When Should Sunflowers Be Harvested For Their Seeds?

Sunflower seeds are harvested when the large heads begin to droop and turn down, the backside of the head turns yellow-brown, and the tiny petals covering the developing seeds have dried and fallen off. If most of the petals are still attached, leave the sunflower alone. The seeds are hardened and turn black with white stripes, and the foliage has turned yellow.

Harvesting sunflower seeds is important as it can result in small and tasteless kernels, as well as birds and other wildlife beating you to the harvest. Some sunflower varieties mature faster, and it’s best to plant them directly into the ground or a large outdoor container/box once there’s no chance of spring frost returning and the soil is warmed to 50 degrees F.

Sunflowers brighten your garden for several weeks in summertime, about 80 to 140 days after you sowed the seeds, depending on the cultivar. After that, they hang. Once the sunflowers have died back completely and the backs of the blooms are brown, it’s time to harvest. The seeds are plump and somewhat loose, and you should cut the stalk with sharp scissors or pruners about one foot down from the flower head and place it in a container that can catch any loose seeds.

One method for harvesting sunflower seeds is to allow the seeds to fully ripen on the stem, which could happen at any time of the year from July to October, depending on your growing zone, chosen cultivar, and sowing date. Ripe seeds should be plump and well-formed, and they should separate easily from the flowerheads as you work.

Many single-stem sunflower varieties are quick to bloom, needing just 60 days from the seeding date to reach harvestability. Harvest at the right time is crucial, as the seeds should be plump and developed, and the flower petals begin to dry out and fall off.