I found this ancient Helium article on one of my all time favorite annuals, the pretty as you please Bachelor Buttons, and thought I may as well post it here for you.
Bachelor Buttons or Centaurea Cyanus as they are known botanically is an annual. It grows in all zones self-sowing to its heart’s content. Some call it the cornflower because of its tendency of frequently popping up in and around the borders of corn fields. In some areas they have become a wild flower and make a nice addition to any meadow with its traditional blue flowers.
The more common seed mixes on the market contain flowers in pink, burgundy, white and rose colored flowers as well as the blue. If allowed to hybridize on their own the blue will not produce a true seed . That is to say the blue color might be supplanted by the other colors if the bees pollinate all of them together. If you wish to collect your own seed and to have a ready supply of seeds that produce the distinct and coveted blue cornflower try to keep them away from Bachelor Buttons of other colors. Plant them in opposite ends of the yard might help. Perhaps the bees will cooperate. If you end up with all colors but blue you’ll have to try again and buy the only blue varieties.
Bachelor Buttons got their name when they were frequently used as boutonnieres. These pretty plants grow from 1 to 2 ½ foot tall. It branches nicely if given enough room. It has narrow 2-3 inch long, green, gray-tinged leaves. Flowers are 1 -1 ½ inches across . They generally have no fragrance but the butterflies like to settle themselves down on them and the bees are always buzzing happily around for the nectar.
The Bachelor Button likes any average garden soil and is quite drought tolerant. They like a less acidic soil so add a bit of lime where you want to plant these unless you know your soil’s pH level. They make a great addition to a cut flower arrangement lasting relatively long. As with all annuals, snipping off flowers at intervals will prevent the plant from going to seed too quickly and will promote more flowering. Caring for the Bachelor Button couldn’t be easier. Feed with a mild fertilizer or your own homemade compost tea as you would your other annuals and perennials.
One of the more popular and widely available Bachelor Button in garden centers and nurseries is “Jubilee Gem” with deep blue flowers. It comes in a bushy plant about a foot high. The very popular “Polka Dot” strain comes in all the usual cornflower colors. These are sold mostly in seed form.
One plant which technically isn’t a Bachelor Button though it is often mistakenly called such is Centaurea Montana. This one I highly recommend for the superior flower size and color and that you don’t have to replant it every year makes it that much more welcome. This one is actually a perennial which needs to be divided ever two years to keep it happy. You can easily find this on sale in most good quality garden centers, Home Depot or Lowes. The bushy plant grows 1 ½- 2 feet tall and wide. It has seven inch long grayish-green leaves and the flowers are a whooping 3 inches across. They even look as pretty when they are all gone to seed as they do freshly opened.
The seeds of the Bachelor Buttons should be sown in early spring but those seeds that were left behind in the garden over winter will readily sprout all on their own. In mild winter areas a late summer or fall sowing is fine. I’m certain you can find a nice place to put this curious, unassuming little plant. It has long been a childhood favorite for meadow bouquets picked especially for Moms all over the country. Here’s hoping you can pick your own by the next growing season.