Why Are My Primroses Blooming in the Fall?

If your primroses are putting on an unexpected show right now, you’re not the only one seeing these surprise blooms! What’s happening is a little plant trick called photoperiodism—basically, it’s how plants know when to flower based on the length of day and night. Typically, primroses are considered long-day plants, so they usually bloom in spring when the days are getting longer. But here’s the twist: sometimes, when the day lengths and temperatures in fall are just right, they get “confused” and think it’s spring again. That’s when you’ll see what’s called remanent flowering or secondary flowering.

 It’s not just primroses, either. I have seen a few autumn blooms on a couple of my rhododendrons this fall. They get the signal that it’s time to bloom again, even if it’s not their usual season. So, while those surprise flowers are a lovely treat, keep in mind that this second bloom can use up some of their stored energy, leaving them a bit less vigorous when spring rolls around.

 To help your primroses bounce back strong, give them a little extra love with some mulch now, though don’t bury the crown. In the early spring, give them a light dose of fertilizer. That way, they’ll have everything they need to put on their best spring show next year! 💚

Leola Young (with AI assistant)