Clarkia

Growing in Pots, Balconies & Indoors

Clarkia is a sun-loving hardy annual grown for its papery flowers – lovely in outdoor pots and window boxes, but not a houseplant. Indoors, without strong light, it stretches and grows leggy, and the grower confirms it is not suited to life as a houseplant.

Quick Details

• Container Size: A medium pot or window box (roughly 2-5 L) with free drainage suits a few plants; being an annual it never needs potting up
• Indoor Suitability: Not a houseplant; at most a bright sill for raising seedlings
• Best Spot: Full sun, or light shade in hot climates (fewer flowers but a longer season)
• Soil & Drainage: Light, free-draining mix that is not too rich – over-feeding gives leaf at the expense of flower
• Watering in Pots: A small-to-average amount; keep just moist and never waterlogged – pots dry faster than open ground

Indoors & On the Windowsill

• Not a houseplant: The grower says it will not grow indoors as a houseplant; in a room it becomes drawn and flowers poorly.
• Windowsill: A very sunny sill is useful for starting seedlings, but for real flowering it needs to move outdoors into full light.
• Season: Being an annual there is nothing to overwinter – sow a fresh batch each growing season.

On a Balcony or Patio

• Excellent container annual: It is at its best in pots, troughs and window boxes in full sun; deadhead spent blooms to keep it flowering, and shelter taller stems from strong wind.
• Heat & water: Reflected heat from walls and railings dries pots quickly – check moisture often in warm weather, but avoid keeping the mix soggy.

Choosing the Pot, Soil & Long-Term Care

• Pot & drainage: Any pot or window box with strong drainage holes; skip a standing saucer to avoid root rot.
• Potting mix: A light, free-draining mix; keep it on the lean side, as rich soil produces foliage rather than flowers.
• Feeding: Feed sparingly – a light, balanced feed is plenty; too much nitrogen suppresses blooming.

Bloom & Flower Guide

Quick Details

• Bloom Season: Spring into summer
• Time to First Bloom: In its first year, roughly two to three months after sowing
• Flower Appearance: Four-petalled flowers in pink, purple, white, orange, red or bicolours
• Edibility: Grown as an ornamental and cut flower

Detailed Blooming Overview

Clarkia is an easy hardy annual that flowers freely from spring into summer, sending up slender stems lined with satiny four-petalled blooms. It flowers best in the cooler part of the season and makes a long-lasting cut flower.

Flower Characteristics

• Flowers have four petals and come in pink, purple, white, orange, red or more than one colour.
• Carried along upright stems, opening in succession up the stem.

Bloom Care & Thinning

• Prolonging the display: deadhead spent blooms regularly to keep new flowers coming.
• Position: a sunny spot and not-too-rich soil give the sturdiest, most floriferous plants.