Some varieties give us a bright yellow summer, while others wait until fall to show off their blooms. But once winter hits, you won’t see a trace of life above the soil. Did they freeze to death? Not at all! These beauties are just resting, and we’ll be welcoming them back next year.
Winter Hardiness Varies Quite a Bit
All perennial sunflowers come back year after year, but they don’t all handle the cold the same way. When it comes to winter hardiness, we can generally group them into three categories:
- Hardy perennial sunflowers
- Frost-sensitive perennial sunflowers
- Non-hardy perennial sunflowers
To make sure your sunflowers make it safely into the new year, it helps to know exactly which variety you’re growing.
Hardy Perennial Sunflowers Can Handle Themselves
As long as their location gets at least five hours of direct sun during the summer, these plants aren’t too picky about winter. They can brave the frost all on their own.
One quick tip: stop fertilizing by September. This encourages the plant to stop putting out new growth and start hardening off, which minimizes the risk of frost damage. This is a good rule of thumb for all perennial sunflowers!
Frost-Sensitive Perennials Need a Little Help
Frost-sensitive varieties have “middle-of-the-road” hardiness. They can stay in the garden bed year-round, but they might not survive a harsh winter without a helping hand. To keep the deep freeze from reaching the roots, cut back all the stems close to the ground before the first frost. Then, tuck them in by covering the root area with a thick layer of mulch, fallen leaves, or mature compost.
Pro Tip:
As soon as the spring sun starts peeking out, clear away that layer of leaves. This allows the sunlight to hit the soil directly and warm it up for the new growing season.
Non-Hardy Perennials Need a Change of Scenery
Even non-hardy sunflowers can brighten up your garden for several years—it would be a real shame to let the frost take them! If they aren’t already growing in containers, overwintering them takes a little extra effort, but it’s totally worth it. You’ll just need a suitable winter spot:
- Dig up the perennial before the first frost.
- Plant it in a pot (standard garden soil works fine).
- Move it to a cool, frost-free place indoors.
- Water sparingly every now and then.
- Replant it back outside after mid-May (once the danger of frost has passed).
Note:
Many gardeners consider the Mexican Sunflower to be a true sunflower, though strictly speaking, it’s a close relative. Just keep in mind that it isn’t winter-hardy either and needs to be overwintered safely.
