When I first started growing flowers, one of the very first plants that I wanted to grow was ranunculus. Believe it or not, I found the corms for ranunculus at the local dollar store. Unfortunately, they were being sold in the spring. It didn’t work out well. I planted them, but the weather was simply too hot. The flowers grew, but they were so small.
Anyhow, since ranunculus grow best throughout the coolest part of the season, it is important that I start my corms in the fall and overwinter them into the spring. However, it’s not quite that simple. I’m in zone 6/7, and ranunculus are only cold tolerant to zone 8. This means I”ll need to plant the corms in an unheated hoophouse or low tunnel in order to ensure that my plants will survive the winter. Even in this case, I will sometimes have plant loss, depending upon how cold it is. Every garden is different.
To get my corms ready for planting, the first thing that I need to do is soak them. When they arrive, they’re small and dried up. I simply fill a container with water and drop them in for about 4-6 hours. Some people will say to aerate the water, but I’ve had good success both ways. Be careful not to soak the corms for too long, as they will plump up quite a bit. Over soaked corms can be prone to rot and damage.
After the corms have been soaked, I move them to a seed tray filled with moist potting mix. Make sure that the “arms” of the corms are facing down since the new growth will sprout from the top of the crown. Next, I gently covered the corms with more potting soil mix and moved the tray outside.
Here in my zone, I like to start my corms around the beginning of October. I place the trays outdoors, because the temperatures at this time are great for getting the corms to start growing. Ideally, temperatures in the day time should be about 60-70F and temperatures at night should be about 40-50F. With this in mind, I generally start seeing growth within one week of starting. When new growth emerges, I move the plants into their final place in the hoophouse.
Have you ever grown ranunculus in your garden? I’d love to hear all about it in the comments below! I hope you’re having a wonderful day!