Growing showy primrose from seeds is easy. Keeping the plant from taking over the garden? Not so much.

The showy primrose (Oenothera speciosa) is a type of evening primrose that, because of its nickname is often confused with plants in the Primula genus. This primrose, however, blooms in soft pink flowers and spreads by runners, making it a lovely flowering groundcover.

A native wildflower, showy primrose seeds thrive in poor soil and has a number of uses, from filling a bare garden spot to being featured in a rock garden.

Therein lies the problem. Once planted, you may never be rid of it. Spreading via seed and runners, it will take over your garden.

Be that as it may, we write this tutorial for a longtime reader who has asked for it. 

Timing and Preparation

The best time to plant showy primrose seeds (you can buy them online, here) is in spring, when the air temperature reaches 65 degrees Fahrenheit. Choose the sunniest place in the garden and remove all weeds in the area.

Then, loosen the top 2 inches of soil with a gardening fork to allow the seedling’s roots to more easily penetrate the soil as they grow. There’s no need to amend the soil with compost as the showy primrose actually thrives in poor and even rocky soil.

The soil does need to drain freely, however, so if you have heavy clay soil, throw in a 3-inch layer of compost and mix it into the top 6 inches of soil. If you don’t make your own compost, try Michigan Peat’s Magic Compost, far superior to what you’ll find at the big box gardening centers.

 Seeding the Showy Primrose

Scatter the tiny showy primrose seeds across the surface of the soil and, since they require light to germinate, don’t cover them, but rake them lightly into the top one-quarter inch of soil. If you’re seeding a large area, mix the seeds with an equal amount of sand and use a hand-held broadcast spreader (available here) to spread the mixture evenly across the soil.

Water the seeds right after planting and keep them moist during germination. As long as the air temperature remains between 65 and 70 degrees Fahrenheit, the showy primrose seeds should germinate from within 20 to 45 days. The seedlings are very tiny so protect them from trampling by pets and kids.

Care of Showy Primrose Seedlings

Maintaining evenly moist soil during and after germination will ensure that the showy primrose plants get off to a good start. Be careful not to overwater them, but keep the top inch or two of soil slightly moist.

When the seedlings get their second set of leaves, fertilize them with all-purpose plant food, diluted to half the strength listed on the product’s label. If the weather is particularly warm at this time (over 80 F), wait until late afternoon or early evening to apply the fertilizer to avoid scorching the showy primrose seedlings.

When the plants reach three inches in height, remove the weaker seedlings, leaving 12 to 18 inches between those that remain.

 Additional Considerations

Since showy primroses are perennial, you won’t need to reseed the following season. In fact, toward the end of the blooming season, if you mow the plants to a height of 5 inches, they may come back and bloom again in late summer or early fall. After this bloom has finished, mow the plants to 3 inches in height and they’ll return the following spring when the weather warms. And the spring after, and the spring after and …

Looking for a non-flowering groundcover? Check out dymondia.

 

Feature photo Courtesy: By ZooFari (Own work) CC BY-SA 3.0, via Wikimedia Commons