From our perspective as Cornflowers (Centaurea cyanus), we are sun-worshippers. We require a location that provides us with at least six to eight hours of direct, unfiltered sunlight each day. This abundant energy is crucial for building our strong stems and producing the vibrant blue, pink, white, or purple blooms we are known for. When it comes to soil, we are not demanding. In fact, we prefer to be left to our own devices in poor to average, well-draining soil. Rich, heavily amended soil can make us leggy and less likely to flower prolifically. The most critical factor for our roots is excellent drainage; we cannot tolerate having our roots sitting in soggy earth, as this will lead to rot. Please give us space to breathe and grow; plant our seeds or young seedlings about 12 inches apart to ensure good air circulation.
We are annuals, which means our entire life cycle—from germination to seed production—completes in a single growing season. The easiest and most natural way for us to begin is from seed. We are cool-season plants, so we prefer to be sown directly into your garden in the early spring, as soon as the soil can be worked. Some of us can even be planted in the fall in milder climates to germinate after the winter. Simply scatter our seeds on the prepared soil and lightly press them in, as we need light to germinate. There is no need to bury us deeply. With consistent moisture, we will sprout within 7 to 10 days. While you can start us indoors, we have sensitive taproots that dislike being transplanted, so direct sowing is always our preferred method.
Once we are established, we are remarkably drought-tolerant. Our deep taproots seek out moisture from well below the soil surface. During the initial growth period after germination, please keep the soil consistently moist to help our roots get established. After that, we typically only require watering during extended periods of dry weather. A good rule is to water us deeply when the top inch of soil feels dry. As for food, we truly thrive on neglect. We do not require, or even want, heavy fertilization. An application of a balanced, slow-release fertilizer at planting time is more than sufficient for our entire season. Too much nitrogen will encourage an abundance of leafy growth at the expense of our beautiful flowers.
Our primary goal is to flower and set seed to ensure future generations. You can help us produce more blooms through a practice called deadheading. Once a flower begins to fade, simply snip off the spent bloom just above a set of leaves. This signals to us that we need to produce more flowers rather than putting energy into seed production. If you would like us to self-sow for the following year, allow the last blooms of the season to mature and drop their seeds naturally. We are generally trouble-free when it comes to pests and diseases, especially if we have good air circulation. Occasionally, we may be bothered by aphids or suffer from powdery mildew, but these issues are rarely serious and can be managed with a strong spray of water or an organic fungicide if necessary.
