and poor air circulation.

2

Vegetative Growth

3-4 weeks

Plant develops a dense rosette of lance-shaped, blue-green foliage with sturdy stems elongating upward. Roots establish and plants gain vigor.

Maintain consistent moisture; apply balanced fertilizer every 2 weeks; ensure good air circulation. Pinch growing tips when 6 inches tall to encourage branching (optional).

3

Flower Bud Formation & Budding

2-3 weeks

A central flower spike forms at the stem apex with dense clusters of tiny flower buds tightly packed along the spike. Multiple side spikes may also develop.

Continue regular watering and fertilizing; reduce nitrogen slightly in favor of phosphorus to promote flowering. Keep temperatures cool for best bud development.

4

Flowering

4-8 weeks

Buds open progressively from bottom to top along the spike, revealing large double flowers in full color. Mammoth varieties produce particularly full, multi-petaled blooms on long, sturdy stems.

Water consistently; deadhead spent flowers to encourage continued blooming and prevent self-seeding. Apply low-nitrogen fertilizer to extend flowering. Cool nights prolong bloom period.

5

Seed Set & Decline

2-3 weeks

After pollination, flowers fade and pods form. In hot weather or as photoperiod lengthens, flowering slows and plants may decline.

Remove dead flowers to prevent seed set if prolonging bloom is desired. In regions with hot summers, plan succession plantings for continuous color. Let some flowers set seed to collect for next season if desired.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Brassicas (cabbage, broccoli, kale) Other Matthiola species (to prevent cross-contamination) Heavy shade from tall plants

Common Pests

  • Use row covers on young plants; handpick caterpillars; apply Bacillus thuringiensis (Bt) if infestation occurs

  • Apply neem oil or insecticidal soap; use reflective mulch; encourage natural predators

  • Spray with strong water jet; apply insecticidal soap or neem oil; encourage ladybugs and parasitic wasps

  • Improve air circulation; avoid overhead watering; apply sulfur dust or neem oil at first sign of white coating on leaves

  • Ensure well-draining soil; avoid overwatering; remove and destroy infected plants; apply fungicide if soil-borne disease suspected

Uses

🍳

Edible Flowers

Culinary

Stock flowers are edible and can garnish salads, desserts, and cocktails, offering a mild, slightly sweet flavor with a delicate texture. [source]

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Cut Flowers & Arrangements

Household

Tall, densely flowered spikes make Stock ideal for cutting gardens, floral arrangements, and wedding bouquets. Flowers last 1-2 weeks in a vase with proper care. [source]

🏠

Fragrance

Household

Stock flowers emit a sweet, clove-like fragrance that intensifies in cool, moist conditions. Popular in Victorian gardens for their perfume. [source]

🦋

Pollinator Support

Wildlife

Stock flowers attract bees, butterflies, and other pollinators, providing valuable nectar and pollen sources, especially in spring when other flowers are scarce. [source]

🎨

Dried Flowers

Craft

Stock flowers dry well and retain color, making them suitable for dried arrangements, pressed flowers, and craft projects. [source]

Harvest Tips

Cut flower spikes in early morning when buds on lower portion are open but upper buds still closed for longest vase life (7-14 days). Use a sharp knife to cut stems at an angle. Remove lower foliage below waterline. Re-cut stems every 2-3 days and change water frequently. Pinching off side shoots and deadheading encourages more blooms on garden plants.

Fun Facts

  • 🌱 The 'Ten Weeks' name refers to the remarkably fast time from seed to bloom—typically 60-80 days—making it one of the quickest-flowering ornamental plants available.
  • 🌱 Stock flowers were beloved in Victorian gardens and are featured in numerous historical garden paintings and texts; they remain popular in cutting gardens today.
  • 🌱 The Mammoth variety can produce flower spikes 12-24 inches long densely packed with blooms, and some flowers are double-flowered (with extra petals), making them exceptionally showy compared to wild single-flowered forms.

Gardening Terms

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