Tender Perennial vs Perennial
Not all perennials are created alike. If you live in planting zones 3 - 6 (aka growing zone or hardiness zone), some perennials (true, hardy) will do just find buried in snow while others (tender) will perish once the temps drop. The key difference between tender perennials and perennials lies in their ability to withstand winter conditions: tender perennials will not survive cold winters, while true perennials can.*
Perennials
These plants are hardy and can live for many years, returning each season. They are resilient enough to endure winter conditions and can be used in various garden settings, including flower beds, borders, and cutting gardens.
Tender Perennials
While these plants can also live for multiple years, they cannot survive frost or temperatures below freezing temps. To protect them, they need to be kept in frost-free environments during winter or moved outside only after the frost risk has passed. Although sometimes referred to as annuals for simplicity, tender perennials are not true annuals, which complete their life cycle in one year. Many gardeners choose to treat tender perennials as annuals.
Tender perennials often originate from warm climates, and require nutrient-rich soil and ample water. To overwinter them indoors, it’s best to place them in a warm, bright location, such as a sunny windowsill or under a grow lamp. Some plants can be stored in a cool place away from light so they can go dormant (do your reading on your particular plant before trying this).
*Most hardy perennials can tolerate temperatures at or just below freezing, but there are some exceptions:
Newly emerged growth: New growth on perennials can tolerate temperatures in the low 30s and upper 20s Fahrenheit, but can be damaged if temperatures drop into the lower 20s or teens. It can’t hurt to cover these parts of plants (or the entire plant, if size allows) with frost cloth during the coldest weather.
New plants: New perennials from a greenhouse may not be hardened enough to withstand a frost. Fall is a great time to plant perennials, but if you plant too late in autumn, your plant may not have enough time to establish itself, reducing its chance of surviving freezing temps.
Sudden cold snaps: If a sudden cold snap is forecast after planting, you can cover perennials overnight or for the duration of the cold snap.
Plant species: The extent of damage depends on the plant species. PLEASE always check the plant tag for the planting zone!
Exposure: The extent of damage depends on the plant's exposure.
Stage of growth: The extent of damage depends on the plant's stage of growth.
Knowing your planting zone and what type of perennial you have will help you take care of it and ensure great growing results.
