Amaryllis (Hippeastrum) Grow Guide – Botanical Overview

Family: Amaryllidaceae
Genus: Hippeastrum
Origin: Tropical and subtropical regions of Central and South America
Common Name: Amaryllis (UK horticulture)
Type: Bulbous perennial

Botanical Description

• Bulb: Large, tunicate, ovoid, 10–15 cm in diameter; storage organ for carbohydrates and nutrients.
• Leaves: Strap-shaped, glossy green, arising after flower emergence in many cultivars.
• Flowers: Solitary or in umbels, funnel-shaped, 12–20 cm long; six tepals often vividly colored with stripes or patterns.
• Reproductive Structures:
  • Male (Stamens): Filament + anther, pollen-producing.
  • Female (Pistil): Stigma (receptive surface), style (elongated stalk), ovary (inferior, trilocular), containing ovules.

Cultivation Requirements

Light

• Indoors: Bright, indirect sunlight. South- or west-facing windows ideal.
• Outdoors (summer): Full sun to partial shade. Protect from scorching midday sun in hot regions.

Temperature / Hardiness

• Optimal growth: 18–24°C during active growth.
• Flowering: Slightly cooler nights (15–18°C) promote bud formation.
• Hardiness: USDA zones 9–11 (tender bulb).
• UK cultivation: Typically grown in pots, overwinter indoors at 10–15°C.

Soil

• Type: Well-draining, fertile loam or general-purpose potting mix.
• Composition: Incorporate sand or grit to improve drainage. Avoid heavy clay or waterlogged soils.
• pH: Neutral to slightly acidic (6.0–7.0).

Watering

• Keep moderately moist during active growth.
• Reduce watering after flowering as bulb enters dormancy.
• Avoid wetting the crown to prevent rot.

Fertilization

• Active growth (spring-summer): Balanced, water-soluble fertiliser (NPK 10:10:10) every 2–3 weeks.
• Bulb storage: Do not fertilise during dormancy.

Propagation

• Seed: Slow, 3–5 years to flowering.
• Offsets (bulblets): Faster method, clone parent traits.

Dormancy

• Essential for flowering the following season.
• Leaves naturally die back 6–8 weeks post-flowering.
• Store bulbs dry and cool (10–15°C) for 8–12 weeks.

Month-by-Month Cultivation Guide (UK / Pot-Grown)

Pests and Diseases

• Common pests: Aphids, spider mites, mealybugs.
• Fungal issues: Bulb rot from waterlogging; red blotch (Stagonospora curtisii).
• Control: Good air circulation, well-draining media, inspect bulbs before storage.

January

• Most amaryllis are in flower now.
• Keep plants in a bright, warm room (18–22°C).
• Water sparingly but regularly – don’t let the compost dry out completely.
• Turn the pot every few days so the flower stem grows straight.
• Stake tall flower stems if needed.

February

• Flowers begin to fade.
• Deadhead spent blooms, but do not cut the stem until it yellows.
• Continue watering lightly.
• Keep in good light to support the leaves forming next.

March

• Flower stems die back naturally – now you can cut them off.
• Leaves should be growing strongly.
• Start feeding every 2 weeks with a balanced liquid fertiliser.
• Water more freely as growth increases.

April

• Strong leaf growth.
• Continue feeding fortnightly.
• If rootbound, repot after flowering into a pot only slightly larger.
• Use free-draining compost (multi-purpose with added grit).

May

• Once frost risk has passed, pots can go outside.
• Place in a sheltered, sunny spot.
• Water regularly and feed every 2 weeks.
• This is when the bulb rebuilds energy for next year’s flowers.

June

• Peak leaf growth.
• Keep watering and feeding.
• Remove weeds and ensure good airflow if outdoors.
• Avoid waterlogging – bulbs hate sitting wet.

July

• Continue as June.
• Leaves should be lush and strap-like.
• A lack of feeding now = no flowers next year.

August

• Gradually reduce feeding towards the end of the month.
• Keep watering but slightly less often.
• Bulb is finishing its energy storage phase.

September

• Begin rest period preparation.
• Stop feeding completely.
• Reduce watering significantly.
• Move pots under cover if outdoors.

October

• Leaves yellow and die back.
• Stop watering.
• Cut leaves off once fully yellow.
• Store bulbs cool and dry (10–15°C), in their pots or lifted.

November

• Bulbs remain dormant.
• Keep dry and cool.
• No watering at all.

December

• Time to restart growth for winter flowers.
• Move bulb to warmth and light.
• Start watering lightly.
• Flower buds usually appear before leaves.

Quick Growing Tips

• Pot size: snug pots encourage flowering.
• Light: bright light is essential, especially after flowering.
• Feeding: the most common mistake is not feeding enough after flowering.
• Botanical note: Amaryllis sold in the UK are usually Hippeastrum, not true Amaryllis belladonna.