How to Grow Tall Broomcorn

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Tall Broomcorn

Sorghum bicolor var. technicum

grass

Tall broomcorn is a grain sorghum variety cultivated primarily for its stiff, naturally bristly seed heads used to make brooms and brushes. It can reach heights of 8-14 feet with robust stalks and produces dense, upright panicles of seeds. This heirloom crop is valued for both its practical fiber production and ornamental appeal.

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Example Tall Broomcorn timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Tall Broomcorn

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Tall Broomcorn

    Around Aug 15

    ≈ 120 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Tall Broomcorn dates for your own zip code.

Growing Conditions

☀️
Sun: Full sun, minimum 8 hours daily; 10+ hours optimal for tall growth
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Water: Moderate watering; drought-tolerant once established. Water deeply 1-2 times weekly during germination and early growth. Reduce watering after boot stage. Prefers 20-30 inches annual rainfall.
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Spacing: 12 inches
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Days to maturity: 120-150 days
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Planting depth: 1-1.5 inches

Soil

Type: Well-draining loamy to sandy soil
pH: 5.5-7.5
Amendments:
Compost or well-rotted manure Balanced NPK fertilizer (10-10-10 or similar) Gypsum if soil is compacted

Growing Zones

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Thrives in zones 6-9; warm-season annual requiring 120+ frost-free days

5b 6a 6b 7a 7b 8a 8b 9a 9b 10a

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Growth Stages

1

Seedling

2-3 weeks

Germination occurs within 5-10 days. Tall, narrow seedlings with 2-3 leaves emerge. Plants are delicate and vulnerable to birds and wind.

Protect from birds with netting or scare devices. Keep soil consistently moist but not waterlogged. Thin seedlings to proper spacing early.

2

Vegetative Growth

6-8 weeks

Plants develop multiple leaves and a strong root system. Height increases rapidly to 3-6 feet. Stems thicken and become more resilient. No visible reproductive structures yet.

Apply balanced fertilizer at 4-6 weeks. Support with stakes if in windy locations. Monitor for early pest activity (aphids, grasshoppers). Water consistently.

3

Boot to Heading

3-4 weeks

Panicles form and push through leaf sheaths. Plants reach near-final height (8-14 feet). Transition from vegetative to reproductive phase. Flag leaf is fully expanded.

Reduce nitrogen fertilizer to prevent lodging. Provide sturdy support stakes, especially for tall cultivars. Water deeply but infrequently; drought stress at this stage improves bristle quality.

4

Flowering and Seed Development

3-4 weeks

Panicles expand with visible flowers producing pollen. Seed heads darken and seeds fill rapidly. Bristle quality develops during this critical phase.

Minimal watering now unless severe drought occurs. Do not apply nitrogen—it reduces bristle stiffness. Monitor for midge damage on developing seeds. Allow drying to begin naturally.

5

Maturity and Harvest Readiness

2-3 weeks

Seed heads become fully dry and brittle with characteristic stiff bristles. Plant stems turn brown and seeds harden completely. Ready for cutting or harvesting.

Harvest when moisture content of seeds drops below 20% and bristles are completely rigid. Cut panicles carefully to avoid shattering. Cure in dry, airy location for 2-4 weeks before processing.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Sudan grass Other sorghum varieties (cross-pollination risk) Corn (pest and disease competition) Legumes in heavy cultivation (nitrogen depletion)

Common Pests

  • Plant early-maturing varieties; remove crop residue; release parasitic wasps; monitor with sticky traps

  • Hand-pick on small plantings; use Bacillus thuringiensis (Bt); encourage natural predators

  • Row covers on young plants; vacuum collection; insecticidal soap; minimize bare ground nearby

  • Plant resistant varieties; remove nearby grass hosts; beneficial nematodes; insecticidal soap

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

  • Netting; reflective tape; scarecrows; noise-makers; plant densely to reduce individual plant damage

Uses

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Traditional Broom Making

Household

The primary use of tall broomcorn is crafting natural brooms and brushes. The rigid, naturally bristly panicles are processed into whisk brooms, hand brooms, and decorative broom corn bundles without synthetic additives. [source]

🎨

Ornamental and Dried Arrangements

Craft

The dramatic tall stalks and seed heads are valued in dried flower arrangements, floral design, and rustic home décor. The natural tan and brown colors add texture to autumn and harvest-themed displays. [source]

🍳

Grain and Seed Use

Culinary

Like other sorghum varieties, broomcorn seeds are nutritious and can be used for human consumption as a grain, ground into flour, or popped like popcorn. Seeds can also feed livestock and poultry. [source]

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Wildlife Habitat and Feed

Wildlife

The tall stalks provide shelter for birds and beneficial insects, while the abundant seeds feed wild birds, pollinators, and support biodiversity in agricultural settings. [source]

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Natural Sweeping Tools and Bristle Products

Household

Beyond traditional brooms, processed broomcorn bristles are used in brushes, whisk brooms, fiber products, and renewable household cleaning tools that are biodegradable and sustainable. [source]

Harvest Tips

Harvest panicles when seed moisture is 15-20% and bristles are completely dry and brittle—typically 4-6 weeks after flowering. Cut panicles at the base with a sharp knife or sickle, leaving 12-18 inches of stem. Cure harvested panicles in a dry, ventilated location (attic, barn, or shed) for 2-4 weeks, ensuring good air circulation to prevent mold. Bristles should snap cleanly when folded. Process by removing seeds and trimming bristles to uniform length (24-30 inches is traditional). Store in cool, dry conditions away from moisture.

Fun Facts

  • 🌱 Tall broomcorn can reach extraordinary heights of 12-14 feet in ideal conditions, making it one of the tallest grain crops and creating an impressive, dramatic presence in the garden or field.
  • 🌱 The bristles require no chemical treatment or processing to achieve their natural stiffness—the plant's genetics create the rigid fibers naturally, making it a truly sustainable craft material with minimal environmental impact.
  • 🌱 Broomcorn was commercially widespread in the United States during the 19th and early 20th centuries, with entire regions like central Illinois dedicated to its cultivation, but modern synthetic broom bristles have reduced demand, making homegrown heirloom varieties increasingly rare and valued by sustainability-focused gardeners.

Gardening Terms

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