|Centaurea montana 'Amethyst in Snow'|
|Centaurea montana 'Amethyst Dream'|
The Daily DuBrule
I am constantly being asked to give talks about Succession of Bloom in the Perennial Garden. I wrote a book about this subject, specific to Connecticut, tracking when plants bloom by variety. I did this because I was completely frustrated with the general bloom period descriptions in books and catalogs that are written for the entire country, not our state.
When plants bloom is key to an all-season, colorful garden. But when plants emerge is also important. April can be a tough month in the garden if you haven't invested in spring blooming bulbs or flowering shrubs. Many perennials are still dormant, or slowly emerging. You get so excited about the flowers of spring and just keep walking around your borders saying "come on, grow!" That is why I love plants that "bulk up" early. What that means to me is a plant that emerges with a strong crown of foliage and adds a good amount of greenery to the garden. Centaurea montana, also called perennial bachelor's buttons, fits that bill.
Ten years ago, I primarily grew the blue flowered form, the straight species. Always admired in the garden, it resembles a blue thistle flower. Then I found out about the pure white form. The real breakthrough came with 'Amethyst in Snow', pictured above. I was in love. What a gorgeous bi-color blossom! Last year, I got my hands on 'Amethyst Dream', a solid purple introduction. Purple is my favorite color and I was in heaven.
I like Centaurea montana because it is versatile. It will grow in sun or partial shade and in almost any kind of soil. The flowers begin blooming in late May and continue into mid to late June, giving me color when the May flowers are fading and then happily combining with the June bloomers. If you deadhead it, you will prolong the bloom. After all flowering is done, I cut the flower stalks right down to basal foliage. By then, there are so many other plants filling out the garden and blooming their hearts out that you don't miss this plant.
I use perennial bachelor's buttons under and near plants that take a long time to sprout and leaf out in the spring. Butterfly bushes, Caryopteris, ferns, hydrangeas, Eupatorium, Hibiscus, Asclepias are just a few of the plants that come to mind. It is a great design trick that keeps your garden full and lush every month of the growing season.