Home & Garden

This robust flower will give your garden beautiful blooms — like clockwork

Fortnight lily, a plant native to South Africa, produces large, showy flowers at roughly two-week intervals.
Fortnight lily, a plant native to South Africa, produces large, showy flowers at roughly two-week intervals.

Fortnight lily

Dietes grandiflora

Planting areas: USDA Zones 8a to 11

Size: Up to 4 feet tall and 3 feet wide

Bloom season: Spring, summer and fall. In milder areas may bloom into winter.

Exposure: Full sun to partial shade.

Water needs: Established plants are drought tolerant but bloom more freely with regular watering.

Snapshot: This South African native is a popular choice in California gardens because of its colorful flowers and suitability to a variety of landscape situations.

A member of the iris family, this plant produces large, showy white flowers with violet and yellow markings. Blooms seem to come at two-week intervals, hence its common name, fortnight lily.

Each blossom lasts only one day but is quickly replaced by another one.

Flower cycles occur on the same stalk. Breaking off forming seed pods increases flower production and minimizes the spread of unwanted volunteer plants.

Flowers are followed by 2-inch-long green capsules containing very dark brown seeds that are dispersed when the capsule splits open.

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Fortnight lily grows almost anywhere when planted in rich, well-drained soil. It can survive neglect and minimal water, but foliage quality and flower production suffer when conditions become too hot and dry.

The plant is also frost hardy, tolerating temperatures down to 25 degrees Fahrenheit.

Fortnight lilies are popular for en masse plantings and as accent plants in gardens, around swimming pools, along walkways and in containers. They are equally at home in both lush landscapes and low-water gardens.

Growth patterns may be more robust than expected, causing them to quickly outgrow containers or small planting areas.

Overgrown clumps do best when divided every four to five years after flowering in the autumn or winter. Split clumps with a fork and pull the divisions into smaller pieces with your hands. Make sure each piece has a good root system and several new shoots.

Discard old, woody or dead portions of the plant. New, smaller plants may be replanted in the same area or in another location. Firm the soil lightly after planting and water thoroughly.

Got a gardening question?

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