How to Grow Red Top

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Red Top

Agrostis gigantea

grass

Red Top is a perennial cool-season grass known for its fine texture and reddish-purple panicles that appear during flowering. It's commonly used in pasture mixes, hay production, and erosion control due to its adaptability and deep root system. The plant is valued for its tolerance of wet soils and poor drainage conditions.

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Example Red Top timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Red Top

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Red Top

    Around Jun 16

    ≈ 60 days after planting

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

Growing Conditions

☀️
Sun: Full sun to part shade, minimum 4 hours of direct sunlight daily
💧
Water: Moderate to high water needs; tolerates wet conditions better than most grasses. Requires consistent moisture during establishment. Drought-tolerant once established but prefers adequate moisture.
📏
Spacing: Not applicable for seeding; use 40-50 lbs per acre for pasture or erosion control inches
📅
Days to maturity: 60-90 days for seedling establishment; reaches productive stage in one growing season
🌱
Planting depth: Seed should be surface-sown or very shallow (less than 1/4 inch) as light is required for germination

Soil

Type: Tolerates a wide range of soil types; performs well in wet, poorly drained, and acidic soils
pH: 5.0-7.5
Amendments:
Lime (if pH is below 5.0) Compost or organic matter for moisture retention in sandy soils

Growing Zones

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Thrives in zones 2-8, with best performance in cooler northern regions

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

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Growth Stages

1

Germination

7-14 days

Tiny seedlings with initial leaf emergence. Seeds germinate quickly in cool, moist conditions.

Keep soil consistently moist but not waterlogged. Provide light exposure for germination. Maintain cool temperatures (55-65°F ideal).

2

Seedling Establishment

3-4 weeks

Young plants developing their root system and producing 3-5 true leaves. Fine texture becoming visible.

Maintain moisture without causing fungal issues. Protect from heavy foot traffic. Light fertilizer with balanced NPK (10-10-10) can help.

3

Vegetative Growth

4-8 weeks

Grass tillers are developing, creating denser coverage. Plant height increases to 6-12 inches with fine, narrow leaf blades.

Mow when reaching 3-4 inches tall; remove no more than 1/3 of blade height per cutting. Continue regular watering. Light nitrogen applications promote tillering.

4

Flowering

3-4 weeks

Reddish-purple panicles (seed heads) emerge on stems 12-24 inches tall, creating the distinctive red appearance.

Cease nitrogen fertilization to discourage excessive vegetative growth during flowering. Reduce mowing if preserving for hay. Adequate moisture supports seed development.

5

Seed Maturation and Dormancy

4-8 weeks

Seeds mature and develop full color. Plant enters dormancy period in late fall/winter in cooler zones.

Allow seed heads to mature if collecting seed. Reduce watering as plant naturally enters dormancy. Spring growth resumes as temperatures warm.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Allelopathic species that inhibit grass growth Dense shade-producing trees that reduce light availability

Common Pests

  • Monitor for damage; apply insecticidal soap or spinosad if populations warrant. Natural enemies like parasitic wasps help control populations.

  • Less common in Red Top but possible in drier conditions. Use resistant varieties and maintain adequate moisture. Neem oil sprays if severe.

  • Apply insecticides at larval stage if damage is significant. Maintain healthy plant vigor through proper water and nutrition.

  • Improve drainage and air circulation. Avoid excessive nitrogen fertilization. Apply fungicides if severe. Reduce thatch buildup.

Uses

🍳

Livestock Feed

Culinary

Red Top is widely used in pasture mixes and hay production for cattle, sheep, and horses. It provides good nutritional value and palatability when harvested at appropriate growth stages. [source]

🏠

Erosion Control and Soil Stabilization

Household

The deep root system and quick establishment make Red Top excellent for stabilizing embankments, stream banks, and erosion-prone areas. It's commonly used in reclamation projects and conservation areas. [source]

🦋

Habitat and Wildlife Food

Wildlife

Red Top provides cover and food sources for wildlife including birds, insects, and small mammals. The seed heads are nutritious for granivorous birds. [source]

🏠

Turf and Ornamental Uses

Household

While not commonly used for fine turf in lawns, Red Top can be part of shade-tolerant grass mixes and is valued for its fine texture and disease resistance in certain climate zones. [source]

🎨

Decorative Dried Arrangements

Craft

The distinctive reddish-purple panicles are attractive in dried flower arrangements and can be harvested for decorative purposes. [source]

Harvest Tips

Red Top is typically harvested as hay or pasture forage, not as a seed crop for most growers. For hay: cut at boot stage or early flower for best nutritional value. For seed production: allow plants to fully mature, then cut and dry before threshing. Pasture grazing should begin when plants reach 3-4 inches and be rotated before grazing below 1 inch.

Fun Facts

  • 🌱 Red Top gets its common name from the distinctive reddish-purple color of its seed panicles, which appear during flowering and give the plant its most striking appearance.
  • 🌱 Despite being called 'Red Top,' it's also known as Herd's Grass and was historically one of the most important pasture grasses in North American agriculture before more modern cultivars were developed.
  • 🌱 Red Top has an exceptional ability to thrive in wet, waterlogged soils where many other grasses struggle, making it invaluable for poorly drained agricultural land and wetland restoration projects.

Gardening Terms

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