The two most common type of Irises grown are the Bearded and the Siberian Irises. Members of the genus Iris bloom between the months of February and May, depending on the species.
Tips for Iris Flower Care
Planting Site Preparation
Before planting the iris plant, you need to choose a planting location. The place should receive between six and eight hours of direct sunlight each day and have good air circulation. Two weeks before planting the Iris rhizomes, the soil has to be prepared.
Spread two to three inches of organic compost over the planting site. Use a tiller to break the soil up and mix in the compost. Remove any visible rocks which can serve as an impediment to the root system.
Iris Flower Planting
Dig a hole large enough to hold the Iris rhizome and form a small cone in the bottom of the hole. This allows the pointed tip of the rhizome to emerge from the surface. Now place the rhizome in the hole, and spread the roots out as much as possible. Fill the hole with soil and water.
This should help compact the soil around the roots and fill up any air pockets in it. Allow a space of at least eight inches before planting the other Iris rhizomes. This allows sufficient room for root growth.
For encouraging a nice flush of blooms you need to keep to keep the soil moist (not wet). Water the Iris rhizomes thrice a week and reduce it to twice a week after growth begins. This should be done so as to allow the soil to dry slightly between watering. In winters, the iris flowers need to be watered just once a week and only on weeks with no rainfall.
Fertilizing and Mulching
You need to use fertilizer once a month during spring and summer. In the fall and winter seasons, fertilization is not needed as the Iris plants do not absorb all the nutrients and the excessive fertilizers in the soil can result in root burn. Water the soil after applying the fertilizer to help it integrate into the earth.
Also, just before frost, you need to spread the mulch around the Iris plants. This prevents the temperature of the soil from fluctuating, resulting from constant freezing and thawing.
Once the flowers have faded to an inch or two above the rhizome, cut the flower stalks back. This should prevent seed formation and allow vigorous growth. In the fall season, you need to cut the leaves back to 6-8 inches above the ground to prevent future insect and disease problems.
If heaving occurs, it is best not to force the plants back into the soil and instead, cover the rhizomes and the roots that are exposed with some soil.
After 3 to 5 years, once the clumps become crowded, it may be beneficial to divide them. This can be done 4 to 6 weeks after flowering. All you need to do is cut the leaves to one-third their length.