How to Grow Ranunculus? Detailed Guide to Cultivation Methods and Precautions

Ranunculus, also known as celery flower, Persian buttercup, and buttercup, is a perennial herbaceous plant of the genus Ranunculus in the family Ranunculaceae. It is native to southeastern Europe and southwestern Asia. With a low-growing form, brilliant colors, upright flower stems, and beautiful and unique flower shapes, it is suitable for planting under trees or on the north side of buildings and is deeply loved by consumers. Let us take a look at the cultivation methods and precautions for ranunculus!

Growth Habits of Ranunculus

Ranunculus prefers cool and semi-shaded environments and dislikes heat. The suitable growing temperature is around 20°C during the day and 7-10°C at night. It fears both waterlogging and drought, and is best planted in well-drained, fertile, loose neutral or slightly alkaline soil. After June, the tubers enter dormancy. It prefers a mild climate, fresh and humid air, and a shaded growing environment. It is not tolerant of severe cold and freezing, and is even more afraid of intense summer heat and scorching sun. In most parts of China, it enters a dormant state in summer. For pot cultivation, it requires a sandy growing medium rich in humus, loose and fertile, with strong permeability.

Propagation Methods of Ranunculus

1. Division: Potted ranunculus is mainly propagated by division, usually carried out in autumn from September to October. After digging out the tubers that have been left in pots to dormancy through the summer, shake off the soil and pull them apart by hand along their natural growth direction. Each separated section must have a piece of root crown, 1-2 new buds, and 3-4 small tubers. Then soak them in a 1% potassium permanganate solution for 3-5 minutes to disinfect and sterilize, let them dry slightly, and then plant.

2. Sowing: Ranunculus propagated by sowing shows great variation and is often used for breeding and mass propagation. The sowing time is in warm spring. After breaking up the soil in the seedbed, raking it fine, and leveling it, water it thoroughly once with a fine-rose watering can. Wait until the standing water on the bed surface has seeped away, then evenly broadcast the germinated ranunculus seeds on the seedbed. Cover the bed surface with a layer of sifted fine soil about 0.5 cm thick, then cover with double-layer shade netting to cool down and retain moisture.

Cultivation Methods of Ranunculus

1. Soil: Ranunculus prefers well-drained, fertile, loose neutral or slightly alkaline soil. Apply sufficient base fertilizer when planting. For pot cultivation, it requires a sandy growing medium rich in humus, loose and fertile, with strong permeability. You can use 2 parts garden soil, 1 part leaf mold, and 1 part barnyard manure as the potting soil.

2. Light: Ranunculus is not tolerant of strong light and prefers a semi-shaded environment. In winter, light should be sufficient. In spring, as temperatures rise and light intensity increases, moderate shading should be applied and ventilation strengthened. In addition, ranunculus is a long-day plant, and its flowering period can be controlled according to this characteristic.

3. Watering: Ranunculus prefers moisture and fears waterlogging. It is relatively drought-tolerant but should not be overly dry. After planting, the first watering should be thorough. Subsequent watering should be timely and balanced, and it must not be too dry or too wet. The appropriate degree of watering is when the soil surface is dry but the leaves do not show wilting.

4. Fertilizer: Before planting ranunculus, choose decomposed cake fertilizer or animal manure and other organic fertilizers as base fertilizer, and spread them evenly. After transplanting, begin topdressing when the plant shows obvious growth or grows new leaves. In the early stage, mainly use urea; in the later stage, mainly use compound fertilizer, applying once every 7 days.

5. Temperature: Ranunculus prefers a cool environment. The optimal growing temperature is 15-20°C during the day and 7-8°C at night. The temperature should not be too high or too low, and the day-night temperature difference should not be too large either. Otherwise, the growth and development of ranunculus will be affected, leading to a decrease in flower number and quality.

6. Pests: During the growing period of ranunculus, if conditions are hot and humid, it is prone to leggy growth, yellowing leaves, and stem base rot. The main pests include root maggots and leaf miners. Spray with 40% omethoate emulsifiable concentrate at 1000 times dilution to kill them. For root rot, irrigate with 50% benomyl wettable powder at 1000 times dilution.

7. Pruning: Ranunculus is a flowering plant with a graceful form and bright flower colors, and it grows relatively quickly. In the early bud stage, select and keep 3-5 healthy buds per plant and remove the rest. At this time, the potting soil should be slightly dry. After flowering, if seeds are not needed, promptly remove the spent flowers.

Disease and Pest Control of Ranunculus

1. Southern blight

[Symptoms] Southern blight mainly attacks the stem base of the plant. In severe cases, the stem base rots and becomes necrotic, separating the aboveground part from the underground part. Water cannot rise, branches and leaves wither, and the plant dies.

[Control] In the early stage of the disease, spray and irrigate the stem base of the plant and the surrounding soil with 75% chlorothalonil wettable powder at 500 times dilution and 5% validamycin at 1000 times dilution to reduce the severity of the disease.

2. Penicillium rot

[Symptoms] Penicillium rot mainly occurs during the tuber storage period. In severe cases, the surface of stored tubers is covered with a large amount of Penicillium conidia, which easily infects healthy tubers.

[Control] Promptly remove and burn or deeply bury tubers infected by Penicillium. Adjacent tubers must also be taken out, disinfected, dried, and then stored to prevent Penicillium from infecting healthy tubers.

3. Viral disease

[Symptoms] Symptoms include wrinkled and uneven leaves, mosaic patterns, chlorotic spots, or leaves shrinking and becoming thicker. In severe cases, diseased plants are noticeably stunted and wither and die.

[Control] In the early stage of the disease, spray with 68% virus wettable powder at 800 or 1000 times dilution, 3.85% virusbike wettable powder at 100 times dilution, or 7.5% keduling aqueous solution at 800 times dilution for control.

4. Root rot

[Symptoms] Infection by root rot causes the root system to rot and turn dark brown or black. The aboveground stems and leaves gradually wilt and turn yellow, and the plant dies.

[Control] In the early stage of the disease, irrigate the roots with 75% thiophanate-methyl at 800 times dilution or 50% benlate wettable powder at 1000 times dilution. For potted plants, immediately repot and replace the growing medium to control the spread of the disease.

5. Mosaic disease

[Symptoms] Chlorotic spots appear on the leaves. In severe cases, the plant grows and develops poorly.

[Control] Use healthy seedlings and do not propagate by division from diseased plants. Promptly spray insecticides to control aphids. Heat-sterilize flower-cutting tools or wash them clean with detergent.

6. Leafminer

[Symptoms] Larvae bore into and feed on leaf tissues, forming serpentine white mines. Their excrement appears as black continuous linear deposits within the mines. Adults feeding and laying eggs cause round damaged spots.

[Control] In the early occurrence period or about 20 days after the peak emergence of female flies, promptly alternate and rotate the use of 75% cyromazine wettable powder at 5000 times dilution, 4.5% beta-cypermethrin emulsifiable concentrate at 1000 times dilution, 50% chlorpyrifos at 2000 times dilution, and 25% leafminer-killing emulsifiable concentrate at 1500 times dilution. Spray once every 10 days, for 3 consecutive sprays.