- origin and distribution
- use
- appearance and growth
- flowers and flowering time
- toxicity
- location and soil
- Plant irises properly
- Water irises
- Fertilize irises properly
- Pruning irises properly
- Propagating irises
- hibernate
- species and varieties
The sword lily or iris enchants the viewer with its beautiful flowers that shine in the most diverse colors of the rainbow. The genus is extremely rich in species and varieties, with the right variety for every location. Whether shady and moist soil or dry subsoil and sun: the gardener has the choice. Most species are hardy and also pleasingly uncomplicated to care for.
The iris is an exotic beauty
Table of Contents
Show all- origin and distribution
- use
- appearance and growth
- flowers and flowering time
- toxicity
- location and soil
- Plant irises properly
- Water irises
- Fertilize irises properly
- Pruning irises properly
- Propagating irises
- hibernate
- species and varieties
- Dwarf irises (Iris barbata 'Nana' hybrids): up to 30 centimeters high, flowering from mid-April
- Medium-sized bearded irises (Iris barbata 'Media' hybrids): growth height up to 70 centimetres, flowering period from the end of April / beginning of May
- Tall bearded irises (Iris barbata 'Elatior' hybrids): growth height of more than 70 centimetres, flowering from the end of May
- 'Calling Cadence': two-tone yellow and burgundy flowers, height of growth about 90 centimeters
- 'Christmas Eve': two-tone white and yellow flowers, height of growth approx. 95 centimetres
- 'Cracklin Rosie': burgundy red flowers, height of growth about 100 centimeters
- 'Crooked Little Smile': two-tone yellow and blue flowers, height of growth approx. 80 centimetres
- 'Embrace Me': pink flowers, height of growth up to approx. 100 centimetres
- 'Joyful Journey': flowers in orange and yellow, height of growth up to approx. 90 centimetres
- 'Misty Morning Melody': two-tone blue and white flowers, height of growth approx. 95 centimetres
- 'Shelter from the Storm': two-tone blue and light blue flowers, height of growth approx. 100 centimetres
- Bristle iris (Iris setosa)
- Great iris (Iris magnifica)
- Naked-stemmed iris (Iris aphylla)
- Reticulated Iris (Iris reticulata)
- Rainbow iris (Iris innominata)
- Butterfly iris (Iris orientalis)
- Terracotta iris (Iris fulva)
- Marsh iris (Iris pseudacorus): native species
- Siberian iris (Iris sibirica): also meadow iris
- Japanese Iris (Iris ensata)
- Japanese flag (Iris haematophylla)
- Steppe iris (Iris spuria)
- Hybrid iris (Iris Spuria hybrids)
- Grass iris (Iris graminea)
- Colorful iris (Iris variegata)
origin and distribution
Irises are only native to the northern hemisphere and almost exclusively in the temperate climate zones - but the magnificently blooming summer flowers can be found in an unmanageable variety on almost every northern continent. Incidentally, the genus name "Iris" refers to the Greek goddess of the rainbow of the same name, because irises are also available in an incredible variety of colors. The spectrum of the different flower and growth forms is just as inexhaustible, as there is a wide range of variants, from the low-growing dwarf forms to the tall-growing bearded iris. No wonder, then, that the Bund deutscher Staudengärtner named the popular plant “Perennial of the Year” in 2016.
use
The possible uses for irises depend largely on the type and variety chosen. Varieties for moist substrates feel at home at the edge of a garden pond or a stream, while iris species adapted to dry and sunny locations fit wonderfully into perennial beds or in the rock garden. You can also cultivate the magnificent perennials in pots, provided there is an adequate supply of water and nutrients. In particular, the dwarf forms - such as low bearded irises - are suitable for a bucket culture.
In the bed, the pretty flowers with the unusual blossoms are often combined with perennials and bulbs such as peonies (Paeonia), delphiniums (Delphinium), daylilies (Hemerocallis), poppies (Papaver), tulips (Tulipa) and lavender (Lavandula) as well as with grasses such as such as blue fescue (Festuca cinerea) or giant feather grass (Celtica gigantea).
appearance and growth
With the exception of the netted iris, all iris species form rhizomes or tubers, not bulbs such as daffodils or crocuses. In spring, the long, sword-like leaves and the flower shafts, which are between 15 and 120 centimeters high depending on the species and variety, peel from these outlasting organs. After the development and maturation of the capsule fruits in late summer or autumn, all above-ground parts of the plant die off and only the rhizome or tuber overwinters. Irises are among the herbaceous, perennial plants.
flowers and flowering time
The beauty of irises is primarily due to their unusually structured flowers, which shine in many different colours. Characteristic of iris flowers is their tripartite division: each consists of three upright standards and three other bracts that hang downwards. They can be of the same colour, but they can also be colored differently. In some varieties, the bracts are also fringed or ruffled at the edges, and the various bearded irises have a hairy "beard" at the back of the flower. The pistil, which consists of a three-branched style and the anthers, sits between the dome and the bracts.
toxicity
Parents have certainly heard of the violet root as a teething aid for babies or even offered it to their child. Contrary to all assumptions, the root, which has been used for centuries, does not come from the blue violets, but from the sword lily or iris. The native yellow iris, which is also known as marsh iris, is also used in homeopathy as a wound healing agent.
