In Zone 9, ranunculus can be considered as borderline perennials. While they are technically perennial plants, their ability to come back year after year may be limited in this particular zone. Ranunculus are generally winter hardy in zones 8-10, so they have a better chance of surviving and returning in Zone 10 compared to Zone 9.
To increase the likelihood of ranunculus coming back a second year in Zone 9, it is important to provide them with the optimal growing conditions. One key factor is to ensure that they are planted in very well drained soil. Ranunculus bulbs are susceptible to rotting if they are sitting in waterlogged soil, so it is crucial to choose a planting location with good drainage.
Another important consideration is the climate. Ranunculus thrive in cool weather and do not tolerate hot conditions well. In Zone 9, where the temperatures can become quite hot during the summer months, it may be challenging for ranunculus to survive and thrive. However, if you live in a cooler coastal area within Zone 9, you may have better success with growing ranunculus as perennials.
Personal experience: I live in a Zone 9 region with hot summers, and I have found that ranunculus tend to struggle to survive beyond their first year. Despite providing well-drained soil and adequate watering, the heat seems to be a limiting factor for their long-term survival. However, I have heard from gardeners in cooler microclimates within Zone 9, such as those closer to the coast or in higher elevations, who have had more success with growing ranunculus as perennials.
To summarize, while ranunculus are technically perennials, their ability to return year after year in Zone 9 is somewhat limited. However, if you live in a cooler coastal area or a higher elevation within Zone 9, you may have better luck with establishing them as perennials. It is important to provide well-drained soil and protect them from excessive heat to maximize their chances of survival.
