I someone would ask me, I would say that no garden is complete without at least one member of the ephemeral genus of Corydalis. The more common is the delightful Corydalis solida, plus other bulbous species but wait until you meet the lord of the genus: Corydalis nobilis. If lucky to be able to drive you can see it in flower at Lost Horizons Nursery  (not applying anymore, the nursery has closed down). It does not look quite like a Corydalis and it is hard to believe that it will  become dormant in early summer.

Corydalis nobilis in early spring

Sometimes called Siberian Corydalis, Corydalis nobilis (Fam. Fumariaceae) was introduced in cultivation in Sweden in 1765 due to a fortunate mistake. The  seeds received by Linnaeus were collected from Siberia (Altai mountain range) and believed to be of Lamprocapnos spectabilis. This wonderful Corydalis is said to still grow happily in Carl Linnaeus’ gardens at Upsalla and at Hammarby. Unfortunately, the prediction of  “a great horticultural future” for this species has not become true yet. Not being very easy to propagate might have something to do with this; in fact it is not difficult to grow from seeds as long as they are fresh. It is available only from a few specialty nurseries in Europe and North America, and of course some years at Lost Horizons.

Corydalis nobilis is very cold hardy and will start growing quite fast in the spring achieving a 30-50+ cm tall clump with juicy stems and green-blue ferny leaves. It produces lots of dense inflorescences, with 20-35 flowers, golden yellow with the inner petals dark violet at the top and they are spicy fragrant. Flowering lasts for about three weeks in April-May. It sets seeds, then becomes dormant somewhere in June.

Corydalis nobilis inflorescence

Origin: NW. Siberia, Kazakhstan, Mongolia, N. Xinjiang (China). Propagated by seed (sown immediately when ripe, otherwise the ants will run away with them to feed on the elaiosomes) or by division in the fall. Corydalis nobilis has an irregularly branched, fragile rootstock, not easy to divide; it is best grown from fresh seeds. It can grow in full sun or shade, but will thrive best in a place reasonable dry during the summer.
A focal point in the spring garden, the Lord of the genus Corydalis never fails to attract attention and questions from the visitors.

Corydalis nobilis in the Display Garden at Lost Horizons

While I was away for a couple of weeks, things have gone crazy in the garden. Yesterday I run outside in a hurry to take a few images of the reticulate irises. I really love these dwarf irises and I planted them everywhere: in the sun, in part shade, in containers and every other corner where I can still dig a small hole, including small pots for winter flowering. The name of the genus comes from Iris the ancient Greek Goddess of the Rainbow. Along with the snowdrops and crocuses the reticulate irises announce the beginning of Spring with a splash of colours. 

Iris reticulata ‘Purple Gem’

They belong to a group of small bulbous irises from Turkey, Iran, Iraq, Georgia and adjacent areas. In the spring, it is easy to recognize their leaves, which are square or almost cylindrical in cross section. The bulbs have netted tunics, hence the common name: Netted Irises. Most of them are very hardy, flowering in early spring as soon as the snow melts, and going dormant in the summer. Very easy to grow, they require only a very well drained soil, in order to survive dormancy.

Iris reticulata ‘ J.S. Dijt’

Iris reticulata is the best known species with colours ranging from sky blue to violet to purple. There are quite a few cultivars in the trade and some that are hybrids with other species. With careful selection you can have a display of dwarf irises from early March till April, depending on the location.

The queen of the dwarf irises in my garden is Iris ‘Katherine Hodgkin’. The result of a cross between Iris winogradowii and Iris histrioides done by British plantsman E.B. Anderson in 1960, it flowers right after the wild I. reticulata and it has big, orchid-like flowers with an intriguing pattern.

Iris ‘Katherine Hodgkin’

Other species not so often cultivated from this group include: I. pamphylica, I. histrio, I. danfordiae, I. kolpakowskiana and I. bakeriana. Check out Alan McMurtrie’s website to see what hybridizing reticulate irises involves and from there you’ll be able to have a look also at Janis Ruksans catalogue.

 Update – Spring 2013

Just a few more images with dwarf Irises from my small rockery – I particularly liked the combination with Eranthis hyemalis (Winter aconite). What remains to be said is that after flowering the leaves will continue their growth in order to feed the bulbs for the next year flowers. This translates in a period of some sort of ‘weedy-ness’ which can hardly be obscured by other plants in a small area. Therefore, for next year I will move quite a few of them from the rockery in containers.