How to Plant Iris Seeds? A Detailed Guide to the Planting Method

Iris is also known as blue butterfly, purple butterfly, flat bamboo flower, etc. It is a perennial herb of the genus Iris in the family Iridaceae. In production, division and sowing are mostly used for propagation. Division can be done after flowering in spring or in autumn. Generally, plants are divided and replanted once every 2 to 4 years. Seeds should be sown immediately after they mature. Seedlings need 2 to 3 years to bloom. Now let us take a look at how to plant iris seeds!

How to plant iris seeds?

1. Prepare a flower pot, preferably a shallow pot, such as a bonsai pot. A height of about 10 is suitable. Prepare some fine sandy soil. Evenly scatter fully mature seeds directly (preferably with a spacing of 1 to 2 cm between each) into the shallow pot already filled to 70% to 80% of its capacity.

2. Then cover with a layer of fine sandy soil, 0.3 to 0.5 cm thick. Slowly immerse the pot in clean water. The water should not go over the rim of the pot, but should preferably be level with the height of the sandy soil. Let the water slowly seep in from the bottom. Once the surface of the sandy soil is completely moist, gently lift it out and place it in a location with good light.

3. Afterward, whenever the surface of the potting soil is found to be dry, soak it in this way or spray it thoroughly with a fine-nozzle watering can. Seedlings generally emerge in 7 to 10 days. If you are not sowing in a flower pot, you can water with a fine-nozzle watering can or a sprayer.

How to Grow Iris

1. Soil: Iris grows poorly in acidic soil. Therefore, to grow iris, you should choose a clay loam rich in humus, or an alkaline soil mixed with lime. Before planting, the soil should be thoroughly turned, and well-rotted compost plus a small amount of bone meal, plant ash, etc. should be applied as a base fertilizer. In addition, iris should not be planted too deep, and the rhizome should be pressed firm.

2. Temperature: The optimal growing temperature for iris is 15 to 17°C. It prefers a sunny and moist environment. However, if the light is too strong, appropriate shading should be provided. If the humidity is too high, the humidity can be reduced by heating and ventilation.

3. Watering: After planting iris, water it thoroughly once. After that, water according to the dry and wet condition of the soil. Generally, it is better for the soil to be slightly dry. Do not let the soil become waterlogged or remain too wet for a long time, so as to avoid root rot or disease. To keep the plant looking attractive, the leaves can be cleaned.

4. Fertilizing: From spring sprouting and growth to before flowering, iris should be given 1 to 2 applications of well-rotted, diluted cake fertilizer water or compound flower fertilizer. After the flowers fade, it is best to apply liquid fertilizer once more.

Pest and Disease Control of Iris

1. Crown rot

[Cause] Crown rot is caused by Sclerotium rolfsii. It only occurs in subtropical and warm-climate regions. Below 13°C, this disease does not infect plants. When the temperature is above 20°C, the disease is most severe. It has quite a large number of host plants. Prevention and control mainly rely on strengthening management. Once the soil is infested, it persists for a very long time.

[Control] Do not plant bulbs in soil that has been infested by Sclerotium rolfsii; otherwise, soil treatment and bulb treatment must be carried out. Carefully remove diseased plants and the soil around them.

2. Gray mold

[Cause] Gray mold is caused by fungi of the genus Botrytis. It usually occurs under humid conditions and also harms many crops and plants.

[Control] Avoid leaf damage. Bulbs whose new shoots are longer than 5 cm should no longer be planted. In particular, plastic mulch must not be used, so as to avoid sun scorch. Do not plant bulbs too densely, and keep the soil free of weeds during the growing period. In the greenhouse, maintain relative humidity at around 80%. If necessary, turn on the fan and heating to keep the plants dry. Water in the morning to ensure the plants stay dry. After leaf damage, spray fungicides as needed.

3. Rhizoctonia disease

[Cause] The Rhizoctonia that infects corms and buds mainly comes from the soil. Many plants (such as tulips) can be infected by it, even in soil where flowering bulbs have never been planted. It can cause disease regardless of soil temperature, and the probability of disease increases when the temperature rises.

[Control] Carry out routine soil treatment in soil that has been infected or may have been infected. Under high temperatures, soil re-infection may still occur. Maintaining a clean environment can prevent re-infection. Without routine soil treatment, past experience shows that the soil will be infested by Rhizoctonia, so appropriate fungicides should be applied before planting.

4. Root rot

[Cause] Pythium ultimum infects the root system through the soil. This fungus can be found in any soil and is very difficult to control. The degree of infection varies among varieties. Planting immediately after soil steam sterilization makes the harm of early infection very great, because at this time the competitive organisms in the soil have not yet recovered.

[Control] Rotate with various other crops or carry out routine soil treatment once a year. Treat bulbs before planting. Ensure a suitable soil structure. Use a suitable irrigation system to maintain good soil structure while preventing waterlogging.

5. Root nematode disease

[Cause] Infection of plants by Pratylenchus penetrans induces this disease. Some unknown fungi or bacteria gather near the wounds caused by nematodes and can harm many plants (including chrysanthemums, roses, and lawns).

[Control] Carry out soil treatment once a year.

6. White flower disease

[Cause] In the greenhouse, weak transpiration causes relatively high humidity.

[Control] If the relative humidity in the greenhouse is high throughout the growing period, maintain the greenhouse temperature 2 to 3°C higher than the outside temperature. If the outside temperature is high (15 to 16°C) and this method cannot be used, heat the greenhouse in the morning and turn on the ventilation fan.