Rose Periwinkle
I really want to place a rosy periwinkle under a medium sized tree. It would receive dappled shade and 20-30 minutes of irrigation three days a week. Will it be too much shade and water for the plant?
Rosy periwinkle also known as annual periwinkle or botanically as (Catharanthus roseus) is a good choice for sun to part shade and droughty conditions. The shady conditions should be fine. Try a couple the first year and if they thrive you can always increase the planting area next season. Just limit the disruption and damage to the shallow tree roots. I am more concerned about the water that could harm both the periwinkle and your tree. Water thoroughly and less frequently for best results. Frequent watering can result in shallow roots that are more drought sensitive and subject to root rot. You may want to contact your irrigation professional and talk about adjusting the watering schedule to better fit the needs of your established trees.
