There are more than 200 species of iris and the botanists are having a field day classifying them. In practical terms, all we have to figure out on this website is which ones come from bulbs. The perennial rhizome-type such as I. sibirica and I. germanica are covered over at my perennial flower website

These small bulbs make excellent plants for rock gardens (they want great drainage) in the full sunshine.

Instant charm for the garden


Combine bulbous iris with other spring bloomers such as snowdrops, winter aconite, and crocus for instant charm in the rock garden, under shrubs or mixed through the perennial gardens. I note that some of these iris have been damaged in years where there has been an early spring – encouraging them to spring up – and then the weather turns cold and frosty. There has been some damage on my bulbs in these conditions.

Also, unless you give these plants absolutely the perfect conditions, they tend to be short lived. Generally, dry during the summer months is the critical thing and if you grow them where you irrigate or tend other plants, they will tend to be short-lived.

The best ones I ever grew were in a hard rocky soil beside a driveway where they never got fed, never got watered and the gravel soil drained so well that any other rainfall seldom stayed around longer than a few minutes. They do make excellent bulbs for growing in pots as long as you protect them from deep freezing in the winter. They are perfect cold frame candidates.

If you live in a climate where summer heat is high (particularly when combined with high humidity) you're going to have trouble keeping these bulbs alive and happy.

“Dutch iris”


Dutch Iris are hybrid bulbs and the flower range is much higher than with species bulbs below. Contrary to the advice above, grow these bulbs in a deep, rich soil. The flower stalks are longer than the species and they make an excellent cut flower (these are the small iris in bouquets – they are a main crop for cut flower producers).

Flowering colour: deep and light blue, purple, yellow and white
Flowering period: June - July
Average plant height: 15-18 inches
Planting depth to base of bulb: 5-6 inches
Spacing between bulbs: 3 inches
Light requirement: full sun


Most commonly available varieties include:

Apollo': yellow and white
'Blue Diamond': blue
'Blue Magic': deep purple-blue
'Blue Ribbon': ('Professor Blaauw'): deep blue
'Casablanca': white
'Hildegarde': light blue
'Ideal': sky blue
Imperator': blue and orange
'Madonna': white
'Purple Sensation': deep purple
'Royal Yellow': yellow
'Saturnus': white and pale yellow
'Symphony': yellow and white
'Telstar': deep blue
'White Bridge': pure white
'White van Vliet': pure white
'White Wedgwood': pure white

Iris bucharica


This iris has the typical iris fragrance and as a small bulb, it is worth getting down on your hands and knees to catch it in the early spring.

Flower colour: white and golden-yellow
Flowering period: April
Average plant height: 15 inches
Planting depth to base of bulb: 3 inches
Spacing between bulbs: 3-4 inches
Light requirements: full sun

Iris danfordiae


This bright yellow charmer is one of my favourite of the bulbous iris plants. It is such an early bright, cheerful bloomer in the rock garden that it always drew admirers.

Flower colour: bright yellow
Flowering period: February-March
Average plant height: 3 inches
Planting depth to base of bulbs: 3 inches
Spacing between bulbs: 3 inches
Light requirements: full sun to partial shade

Iris reticulata


This particular flowering bulb is my favorite spring bloom. The flower is immense in relationship to the size of the plant and you'd wonder how such a short plant could grow and support such a fine blossom. While the texts say that naturalizing is possible, I never had this happen. The bulbs got larger but it never produced baby plants. No matter, I like this bulb. Summer heat and perfect drainage will keep this Turkish native alive. This is my driveway plant.

Flower colour: purple, light and dark blue to violet purple
Flowering period: February-March
Average plant height: 3 inches
Planting depth to base of bulb: 3 inches
Spacing between bulbs: 3 inches
Light requirements: full sun to partial shade



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