How to Collect Verbena Seeds
Dainty little verbena flowers may look delicate, but they're tough little annuals that love sunshine and won't mind a few dry days. They're versatile plants that do well as a ground cover, edging a flower bed or a sidewalk, or in a container or hanging garden, spreading out and blooming from late spring to the first freeze. Although verbena are readily available as bedding plants, consider starting new plants with seeds you've collected.
Leave a few healthy verbena blooms to die naturally on the plant. As the flowers fade, they will be replaced by light brown clusters that develop on top of the stem.
Pinch the clusters off the plant and let them drop on a paper plate. Put the paper place in a dry, cool spot and let it dry for a week to 10 days.
Rub the dry cluster between your fingers, and the tiny, off-white or tan seeds will separate from the dried plant matter, or chaff.
Label a paper envelope or a small paper bag. Drop the seeds in the bag, along with the chaff. Put the seeds in a cool, dry place until spring.
Purple Verbena Seeds
Well suited to U.S. Department of Agriculture plant hardiness zones 7 through 11, purple verbena seeds can be purchased through online or mail order stores and in retail nursery and garden centers. Seeds generally come 50 to a package, and can also be purchased in bulk. You can also harvest the seeds from your existing plants. The seeds should be planted about three months before the last frost, in temperatures ranging between 70 to 75 degrees Fahrenheit. Because seeds need darkness to germinate, sow them at least an inch deep, then lightly cover them with soil. If nighttime temperatures drop below 50 degrees Fahrenheit, cover the seeds with black plastic overnight to retain some of the daytime heat. Allow the soil to dry out between waterings. A drip system is preferable to an overhead watering system, to keep water off the foliage to prevent mildew, particularly in dense beds with little air circulation.