However, such traditional uses in folk medicine should be treated with caution: All iris species are poisonous and can cause typical symptoms of poisoning such as vomiting, diarrhea, nausea, etc. In addition, irritation of the mucous membranes, increased salivation and difficulty swallowing occur after consumption due to the pungent substances contained. This not only applies to humans, but also to domestic and farm animals such as cattle, sheep, goats, horses, dogs and small rodents.
location and soil
The ideal location for irises depends on the specific species. Typical marsh plants such as the Siberian iris (Iris sibirica, also known as meadow iris) or the native yellow iris (Iris pseudacorus) fresh to wet places in the garden, for example on a damp meadow or directly at the edge of the pond.
Other irises, on the other hand, require a rather dry location with nutrient-rich, loamy and well-aerated soil and plenty of sunlight. In contrast to the marsh iris, these species do not tolerate permanent moisture and are therefore best placed in perennial beds or even in the rock garden. The popular bearded iris, for example, is quite drought tolerant and therefore harmonizes very well with similar species such as sedum or thyme.
Furthermore, the small species in particular can be cultivated very well in pots, provided you protect the planters from excess moisture - especially during winter.
Plant irises properly
The ideal time for planting all types of irises is between the end of July and the beginning of October, although you can plant the rhizomes in the ground in March or November, weather permitting.
When planting the rhizomes, make sure that they are laid flat in the planting pit and that the top third still protrudes from the ground. Before planting, loosen the soil thoroughly and add compost and, if necessary, sand to the excavation. For improved drainage in the case of rather heavy, loamy subsoil, pour a thumb-thick layer of sand into the shallow planting pit and place the rhizomes on top.
For an extensive planting, for example for a border, you should plan between 12 and 16 low-growing irises and between five and seven tall-growing species per square meter.
Water irises
Planted and well-rooted irises only need to be watered if the drought persists. On the other hand, specimens cultivated in pots must be watered regularly, but must not stand wet - good drainage is therefore essential, and a thumb test must be carried out before each watering.
Fertilize irises properly
It is sufficient for irises in the garden to be fertilized with compost and a handful of horn shavings (€32.93) in March or April, which can be repeated again in June if necessary (e.g. if there are signs of deficiency). Alternatively, or for potted plants, use a potash fertilizer.
Pruning irises properly
Cut the wilted flowers about four inches from the ground to prevent seeding. Some irises can be persuaded in this way to have a second flowering period. The leaves, on the other hand, are only removed in autumn when they are withered and can be easily peeled off. Do not take this step earlier, as the underground rhizomes or tubers extract valuable nutrients from the foliage and store them for the next shoot.
Propagating irises
Every three to four years you should dig up the large-flowered species in late summer and divide the rhizomes. In this way, you not only multiply the irises, but also rejuvenate the otherwise senescent plants and thus ensure increased flower development. Cut through the rhizomes at the constricted sections, each section should have roots and a tuft of leaves. Shorten the leaves by about half so that the plants do not lose moisture unnecessarily before they root.
hibernate
Irises are usually hardy, so the bulbs or rhizomes can remain in the ground during the winter months. The Siberian iris and other species suitable for moist soil are also given a cover of straw and leaves. Irises cultivated in pots can also overwinter outdoors but should be placed in the rain shade or under a canopy.
tips
Make sure your iris plantings are well protected from slugs, as they will eat off the juicy leaves within a very short time. Voles, in turn, taste the nutritious rhizomes or tubers.
species and varieties
The group of irises (bot. iris) is huge: 285 wild species alone are known, most of which come from the temperate climate zones of the northern hemisphere. In addition, there is an almost unmanageable number of natural hybrids and cultivated forms, of which the so-called bearded iris is probably the best known. However, this is not a specific species, but a group of iris varieties with one characteristic feature: their flowers not only bloom in all colors of the rainbow, but also have a small beard.
Popular culture forms
While botanists divide the genus into six different subgroups, gardeners only distinguish between bulbous and rhizome irises. The last group includes the bearded irises already mentioned, which in turn are sorted into three further subgroups:
Interesting varieties for the garden are, for example, these:
Other hybrid species
Over the centuries, various hybrid species and varieties have developed in a completely natural way, which are also often planted in the home garden:
Wild species for the garden
Furthermore, the gardener makes a distinction between irises for damp locations and irises for rather dry locations. These uncomplicated species are ideal for the swamp bed or the edge of the pond:
The following species, on the other hand, prefer a dry and sunny place in the garden: