Flowers 101: Ranunculus. Season: Ranunculus are generally in season from January to May – plus or minus a month depending on the weather in the growing regions. Cost: Ranunculus are a cost effective alternative to other multi petaled flowers like peonies, garden and cabbage roses.Expect to pay $2-$3 per stem to start.Colors: White, yellow, peach, orange, pale pink, hot pink and red. Hardiness: Ranunculus are delicate blooms and need lots of water. They are an exceptionally thirsty bloom so keep them hydrated as much as possible.lowers 101: Ranunculus. Season: Ranunculus are generally in season from January to May – plus or minus a month depending on the weather in the growing regions. Cost: Ranunculus are a cost effective alternative to other multi petaled flowers like peonies, garden and cabbage roses.