Although members of the Primula genus are hardy or half hardy perennials they are frequently grown as annual in the garden.
They are a large genus and therefore have a large range in height of between 7 and 90 cm; most garden grown Primula are below 30 cm.
The time of years that Primula blooms in is species dependent and ranges from late in winter through to summer.
Primula are rosette plants and may have flat, tubular or bell shaped flowers.
As they love moist soil Primula are great little plants to grow in boggy areas, as well as in borders or in rock gardens.
Some common names for Primula genus members include Primrose, Cowslip, English Primrose, Fairy primrose and Polyanthus.
Primula by Hello-Julie.
Common Names: Primrose, Cowslip, Oxlip, Auricula. Primrose: German; English; Scottish; Arctic; Snowy; Anise; Northern; Burma; Ruby mountain; Fairy; Giant.
Life Cycle: Hardy perennial or half hardy perennial commonly grown as a half hardy annual by gardeners.
Height: 2 to 36 inches (5 to 90 cm).
Native: South America, Europe, Asia, Northeast Africa.
Growing Region: Zones 3 to 10.
Flowers: From the end of winter, through spring and/or summer.
Flower Details: Purple, white, pink, yellow, red. Bi-coloured. Flat. Bell-shaped. Tubular. Sometimes clustered.
Sow Outside: Surface. Autumn (warm areas). Spacing 5 to 20 inches (12 to 50 cm).
Sow Inside: Mix seeds in a growing medium, place in a freezer bag, keep moist, then stratify by refrigeration for three weeks. Germination time: one to six weeks in the light. Temperature 60°F (16°C). Two months before expected last frost. Transplant outdoors following the last frost.
Requirements: Partial shade; full sunlight in cold areas. Good drainage. Soil pH 5.5 to 7. Humus rich soil. Moist soil. Cool soil. Feed once during vegetative growth period. Perennials should have their stems cut back following flowers and given a summer mulch to keep roots cool. Propagate perennials by dividing in the autumn.
The primrose seeds should be sown on the surface in the autumn. As they are difficult to grow from seed in many areas you may prefer to use plants bought from a garden center; plant these out following the last frost of spring.
In both cases small varieties of Primrose should be spaced about 15 to 20 cm apart; and larger Primula varieties about 40 cm apart.
Primrose prefer a partially shaded area of the garden but may require a fully sunny area in colder regions. The soil should be moist and humus rich, with very good drainage and a slightly acidic to neutral pH (5.5 to 7).
When starting off primrose from seed indoors do so about 2 to 3 months in advance (with a view to transplanting them outdoors after the last frost of spring).
The seeds should be mixed into soil and put in a plastic bag. Put the bag in the fridge for 20 days. The Primrose seeds should then be moved into the light (out of the plastic bag) and germinated at 15 to 18 degrees centigrade; this should take from two to six weeks.
It is fairly easy to look after primrose, Cowslip and other Primula members. They have a preference for a cool soil so it is good to supply a mulch before summer.
Primula should be fed with a non-organic fertiliser just before flowering. Following flowering remove stems and top dress the soil that Primrose grows in with peat moss.
If you require more Primula plants then they can be propagated by division.