From our perspective as Nerine bowdenii plants, our relationship with the sun is one of nuanced craving, not simple gluttony. Our ancestral home is the rocky, well-drained hillsides of South Africa. This has conditioned us to thrive in conditions that many other so-called "full sun" plants might find challenging. We do not desire the harsh, all-day, scorching overhead sun that bakes the soil and stresses our bulbs. Instead, we perform our best with what you might call "bright, cool sunshine." Our ideal is a location where we receive a minimum of six hours of direct sunlight, but we have a strong preference for the gentler rays of the morning sun. This energizes our photosynthetic processes perfectly, preparing us for the day.
You must understand that our growth cycle is opposite to many garden bulbs. We send up our tall, sturdy flower stalks in the late summer or fall, often before our strappy, green foliage appears. This autumnal bloom is entirely dependent on the energy we stored in our bulbs from the previous growing season. That storage is a direct result of ample sunlight on our foliage during the spring and early summer. After we finish blooming, our leaves emerge and persist through the winter and spring, gathering sunlight. If we are planted in too much shade during this crucial period, our leaves will become weak, floppy, and pale. We cannot manufacture enough sugars, resulting in a weak bulb that may refuse to flower the following fall. Sunlight is the currency we use to buy our spectacular blooms.
Our sun needs must be interpreted through the lens of your local climate. Across the diverse regions of the USA, the intensity and duration of sunlight vary dramatically.
In the cooler Pacific Northwest (USDA Zones 7-9), we happily tolerate and even desire a full day of sun. The light is often filtered by clouds, and temperatures are moderate, meaning there is little risk of our bulbs overheating or our foliage scorching.
In hot-summer regions like the South, Southwest, and Southern California (Zones 8-10), the intensity of the afternoon sun is our adversary. Here, a position with morning sun and afternoon shade is not merely a preference; it is essential for our survival. The brutal afternoon heat can scorch our leaves and overheat our bulbs, putting us under immense stress.
For gardeners in the Northeast and Upper Midwest (Zones 6-7, with winter protection), your summers are shorter but can still be quite bright. A full sun to very light afternoon shade location is typically ideal, ensuring we get maximum light during the critical growth period without the extreme stress found in deeper south zones.
Our sunlight requirements are inextricably linked to another vital need: perfect drainage. We are utterly intolerant of "wet feet." A sunny location means the soil dries out more efficiently after rain or irrigation. Planting us in a shady, damp area is a certain path to bulb rot and our eventual demise. The sun helps keep the crown of our bulb and the soil around it warm and dry, conditions we find absolutely essential. Therefore, the sunnier the spot (within our defined tolerances), the happier and healthier we will be, as long as our roots are in the free-draining soil we require.
