The species Ipheion uniflorum, also known as the spring star or spring star flower, is a spring bloomer that is not yet well known in German gardens. However, this should urgently change, because the delicate flower with its distinctive, star-shaped flowers has a whole range of plus points to offer. Read how best to establish the single-flowered spring star in the garden.
What are the special features of the star flower (Ipheion uniflorum)?
The star flower (Ipheion uniflorum) is an attractive spring bloomer with star-shaped flowers in various colors. It prefers a sunny to partially shaded location, well-drained soil and is hardy. Starflowers can be planted in beds, rock gardens or in pots and offer a long flowering period from March to May.
Origin and distribution
Various species are available commercially under the name “star flower”. This article is about the single-flowered spring star (bot. Ipheion uniflorum or, according to the new scientific classification, Tristagma uniflorum), a species of onion flower that belongs to the subfamily of the allium family (bot. Allioideae).
The pretty spring bloomer has its home in the temperate climatic zones of Uruguay and Argentina, where it is abundant in the grassy steppes of the Andes. There are also larger natural occurrences in France and the south of Great Britain, as the species was naturalized there a few years ago through the naturalization of garden forms.
Usage
The star flower is a spring bloomer that looks good both in the bed and as a potted plant on the balcony or terrace. The species develops its special effect especially in combination with other early-blooming and color-matching flowers and perennials such as:
- Iris hybrids, dwarf irises
- Dwarf tulip (bot. Tulipa polychroma)
- Hyacinths (bot. Hyacinthus orientalis)
- Small grape hyacinths (bot. Muscari botryoides)
- Gold crocus (bot. Sternbergia lutea)
You can also combine the pretty plants with many other rock garden plants, with the white-flowering species in particular showing off particularly well against gray-leaved perennials.
Appearance, leaves and growth
The star flower, which grows to a maximum height of 20 centimeters, is a so-called onion flower, which, after the early spring shoots, retreats into its hibernation organs in the ground and rests in time for the great summer heat. In autumn some leaves appear again and also overwinter. The fleshy, basal leaves can be up to 25 centimeters long and are very narrow. The slight smell of leek is characteristic, which reveals its close relationship with leeks, onions, etc.
Flowers and flowering time
In contrast to the slightly sharp leaves, the delicate flower stars, up to four centimeters in diameter, exude a delicately sweet scent. The six wide and slightly tapered petals have a light, violet-white color in the wild form. There are also many cultivars with white, purple, blue or pink flowers. Star flowers delight with their unusually long flowering period for spring bloomers: the distinctive flower stars can be admired from the end of March and into May.
If star flowers offered in stores have flower colors other than those specified (e.g. yellow or orange), they are similar-looking but different species.
Toxicity
For some time now, the star flower has also been marketed as “Andean garlic”, because the leaves and flowers, which taste slightly like chives or garlic, can be chopped into small pieces and used as a garlic substitute for many dishes and as an edible salad decoration. However, caution is advised because Ipheion contains a high concentration of the steroid ecdysterone, which is also slightly toxic to humans and pets and is said to initiate the healing process in insects and crabs. Scientists suspect that the plant wants to protect itself in this way from predators or pests. The species also contains various saponins, which can also cause mild symptoms of poisoning such as nausea, vomiting, headaches or dizziness.
Which location is suitable?
In view of its location, this is a barren, mountainous Andean flower quite undemanding. It grows in both sunny and partially shaded places, as long as they are protected from the bright midday sun. It is ideal to plant them in a location that only receives morning or afternoon sun, as this most closely matches their natural environment of grassy mountain slopes. Starflowers thrive particularly well when planted on the edge of or under ornamental shrubs and under tall, light trees. However, it should still be bright and sunny here, as the plant does not sprout and bloom in the shade. Furthermore, the bulbs can be distributed throughout the lawn so that the green carpet is covered in numerous colorful flowers in spring.
Floor
According to their natural habitat, star flowers prefer soil that is neither dry nor wet, even in beds. A sandy-loamy, well-drained, loose soil rich in minerals and nutrients is ideal. Planting in rock gardens or steppe beds is ideal.
For pot specimens, cactus soil mixed with clay granules (€19.00 on Amazon) is recommended.
Planting star flowers correctly
Even if some catalog text promises something different: star flowers are best planted in autumn, otherwise they get out of their seasonal rhythm. Place the onions in the bed between September and November as follows:
- Punch a planting hole in the ground using a piece of planting wood.
