Primula seeds can be sown from late summer through to early autumn and again in late winter or early spring. It is best to use a peat based seed sowing compost in small pots or seed trays and sow the seeds thinly on the surface either leaving them uncovered or covering lightly with vermiculite. Moisten (but do not over-water) the compost and then cover the tray or pot with polythene or a small piece of glass to prevent drying out. Temperatures should not be allowed to exceed 20°C as this will inhibit germination. Primula seed normally germinates in about three weeks.
When the Primula seedlings are large enough, prick out into individual small pots and grow on for a further four to five weeks, by which time the plants should be ready to be moved into 9 cm pots. Primulas need an acid compost for best results, and an open texture is desirable to prevent waterlogging. Once the plants are growing strongly, feeding with a standard tomato fertilizer will help build strong healthy plants.
After about eight to ten weeks in the 9 cm pots the young Primula plants will be ready for potting on or moving into the garden. If planting out make sure the soil has a reasonable humus content and if in doubt dig in some well rotted organic matter before planting. It is best to choose a moist (not wet or boggy) and partially shaded area to get the most out of your Primulas but they will survive in full sun if moisture is freely available. These plants will thrive for at least three or four years but after that it may be worthwhile invigorating the stock by sowing fresh seeds or dividing the plants in the garden by lifting them and splitting the crowns into three or four small pieces. Division of Primulas is best done in early autumn, say September, and should never be attempted during hot dry spells.
Although Primulas thrive in cool moist conditions, good air movement is important to keep disease at bay. In the garden slugs and snails can be a problem as the pests like the same conditions as Primulas, so suitable control measures should be taken.
Return to the Owl's Acre Primula Seed page.
© 2009 Mark Rowland