Ranunculus plant dies mainly due to root rot. If the soil is deficient in Nitrogen for prolonged periods, the plant might die too. Powdery mildew is a fungal disease that’s quite common in Ranunculus plants.
Ranunculus plants are commonly called the Buttercups/Spearworts/water crowfoots. The plant is grown for its beautiful blossoms.
Ranunculus are Perennials that give out red, orange, pink, and yellow-colored blossoms that look like origami flowers thanks to multiple layers.
Ranunculus grows well in garden beds and pots. The plant does run into issues, in this article you’ll know how to fix them!
Ranunculus leaves turning yellow
Ranunculus leaves turn yellow if the plant has been sitting in waterlogged soil for a long time. Ranunculus also turns yellow if the plant doesn’t get adequate Nitrogen or Iron. Ranunculus also turns yellow if the plant doesn’t get adequate sunlight.
Dry soil also causes Ranunculus leaves to go yellow. So, you need to consider all these aspects when trying to fix your yellowing Ranunculus plant.
Why is my Ranunculus wilting?
The Ranunculus plant wilts and turns yellow when the plant has been overwatered. Overwatering leads to waterlogged soil.
Roots can not absorb nutrients/water efficiently from waterlogged soils. This is the reason for wilting and yellowing of the Ranunculus leaves.
If Ranunculus sits in waterlogged conditions for a long time, the roots get rotten. Crown rot and Root rot are favored by soggy soil.
Both these diseases are caused by fungal pathogens. Crown rot is seen in hot & humid climatic conditions. Lower leaves turn yellow followed by browning.
In Ranunculus affected by the crown rot, the lower part of the stem turns brown. Did it rain recently where you live?
Rain wets the soil too much and leeches away the essential nutrients. So, do not water your Ranunculus if it rained recently.
Tip: Check the soil moisture with your fingers/soil moisture meter. Water only when the plant is thirsty.
Root rot/Crown rot control in Ranunculus
- Water only when the top inch of the soil is dry. Check the soil with your fingers.
- Make sure the potting mix drains the excess water efficiently. Use a pot with holes that drain the excess water properly.
- Is your garden soil heavy? Clay soils are heavy and hold water for longer than desired. Mix Perlite according to the requirements to increase the drainage.
How to treat Crown rot/Root rot in Ranunculus?
- Prevention is only possible if you detect the disease early on. Drench the soil in Aliette/Captan (2 tbsp, in a gallon of water). Doing this once a month can treat the disease if you respond early.
- If the disease has progressed greatly, just discard the plant and sterilize the soil around it.
Insufficient light
Ranunculus leaves turn pale/yellow if the plant doesn’t get adequate sunlight. The plant needs bright sunlight to thrive and blossom.
Make sure your Ranunculus gets full sunlight if it’s growing in the garden. If the plant is growing indoors, ensure that the plant gets direct sunlight for at least 6 hours a day.
For indoor Ranunculus, the temperature should not rise above 60F.
Nitrogen Deficiency in Ranunculus
Ranunculus also turns yellow if the soil lacks Nitrogen. Soil becomes Nitrogen-deficient if you did not feed it adequately.
Nitrogen-deficient Ranunculus plants’ bottom leaves turn yellow. Newer leaf growth is often greener, which is the main sign of N-deficiency.
Miracle-gro(15-30-15) works well on Ranunculus plants. The higher Phosphorous levels are good for the blossoms.
Get the soil tested if you’re unsure about the Nitrogen deficiency. You can treat the plant according to the test results.
Note: Iron deficiency also turns the leaves yellow. I’ve not seen this happen to my Ranunculus yet but it’s a thing to look out for! Getting a soil test is worth it.
Natural reasons
Ranunculus leaves will turn yellow once the plant is done with the blossoms. This is completely natural and you don’t need to panic.
After the plant has done flowering, give the plant some time. Do not prune the plant now as you’ll only harm the plant.
After the leaves turned yellow completely, prune off such leaves in the Fall. You can prune such leaves at the base to promote the next batch of flowering.
Doing this you’ll also let the corm rest till the next season.
Ranunculus Mildew
Powdery mildew is a common fungal disease that can affect Ranunculus. Powdery mildew signs are seen primarily on the leaves.
Powdery mildew spores grow on the wet leaves. So, leaving your leaves wet for a long time is not a good idea.
Do not wet your Ranunculus leaves when watering. Wet leaves are a good habitat for a variety of fungal spores.
A white layer forms on the infected leaves of the Ranunculus plant. This layer forms on the upper sides of the leaves.
On the lower side, one can clearly see the fungal outgrowths. Symptoms develop on the undersides of the leaves initially.
Treat Powdery mildew in Ranunculus
- Baking soda mixed with detergent and water can eliminate the spores of Powdery mildew efficiently.
- Sulfur-containing organic fungicides work to prevent and treat Powdery mildew in Ranunculus.
- Prune off the infected leaves of your Ranunculus using a pair of sterilized pruning shears. If you do this as soon as you see the early signs, you can prevent a large-scale infection.
Ranunculus leaves curling
Ranunculus leaves get distorted/droop due to overwatering and many other reasons. If the leaves are curling and you see insects inside them, it is an aphid infestation.
Aphids curl the leaves inward and hide inside the distorted/curled leaves. Aphids suck on the plant sap, making the plant weak.
Aphids excrete a sticky material called Honeydew which attracts a variety of fungi. These fungi grow on the plant to form the black, ugly ‘sooty mold’.
How to get rid of aphids on Ranunculus?
- You can dislodge aphids on the affected Ranunculus by spraying a forceful stream of water on the affected stem.
- Hang sticky, yellow cards around your Ranunculus plant to identify an infestation early on.
- Spray Neem oil on the affected branches of Ranunculus to get rid of these pesky pests naturally.
- You may want to spray Insecticidal soap on the affected branches to eliminate these pesky pests.
Happy Growing 🙂