How to Grow Hermine Grashoff

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Hermine Grashoff

Pelargonium 'Hermine Grashoff'

flower

Hermine Grashoff is a distinctive ivy-leaf geranium (pelargonium) cultivar known for its striking double flowers in a unique salmon-pink or coral-red color with darker veining. This trailing or semi-climbing variety produces abundant blooms throughout the growing season and is prized for containers, baskets, and as a houseplant. It combines the vigorous growth habit of ivy-leaf geraniums with exceptionally showy, long-lasting flowers.

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Example Hermine Grashoff timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Hermine Grashoff

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. First Hermine Grashoff blooms

    Around Jun 16

    ≈ 60 days after planting

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

Growing Conditions

☀️
Sun: Full sun, 6-8 hours daily; tolerates partial shade but blooms best in full sun
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Water: Allow soil to dry between waterings; water thoroughly when top inch is dry. Reduce watering in winter. Avoid overwatering, which causes root rot. Water at soil level to keep foliage dry.
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Spacing: 12 inches
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Days to maturity: 60-90 days from rooted cuttings to first blooms
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Planting depth: Surface plant (seeds) or transplant at same depth as original pot; can be propagated easily from cuttings

Soil

Type: Well-draining loamy or sandy soil
pH: 6.0-6.8
Amendments:
Perlite or coarse sand for drainage Compost for organic matter Avoid heavy clay or moisture-retentive soil

Growing Zones

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Zones 9-11; can be grown outdoors year-round in warmer climates or as a tender perennial/houseplant elsewhere

9b 10a 10b 11a 11b

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Growth Stages

1

Cutting/Rooting

2-3 weeks

Young cutting with developing roots, typically 3-4 inches long with 2-3 leaf nodes visible

Keep in humid conditions (70% humidity ideal). Use well-draining propagation mix. Provide bright, indirect light. Avoid direct sun and waterlogging.

2

Establishment

3-4 weeks

Rooted cutting developing true leaves and establishing a small root system

Gradually acclimate to brighter light. Begin light fertilizing every 2 weeks at half strength. Pinch growing tips to encourage branching.

3

Vegetative Growth

4-6 weeks

Plant developing bushy, trailing growth with abundant green, ivy-shaped foliage

Full sun exposure. Water when dry. Regular balanced or slightly low-nitrogen fertilizer every 2 weeks. Pinch tips for fuller shape. Provide support/trellis if desired.

4

Flowering

8+ weeks (blooms continuously in season)

Abundant clusters of double coral-pink to salmon-red flowers with darker veining appear throughout stems

Maintain full sun and good air circulation. Switch to higher-phosphorus fertilizer to support blooming. Deadhead spent flowers regularly to encourage continuous blooms.

5

Winter/Dormancy (if applicable)

3-4 months

Reduced growth and flowering in cooler temperatures; plant may drop some leaves

Reduce watering significantly. Provide cooler conditions (50-60°F ideal). Minimal fertilizing. Prune lightly if desired. This rest period improves spring vigor.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Brassicas (prone to similar whitefly issues) Plants requiring consistently moist soil Heavy feeders that deplete soil

Common Pests

  • Spray with insecticidal soap or neem oil every 7-10 days. Maintain good air circulation. Use yellow sticky traps. Remove heavily infested leaves.

  • Increase humidity with regular misting. Spray with water or insecticidal soap. Apply neem oil if severe. Isolate infested plants.

  • Remove with rubbing alcohol on cotton swabs. Spray with insecticidal soap or horticultural oil. Isolate plant and monitor closely.

  • Allow soil surface to dry between waterings. Use yellow sticky traps. Apply sand layer on top of soil. Use beneficial nematodes if severe.

  • Improve air circulation. Remove dead/damaged foliage. Reduce humidity. Avoid wetting foliage. Apply fungicide if necessary.

Uses

🍳

Edible Flowers

Culinary

The flowers, though not commonly eaten, are technically edible and can garnish desserts or salads for ornamental appeal. Pelargonium flowers have a slightly floral, peppery taste. [source]

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Container & Hanging Basket Display

Household

The trailing growth habit and prolific double blooms make this cultivar ideal for hanging baskets, mixed containers, window boxes, and as a trailing accent in container gardens. Excellent for vertical gardening. [source]

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Houseplant & Indoor Decor

Household

Grows well as a potted houseplant on bright windowsills or under grow lights. Long blooming season provides continuous color indoors, and it's easy to propagate for sharing. [source]

💊

Traditional Herbal Use

Medicinal

Pelargonium species have been used in traditional medicine; geranium leaf tea is sometimes used for astringent properties, though scientific evidence is limited. Always consult a professional before medicinal use. [source]

🦋

Pollinator Support

Wildlife

Abundant flowers attract bees, butterflies, and hoverflies, supporting local pollinator populations and beneficial insects in gardens. [source]

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

Harvest Tips

Not typically harvested for fruit/seeds like vegetables. Deadhead spent flower clusters regularly (pinch off after blooming) to encourage continuous flowering throughout the season. Can harvest cuttings for propagation year-round; best success with 3-4 inch stem cuttings taken in spring or early summer. Take cuttings just below a leaf node.

Fun Facts

  • 🌱 Hermine Grashoff is a hybrid ivy-leaf geranium with genetics tracing back to South African Pelargonium peltatum species, renowned for producing some of the most intensely colored double flowers in the pelargonium family.
  • 🌱 Unlike most geraniums, this cultivar can be propagated easily from soft cuttings without rooting hormone, rooting successfully in just 2-3 weeks under proper conditions.
  • 🌱 The name 'Hermine Grashoff' honors a German geranium breeder, reflecting the cultivar's European origins and the significant role German horticulturists played in developing modern pelargonium varieties.

Gardening Terms

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