How to Grow Ranunculus

Purchase ranunculus bulbs and corms from nurseries, mail-order suppliers, or big box stores. It’s best to buy the largest bulb size available in high quantities to ensure prolific blooming and the best bang for your buck. Store bulbs in a cool, dry place for up to three months until you’re ready to plant them. When it’s time to plant your ranunculus, first soak the bulbs in room temperature water for no longer than four hours, freshening the water every hour, to bring them out of their dormant state.

Once your soaked ranunculus bulbs have expanded, plant them 2 inches beneath the soil and about 6 inches apart from each other, with the claw side face down. Cover them with more soil and finish with an initial watering. Use a rich, moist soil that has good drainage, and add compost to enrich the soil if necessary. The best time to plant your ranunculus is typically in the fall, but if temperatures dip below freezing where you live, it’s better to wait for late winter or early spring. Look forward to seeing your flowers bloom about 90 days after planting.

Your ranunculus will be happiest if it has access to plenty of sun every day — at least six hours’ worth. Place it in direct sunlight; give it shade during the hottest part of the day if you live in a very warm climate. A temperature range of 40 to 80 degrees F is ideal for ranunculus. If you plan to grow yours indoors, make sure to find a spot by a south-facing window for optimal sun exposure in the afternoon.

Ranunculus doesn’t do well in overly wet, soggy soil, so avoid overwatering it. Once it has been planted, water your ranunculus in the morning with a drip hose every two weeks. Switch to once-a-week watering when the first leaves appear, and then cease watering in the fall when your ranunculus goes dormant and stops producing flowers.

The question of fertilizing your ranunculus depends mainly on whether you plan to grow it as a perennial or annual. If you choose the former, encourage blooms by fertilizing your plant once a month starting in the spring. However, if you plan to grow your ranunculus as an annual — as many gardeners do — then fertilizing isn’t necessary.

Annual ranunculus varieties are best suited for USDA zones 4 through 7, which includes most central states. Perennials, on the other hand, do well in the warmer climates of zones 8 to 10 — California, Florida, and many southern states.

Pruning your ranunculus is essential to preventing diseased foliage from taking over. Sterilize sharp pruning shears before each use; this helps to keep your shears free of pests as well as to avoid disease transfers between plants. After removing any dead or dying leaves, be sure to collect any that have fallen on the ground to prevent the spread of disease.

If you live in a warm climate, all your ranunculus plants need in the winter months is access to sunlight. Ranunculus do need a little help in areas where the temperature falls below freezing, however; simply add a layer of mulch to the root system and cover the plants with frost cloths and hoops.

If you hope to propagate your ranunculus, plan to do so in the fall. The most common method is dividing the tubers and removing the offsets; then, immediately repot them in rich soil. You can also wait and pot it later in the spring as long as you store it in a cool location in a box full of damp peat moss or sand.

Are your ranunculus plants starting to wilt? The most likely cause is root rot, a fungal condition caused by overly wet soil. You can prevent root rot by planting your ranunculus in a place with well-draining soil and good airflow, but if your plant is already showing signs of infection, it's best to dispose of it and the soil.

Like all plants, ranunculus is susceptible to damage caused by pests — in particular, slugs and aphids. If you notice yellowing or curled leaves with tiny oval bugs clustered on them, you have an aphid infestation. Eliminate them with an insecticidal soap spray or by making your own concoction from a few drops of dishwashing detergent in a spray bottle of water. Slug infestations are even easier: simply pick the slugs off by hand at night.

Ranunculus is a popular choice for adding a lively burst of color to gardens and floral arrangements, thanks to its wide variety of hues. It is an ideal candidate for bedding plants since it makes quite a statement in a group and is equally show-stealing in a bouquet.

You could easily compare ranunculus to peonies, another fluffy perennial that is made up of many delicate petals. Peonies have a larger bloom size and more prominent stem, but ranunculus can’t be beat for the color options. Both flowers are a popular choice in wedding bouquets.

Make sure to keep children and pets away from your ranunculus plants as they are poisonous and can cause illness. Signs of ranunculus poisoning include blistering and swelling of the mouth, vomiting, and diarrhea. Fortunately, most pets leave ranunculus alone due to their unappealing taste.

When choosing your ranunculus, you’ll find that there is no shortage of options. More than 600 varieties of ranunculus exist, and it comes in almost every color you can think of, from red, pink, and purple to pale orange, yellow, and white. One of the most popular varieties is the Persian ranunculus or Ranunculus asiaticus, which is known for its sturdy stems and brilliant, crepe-textured petals.