Tithonia Seeds - Mexican Sunflower

Minimum Seeds per Packet: 18

Packet Weight: 0.5g

Planting Season: After Last Frost

Sowing Method: Direct Seed

Seed Depth: Surface

Direct Seed Spacing: 4-8"

Soil Temperature: 70-80℉

Days to Sprout: 7-14

Mature Spacing: 12-18"

Sun Requirement: Full Sun

Frost Tolerance: Frost Sensitive

Days to Harvest: 80-90

Production Cycle: Annual

How to Plant Mexican Sunflower Seeds

Tithonia rotundifolia seeds should be barely covered with dirt since Mexican Sunflower seeds need light to germinate. Once the Mexican Sunflower seedlings are three inches tall, thin seeds to 12 to 18 inches apart for mature spacing. Without proper spacing Mexican Sunflower plants will not reach their full growing potential. Dead head and cut blooms often for thicker, sturdy plants. 

Plants may need to be staked and protected from wind, as these tall plants can become brittle and fall over when they reach their full height. Mexican Sunflowers often reseed themselves and come back year after year if the seed pods are left on the plant. Tithonia can be grown as a perennial plant in zones 9-11.

When to Plant Mexican Sunflower Seeds

Mexican Sunflower seeds can be directly sown outside after all danger of frost has passed in a full sun area. If you’d like to get a jump start on the growing season, you can start Mexican Sunflower seeds indoors six to eight weeks before the last frost. Once all danger of frost has passed, Mexican Sunflower plants can be planted outside in a well draining full sun area. 

Where to Plant Mexican Sunflower Seeds

Mexican Sunflowers are tall plants that do best in the back border of gardens so as not to shade out smaller plants. They can benefit from staking and wind protection, or being placed next to other tall plants such as other sunflowers for support. They like full sun and hot, dry locations with well-draining soil and little water. 

How Often to Water Mexican Sunflower Seeds

Tithonia rotundifolia are native to Central America and Mexico, so they prefer hot and dry locations with little water. It is important to keep them moist for germination, but once the seedling is established, it does not need very much water at all and should not be watered more than 1” a week.

What do Mexican Sunflower Seeds Look Like

Tithonia seeds are triangular in shape with a little crown on the wide end. 

How to Harvest Mexican Sunflower Seeds

Tithonia seeds will be ready to harvest once the seed pod after a spent flower is brown and dry. Cut these dry pods and collect them in a container or paper bag of your choice, as long as it is clean and completely dry. To separate the seeds from the seed pods, lay the pods out on a working surface. Wearing gloves while separating the seeds from the pod is recommended, as Tithonia seed pods can be very prickly. Squeeze, roll, and pull apart the pod until the seeds start to fall out on their own. You can separate the seeds from the chaff (the excess plant matter) by hand, but it is much easier to shake and blow into a container, or shake in front of a fan, to blow off the lighter material and the heavier seeds will stay in the bottom of the container. Collect these seeds and store in a cool, dry place for next season.