Verbena seed germination times depend upon the variety, so don’t get discouraged. However, knowing how to grow verbena from seed will greatly improve the chances of sprouting. The seeds need well-draining soil in a good, sterile starting medium, light moisture and total darkness.
Overall, growing verbena from seed is easy and can save you money on your annuals.
When to Plant Verbena Seeds
Planning on the right time to sow seeds can make all the difference in the world between success and failure. If you plant too early, seedlings may die in overly wet or cold weather. If you plant too late, you may not get flowers before the growing season ends.
Verbena is cold tender and seedlings are even more prone to cold sensitivity. You may sow verbena seeds indoors 10 to 12 weeks before planting them out or wait until spring and plant them in a cold frame or raised bed. Just make sure there is no chance of frost. The actual month will vary, dependent upon your USDA zone.
Verbena seed germination can take as little as 20 days or up to a month or more and, in most cases, requires cold stratification in order to be successful. The seeds are variable, so be patient.
How to Grow Verbena from Seed
Use a well-draining, moist potting mix if starting seed indoors. Sow verbena seeds in compartmented flats. Place a few seeds in each compartment and thin them after germination. Verbena seed germination requires darkness. You can simply dust some soil over the seeds or cover the flat with black plastic.
In outdoor settings, wait until no freezes are expected and prepare a garden bed. Incorporate compost or other organic matter and rake the bed to remove any impediments, such as rocks or twigs. Sow seeds just as you would indoor plants.
Once germination takes place, remove black plastic if applicable. Wait until the first set of true leaves appears and then thin plants to 12 inches (30 cm.) or one plant per compartment.
Care of Verbena Seedlings
Harden off plants by giving them gradually longer exposure to outside conditions for a week. Once plants are used to the wind, light and other conditions, it is time to transplant them.
Transplant outside when temperatures have warmed and soil is workable. Space plants 12 inches (30 cm.) apart in full sun. Keep competitive weeds away from seedlings and keep the soil moderately moist.
Pinch plants back after a month to promote thicker, denser verbena. Deadhead regularly once plants begin to bloom to encourage more flowers. At the end of the season, save more seed to continue the easy beauty of verbena.