Prism™ Sunshine Petunia

Prism™ Sunshine is an annual grandiflora petunia with extra-large, showy bright yellow flowers and a mounding habit. Syngenta describes it as an early-flowering, traditional upright petunia and lists it for full sun. It flowers in mid-spring and summer and reaches 12–15 inches tall and wide. ([Syngenta Flowers](https://www.syngentaflowers.com/ams/product/flower/70002872)) ## Placement Grow Prism Sunshine in full sun and use it in packs or seasonal beds, where the bright yellow flowers can be repeated for a clear color block. The flowering period spans mid-spring and summer. ([Syngenta Flowers](https://www.syngentaflowers.com/ams/product/flower/70002872)) ## Establishment Acclimate young bedding plants outdoors before planting. Iowa State recommends hardening bedding plants for 7–10 days and notes that petunias can be pinched back to encourage branching. ([Iowa State University Extension](https://yardandgarden.extension.iastate.edu/how-to/selecting-hardening-and-planting-bedding-plants)) ## Maintenance During establishment, thoroughly water seedlings when the soil surface becomes dry. Remove flowers on blooming annuals during establishment to help plants settle in, as Iowa State advises.