Triteleia - Brodiaea: Planting, Growing and Caring

Botany and description

Triteleias are bulbous plants from the Asparagaceae family (according to the latest phylogenetic classification) and the Brodiaeoid subfamily. In fact, it’s not uncommon to still encounter the genus name Brodiaea instead of Triteleia in literature or commerce. Beware of confusion!

The genus name Triteleia comes from Greek: from “Treis” (three) and “Teleios” (perfect), referring to the flower’s regular star shape. In California, Triteleia laxa is nicknamed “Ithuriel’s Spear”, one of the angels in “Paradise Lost”, a poem by John Milton (1667).

Triteleia uniflora, botanical plate, circa 1850

The various Triteleia species are native to dry prairies and woodlands of the western United States.

The Triteleia genus includes about twenty species, the most well-known and cultivated being Triteleia laxa.

To be precise, triteleias are actually cormous plants. Corms are swollen underground stem parts that serve as nutrient storage organs, resembling bulbs. This is why triteleias are classified as “bulbous” plants.

The deciduous foliage appears in spring, forming a clump of lanceolate leaves, slender, 20 to 30 cm long and green in colour. The leaves lie down and turn yellow, even drying out, as flowering begins. The plant completely disappears after flowering.

Flowering starts as early as May for Triteliea laxa and Triteleia ixoides, continuing until August for some varieties like Triteleia ‘Rudy’ or Triteleia ‘Queen Fabiola’. Each corm produces large umbels of about twenty blue, white (Triteleia ‘Silver Queen’), pink or even yellow flowers (in Triteleia ixoides). The tubular flowers open into star shapes and are borne on slender, rigid stems up to 50 cm tall. The flowers can be used in bouquets.

If conditions suit them, Triteleias naturalise easily, forming beautiful colonies over the years. They’re grown in rockeries, dry gardens and even containers.

Blue Triteleias laxa, with Triteleia ixioides top right

Our most beautiful varieties

Triteleia laxa

Triteleia laxa is a lesser-known bulbous plant, producing remarkable small star-shaped flowers with bold purple-blue stripes.

• Flowering time June, July
• Height at maturity 35 cm

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Triteleia laxa Queen Fabiola

Triteleia laxa 'Queen Fabiola' is one of the hardiest varieties. It blooms into a cloud of small sky-blue flowers striped with navy blue.

• Flowering time August, September
• Height at maturity 35 cm

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Triteleia Rudy

Triteleia 'Rudy' produces, in early summer, a profusion of small white star-shaped flowers with dark blue markings.

• Flowering time August, September
• Height at maturity 40 cm

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Triteleia laxa Silver Queen

Triteleia laxa 'Silver Queen' is an exceptionally refined and luminous variety, with white iridescent flowers displaying a lovely silvery sheen.

• Flowering time June, July
• Height at maturity 45 cm

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Triteleia Corrina

Triteleia 'Corinna' produces, in early summer, a cloud of small star-shaped flowers in a deep violet-blue hue.

• Flowering time August, September
• Height at maturity 25 cm

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Triteleia Aquarius

Triteleia 'Aquarius' blooms into a multitude of small, very double and intensely blue flowers, edged with midnight blue on the reverse.

• Flowering time July, August
• Height at maturity 40 cm

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Triteleia ixioides 'Starlight'

Triteleia ixioides 'Starlight' is the only variety in the genus to produce creamy yellow flowers. Earlier than others, it blooms as early as May.

• Flowering time June
• Height at maturity 30 cm

See the product sheet

Planting Triteleias

Where to Plant?

Triteleias should be planted in full sun or partial shade in the southern part of France. In cooler climates, ensure your triteleias are well protected from cold and wind: near a south-facing wall, for example.

The soil should be fertile but above all light and well-drained. The ground must remain moist during the growing season but dry during the dormant period in winter. Planting Triteleia corms directly in sand greatly improves the plant’s hardiness.

Triteleias look stunning when planted en masse

When to Plant

Triteleias can be planted in autumn (October), but spring is the best time: planting is best done between March and April.

How to Plant?

In the ground:

• Loosen the soil to a depth of about 10 cm;
• Add well-rotted compost, sand, or even some gravel to lighten the soil and improve drainage;
• Plant the corms (bulbs) at a depth of 10 cm, spacing them at about 20 corms per m²;
• Cover with mulch in winter to protect the corms from severe frosts.

In pots:

• Use a terracotta pot with drainage holes at the bottom;
• Fill it with a light substrate such as Mediterranean plant compost;
• Plant the corms (bulbs) at a depth of 10 cm;
• Triteleias in pots are more vulnerable to cold than those in the ground: only place the pot outside once all risk of frost has passed.

Maintenance

Maintenance is limited to watering during the growing season (when foliage appears) and only if the soil is dry. In pots, water every two days, always during the growing season.

During the dormancy phase, when the plant appears to have disappeared, the soil or substrate must remain dry.

If your triteleias are grown in pots, move them to a frost-free location during winter.

Note: during dormancy, when triteleias have completely disappeared underground, there is a risk of damaging the corms with tools. Remember to place markers to avoid this.

Triteleia uniflora

Diseases and Pests

Triteleias are not affected by any diseases or pests. The only thing they fear is winter moisture.

Propagation

By sowing

It is possible, though very time-consuming, to propagate your triteleias by sowing. Simply collect the ripe seeds in summer and sow them in a well-draining substrate (half sowing compost and half river sand) at a temperature around 15°C.

The first flowers will only appear after 4 years of cultivation. Impatient gardeners beware!

Or more quickly and easily…

Small corms develop around the planted triteleia corms. You can either leave them undisturbed to allow a carpet of triteleias to form, or dig slightly around the area to retrieve the small corms and relocate them elsewhere in spring.

Association

The issue with Triteleias is that their foliage becomes unsightly during flowering. We should therefore aim to conceal it with low-growing plants. However, these companion plants must thrive under the same growing conditions as our Triteleias: full sun, very well-drained soil, yet kept moist in summer.

What if we mixed different Triteleias? Blue, yellow, and white ones streaked with blue—such as the single Triteleia laxa (the species type) with violet-blue flowers, the strikingly original blue-and-white Triteleia ‘Rudy’, and the creamy-yellow Triteleia ixioides ‘Starlight’, which will contrast beautifully with the cool tones of the other two.

To complement them, let’s stick to blue and yellow hues with a few other perennials. For yellow-green foliage and blue flowers, try one or two Gentiana cruciata—a slightly finicky plant that also prefers well-drained soil and moisture during flowering. Staying with blue flowers, add a few Amsonia ‘Blue Ice’, whose star-shaped blue blooms will echo those of the Triteleias. The reliable Carex oshimensis ‘Evergold’ will enhance the blue flowers with its green foliage and broad cream stripe. Finally, a yellow-flowering groundcover like Helianthemum ‘Ben Fhada’ will serve as a perfect frame for the Triteleias’ blooms.

Triteleia ‘Rudy’, Triteleia ‘Starlight’, and Triteleia laxa beautifully paired with Gentiana cruciata, Carex oshimensis ‘Evergold’, Amsonia ‘Blue Ice’, and Helianthemum ‘Ben Fhada’