Blooming their hearts out for weeks and brightening the dullest days, Primroses and Polyanthus are some of the earliest flowering primulas. Highly popular in the spring gardens and containers, these cheerful perennial plants are incredibly diverse in size and come in almost every color imaginable. Some are wonderfully scented and terrific for attracting early insects. Reflecting their popularity, there are thousands of cultivars available. Highly versatile, they are perfect for containers, window boxes, or planted in groups at the edge of borders, in rock gardens, woodland gardens, or by streams and ponds.
- Primroses and Polyanthus include the English primrose (Primula vulgaris), cowslip (Primula veris), oxlip (Primula elatior), and the thousands of hybrids resulting from these species. Their vibrant and colorful flowers are either borne on individual short stems among the leaves (Acaulis type) or carried in long-stalked umbels (Polyanthus type).
- They usually enjoy a long flowering season extending from early to mid spring.
- They grow up to 12 in. tall (30 cm).
- They thrive and are almost indestructible if planted in fertile, humus-rich, moist but well-drained soil in full sun or partial shade. Make sure they sit in a partially shaded spot protected from the hot summer sun and the soil does not dry out.
- They require little attention, aside from division, every 2-3 years, in early spring or fall. If grown in pots, repot into fresh compost each year. Remove decaying leaves to reduce risk of fungal infections, discard old blooms to avoid rot in the crown.
- Feed them with a weak solution of high potash or tomato fertilizer every ten days from the time the buds start to form until the first flowers open.
- They should be sown or planted in early fall.
- They look fabulous by themselves and create impressive displays when planted en masse. But they also look great planted with companion plants. Plant them under deciduous shrubs, such as Acers (Maples), Viburnums, Philadelphus (Mock Orange), Hamamelis (Witch Hazels) or Rose shrubs. They will fully enjoy the spring sun before the shrubs unfolds their umbrella of leaves, and will be protected from the summer sun when the shrubs are in full leaf.
- Team them with spring-flowering bulbs such as Muscari (Grape Hyacinths), Narcissus (Daffodils) or Galanthus (Snowdrops). Combine them with Helleborus (Hellebores), Dicentras (Bleeding Hearts), Anemone nemorosa (Wood Anemones), Viola cornuta (Violets), Sedums or Sempervivums.