Butterfly Iris Planting Methods and Key Technical Points Explained
Butterfly iris (scientific name: IIris japonica Thunb.): a perennial herb. The rhizome can be divided into a relatively thick upright rhizome and slender creeping rhizomes. The upright rhizome is flat and round, with many relatively short internodes, and is brown; fibrous roots grow from the nodes of the rhizome and are much branched. The leaves are basal, dark green, and glossy.
How to sow butterfly iris seeds
1. Sowing
In areas with a relatively warm climate, butterfly iris seeds can be sown between midsummer and late autumn; in areas with a cool climate, they can be sown in spring and autumn. The best method is still to use small flower pots for raising seedlings, and the flower soil used for seedlings should be of good quality. The germination period is about 21-28 days.
A trick for keeping the soil moist is to wrap the small pot in plastic film after watering well, then place the flower pot in a shaded, warm, and bright place.
2. Transplanting seedlings into the nursery
Butterfly iris likes sunlight and also has high requirements for drainage, so planting butterfly iris in a nursery is the only way to ensure its best growth. If you live in a hot climate zone, you need to find a place with afternoon shade for planting. Of course, you can also plant it in hanging flower pots or ordinary clay pots according to your needs.
3. Soil and fertilizer management
The cultivation soil can be mixed from 65% humus soil, 20% clean sand, and 15% fine stove ash. From the Autumn Equinox to the Winter Solstice, apply a solid fertilizer once to butterfly iris; apply less nitrogen fertilizer and more phosphorus fertilizer and potassium fertilizer. Eggshell powder and thoroughly decomposed fishy water are very good phosphorus fertilizers, while bran ash and tobacco ash are readily available potassium fertilizers. A nitrogen, phosphorus, and potassium compound fertilizer can also be applied to promote the sprouting of more new plants and leaves.
4. Watering
The soil should not be too dry or too wet. Each watering must be thorough, and after buds appear, water a little more. About every 20 days, combine watering with applying fermented soybean cake water, diluted fishy water, and water from soaking water chestnuts, etc., combining watering and fertilizing. When the room temperature is low, watering should be controlled to prevent the potting soil from becoming too wet; overly wet potting soil can cause root rot and death, but the potting soil should not be allowed to become too dry either.
5. Heat preservation
The suitable temperature for butterfly iris in winter is 15°C-20°C, and it is best not to go below 10°C. After the flower stalk shoots up, the temperature should be maintained at around 18°C, and the temperature difference between day and night is best at around 10°C; otherwise, the flower stalk will bloom before reaching the proper height. Therefore, when the nighttime outdoor temperature is below 10°C, it must be moved indoors.
When the indoor temperature is below 10°C, in addition to covering the surface of the potting soil with a 1 cm thick layer of charcoal powder for heat preservation, it should also be placed in a sunny and warm place indoors. When the indoor temperature is especially low, a film can be placed over the flower pot to raise the temperature, but the temperature inside the cover must not exceed 25°C; if it exceeds that, ventilation is needed to lower the temperature.
6. Adjusting light
Under normal circumstances, during the day it should be placed in a sunny spot indoors so that it receives sunlight and maintains its original color. Before flowering, at night it should also be placed under a fluorescent lamp for supplemental indoor lighting. Because the two rows of leaves of butterfly iris are opposite, if the light remains in one position for a long time, the leaves will grow unevenly and affect the ornamental effect. For this reason, when adjusting the light, attention should be paid to the direction of the leaves, and the side facing the sun should be changed about every 10 days.