Heliotropes grow to heights of 1 to 2 feet and have clusters of sweet-smelling purple flowers nestled in deep-green leaves. It is a tender perennial, so is grown as an annual except for in more tropic areas that have warm winters. Heliotrope is usually planted from seed 12 weeks before the last expected spring frost in your area. The seeds are slow to germinate, taking up to a month before sprouting. Grow heliotrope directly in the garden bed or in a pot that you bring inside each fall to protect from winter cold.
Fill a 4-inch pot with soil-less seed starting mixture. Water the potting mix so it is moist but not soggy.
Sow four to six seeds directly on the soil surface, then lightly press them against the soil with your fingers. Not all seeds germinate, so over-planting each pot is necessary.
Cover the pot with a plastic bag and set in a 70 degree Fahrenheit room to germinate. Remove the plastic bag once seedlings emerge.
Move the seedlings to a sunny window or place under grow lights. Water as needed to keep the soil moist.
Thin the seedlings to one per pot once they produce their second set of leaves. Pinch off the weaker seedlings at the soil surface, leaving the strongest seedling in each pot.
Transplant outside once all danger of frost has passed. Plant in a well-drained, sunny garden bed.