Yes—it's extremely forgiving

Can I harvest comfrey leaves regularly

Berries are quite showy and will persist throughout the winter (hence the common name) and often into early spring

How do I prevent it from spreading

or cream flowers

100 Pale Evening Primrose Seeds Microbiota Decussata Yes—it's extremely forgivingHigh Quality Pale Evening Primrose Seeds: Grow Beautiful Oenothera pallida Flowers with Ease! The Pale Evening Primrose is a vigorous plant and begins blooming just two months after starting the flower seeds which is very unusual for a perennial. Better yet, it will continue to bloom all summer and into fall. Flower SpecificationsSeason: PerennialUSDA Zones: 3 9Height: 8 16 inchesBloom Season: Summer and early fallBloom Color: WhiteEnvironment: Full