- ideal planting depth depends on the variety
- most varieties should be planted between twelve and 15 centimeters deep
- Planting distance between 10 and 15 centimeters
- Up to 100 bulbs can be planted per square meter to create a dense carpet
- Fill sand into the planting hole
- Put onion in it
- Fill up the soil and press it down
- Water the planting site
In spring, young plants that have already sprouted (and are often already flowering) are available, which you can either cultivate in pots or plant straight into the garden bed. However, the latter have the habit of quickly retreating back into the bulb after planting.
Watering and fertilizing
In terms of care, the onion flowers are very easy to cultivate: planted star flowers should only be watered after planting and if there is a lot of drought during the flowering period. If, on the other hand, the plants have withered and lost their leaves before the summer break, they should be kept dry. Additional fertilization is also not necessary.
Star flowers kept in planters should, however, be watered regularly and provided with a low-dose container plant fertilizer between April and September. After repotting into fresh, nutrient-rich substrate, no fertilization is necessary for eight weeks.
Cut the star flower correctly
Pruning is basically not necessary either. If you want to tidy up the bed after the flowering period and cut off the withered stems, it is best to wait until they have completely yellowed and dried out. The onion extracts the available nutrients from the flower stalks and stores them for the next shoot. However, if you remove them too early, a nutrient deficiency can occur and the onion may not sprout again. The same rule also applies to the leaves that yellow in summer.
Propagate starflower
Occasionally it is recommended to dig up the mother bulbs every few years, remove the daughter bulbs and replant them all together. Basically, this procedure is completely unnecessary, as the star flowers reproduce very reliably and can form dense carpets over time. In order for this to happen, the bulb flowers need a location that is optimal in terms of sunlight and soil, but where you have to leave them alone. For a lawn, for example, this means that it must not be mowed - because, as already described in the “Cutting” section, the withered stems and leaves should be yellowed and dried out before cutting back.
Wintering
As typical mountain plants, star flowers are also absolutely hardy here and can tolerate temperatures as low as minus 25 degrees Celsius. Therefore, you do not have to dig up the bulbs in autumn (like the tubers of dahlias), but you can simply leave them in the ground. Only the leaves that appear in autumn need frost protection. However, it is sufficient to cover them with spruce branches.
Specimens cultivated in pots also require winter protection, as the small amount of soil in the planter does not protect against freezing. It is best to care for these plants in a bright and cool but frost-free place during the cold winter months.
Tip
In regions with heavy vole infestations, you should only bury the bulbs with suitable protection, as they are often eaten by the pests.
Species and varieties
The genus Ipheion, to which the star flower belongs, belongs to the order of asparagus and is closely related to allium plants such as garlic, leeks, chives and onions. However, there is currently a lack of clarity regarding the classification of these and other starflower species in the genus Ipheion, which is why a scientific re-sorting is currently being carried out. Ipheion is the old botanical name that is still used by many dealers - but is sometimes also offered under the new generic name Tristagma. But whether Ipheion or Tristagma - it is in any case the desired star flower, of which the following varieties look particularly pretty in the garden:
- 'Album': bright white flowers, flowering period between February / March and into May
- 'Alberto Castillo': particularly large, bright white flowers
- 'Charlotte Bishop': delicate pink flower stars with darker colored midribs
- 'Froyle Mill': bright deep purple flowers
- 'Jessie': intense violet-blue flower stars
- 'Queen Fabiola': violet-blue flower stars arranged in an umbel with up to 20 individual flowers
- ‘Lilacinum’: light purple flowers
- 'Rolf Fiedler': bright gentian blue, very large flower stars, long flowering period
- ‘Whiskey Blue’: pretty sky blue flowers
Star flowers of the genus Triteleia
These species, also known as spring stars, are easily confused with the star flower described above. The plants actually look quite similar, although Triteleias grow significantly larger and bloom later. The following species are mainly cultivated in the garden:
- White Triteleia (bot. Triteleia hyacintina): flower balls up to 60 centimeters high with many white individual flowers, as a cut flower and for rock and steppe gardens
- Yellow Triteleia (bot. Triteleia ixioides): up to 80 centimeters high, umbellate inflorescences with up to 30 yellow individual flowers
- Blue Triteleia (bot. Triteleia laxa): up to 70 centimeters high, numerous light to dark violet-blue flowers
Triteleias bloom between May and June, depending on the species and variety.
