When it comes to my favorite blue perennials, it didn’t take long to come up with the first one. The other two were a bit more challenging (there are so many great candidates) but I’ve selected several for you to try.
This perennial geranium is one of the longest blooming plants in my garden and this alone gets it first place. Starting in very early summer, it springs into a mass of violet-blue flowers and continues with this pace of blooming right to the very bitter, cold end of fall when winter sweeps across my garden.
- Grow it in the full sun or light shade for best blooming.
- Grows 12-18 inches tall if left to sprawl by itself. Will grow taller if crowded. I grow mine on the edge of the garden allowing it to hang over the raised beds down into the pathways. It would be a perfect plant to hang down over a wall.
- Grows 36-inches wide give or take a few inches.
- Propagation is by division in the early spring just as it is starting to grow.
How could I talk about my three favorite blue perennials and not write about growing Lavender?
Between the fragrance and the delightful flower spikes for a very long blooming season, this plant deserves a place of honor in my garden (and it gets it right beside the front door).
Grow in the full, hot sunshine. The hotter the better for this heat-loving perennial flower.
Grows 8-30 inches tall depending on variety but generally you’re going to see an 18-inch flowering plant if left uncrowded.
Grow in a well-drained soil (no clay) and shear the blooms after they are finished to promote a second flush of blooms.
Do not feed or water other than a shovel of compost in the early spring. The fragrance is much better if left alone.
Propagation is by tip cutting
You can get more info on growing lavender here along with a video
I had a lot of trouble deciding on the last one of three of my favorite blue perennials but had to finally pick the plant I’ve collected for a few years and the one that’s slowly taking more and more space in my garden as I add newer varieties.
Nepeta or Catnip
Ornamental catnip is again one of the full sun perennials that has to be included in this list. It’s a long-season bloomer that lasts from mid-summer until late fall in my garden. While I’m not overly fond of the fragrance, I’m enchanted with the blooming.
Grow this is the full sun or very light shade. It will get powdery mildew or botrytis if it doesn’t get enough sunshine.
Growth to 18-inches depending on variety and at least 24-30 inches wide.
You can propagate it by cuttings or an early spring division to get even more for your garden.
As a note – if your Catnip isn’t cut or bruised, cats won’t bother it at all. But as soon as you bruise a leaf or cut it to release the fragrance, you’re going to have visitors.