What is a perfect plant? In my imagination, it’s a long-lived perennial that is easy to grow from seed, blooms the first summer, and self sows in moderation. Does this dream plant really exist? Probably not. But some first-year flowering perennials come pretty close to the ideal.
One of the neat things about first-year flowering perennials is you get to see blooms the same year that you start the seeds. Not only is this a rewarding experience, but it also lets you know if you planted it in the “right spot”. If the flowers end up clashing with their neighbors, you can move the plant to a new location before it gets too big.
Are there any disadvantages to first-year flowering perennials? My only complaint is they are not always long-lived. It seems like the most reliable plants are the ones that are difficult to start from seed and slow to begin blooming. For example, daylilies are long-lived. But they are challenging to grow from seed, and they take 2-3 years from seed to bloom. They rarely self sow in the garden, and when they do, they don't come true to type. Most first-year flowering perennials are easy to grow, and they reseed true to type, as long as different varieties of the same species are isolated from each other.
If you want to see blooms on your perennials in the first season, you need to start the seeds indoors 6-10 weeks before the last frost date. Of course, they will not bloom at their “normal” time the first year. For example, Lupine ‘Morello Cherry’ usually blooms in May. If you start the seedlings indoors in March, then transplant them outside after the last frost date, you can expect to see the first blooms any time from July to September. The following May, the show will be more spectacular.
Climate, soil and sun exposure affect bloom time and whether or not the perennial will flower the first year. If you live in a warm zone, or if you have good soil and plenty of sun, your plants will have an advantage. I live in zone 5, and most of these plants perform well for me.
First-Year Flowering Perennials