To keep Erythronium flowers fresh for a long time, you should plant them in a location with partial shade to shady exposure. The soil should be well-drained and moist, but not wet. Water regularly during the growing and flowering period, but avoid waterlogging. After flowering, leave the plants alone so that they can store nutrients for the next flowering. Erythronium is relatively easy to care for, but a good location and adequate watering are important to maintain its beauty and vitality.