If annuals live one year or less and biennials live two years or less, then how long does a perennial live? When provided the proper growing conditions, a perennial can live several years or more in the garden. It starts its growth during the first year and flowers by the second year.
The biggest misconception about these plants, though, is that they'll live forever. "When people go to the garden center, they often don't ask how long this perennial is going to grow. They pick things out that have lots of wonderful flowers, and a lot of plants are not necessarily going to live a long time," says gardener Kathleen Nelson.
There are some perennials, however, that are legendary for their long floriferous lives. Peonies can live more than 100 years of blooming beauty. They reliably come back year after year.
Sometimes a plant will die after just a few years in the garden. Although it may be at the end of its lifespan, there may be another cause for its demise. Pests, such as burrowing rodents, deer or insects, could be the culprit. In some parts of the country, voles are common mouse-like pests. They're voracious vegetarians that move around underground, eating plant roots and destroying garden plants.
To make sure your perennials don't wind up being annuals, find the right place for each plant when adding them to the garden. That means replacing plants the voles eat with plants they'll leave alone, but it also means meeting the proper cultural requirements. After all, even the toughest perennial can't survive in living conditions. Here are some things to consider when planting perennials.
Consider the soil type and annual rainfall. "You need to know how much moisture you soil has and the amount of rainfall your area normally receives. Then plant the appropriate plants so that they'll survive," says Kathleen. Most perennials prefer well-draining soil with high organic matter content. Keep plants well-watered and provide supplemental water until newly planted plants are established in the garden.
Determine how much sunlight your perennials need. Some grow best in full sun while others do best in shady conditions. Full sun means at least six hours a day; full shade is less than three hours of sunlight. Partial sun or shade calls for three to six hours of sunlight daily.
Know your USDA hardiness zone. Consider the gardening climate when selecting perennials for your garden. The cold temperatures in the winter and the heat in the summer affect how long-lived plants are.
Provide maintenance as needed. The bloom period of many perennials is generally only a couple of weeks long, which means minimal deadheading. Occasional pruning or dividing is sometimes necessary too, but the result is a plant that looks great longer.
The truth is that your perennials will die at some point. But if you meet their cultural requirements and give them minimal care, odds are they'll grow beautifully for many years to come.