HOW TO GROW LAVENDER FROM SEED
(1) [Optional] 12 WEEKS FROM FROST-FREE PLANTING TIME: Put the seeds through a process called "cold stratifying.” To optimize germination rates, place seeds between moist (but NOT soaking-wet) paper towels in a resealable plastic bag, and put this plastic bag in your refrigerator for three weeks. After three weeks, open the paper towel and plant the seeds following Step 2 below.
(2) 6-9 WEEKS FROM FROST-FREE PLANTING TIME: Lavender seeds take a while to germinate (sometimes as much as four weeks), so we recommend sowing seeds in trays indoors about 6-9 weeks before the traditional outdoor planting time (in northern climates, plant seeds indoors roughly late March or any time in the month of April). Use a commercially-sterilized soil especially formulated for starting seeds – never use soil you’ve taken from your garden, as it likely contains pathogens which will kill fragile indoor seedlings. Sprinkle the seeds on top of the soil. If using a plastic seedling tray, plant one seed per slot. If planting in a division-free container, space the seeds 1/2 to 1 inch (1.27 to 2.54 cm) apart. Gently press the seeds into the soil (no deeper than 1/8 inch).
(3) SOIL TEMPERATURE IS CRITICAL: For an optimum germination rate, keep the soil temperature around 21 degrees (C) [70F]. We recommend putting those seed trays on a heating pad, available from most garden supply centres or mail order (e.g. Veseys Seeds).
(4) LIGHTLY WATER THE SOIL. Keep the growing soil moist, but not damp, and water the seeds in the morning so that the soil can dry during the day. Soil that is too damp and cool will invite fungus to grow, and fungus will destroy your seeds.
(5) GIVE SPROUTED SEEDS PLENTY OF LIGHT. After the seeds sprout, move the seed trays to a location which receives plenty of direct sunlight. If no such location is available, place a fluorescent grow light above the sprouts and allow them to sit in the artificial light for eight hours a day.
(6) [Optional intermediate step] TRANSPLANT TO A SMALL POT. Once your plants have several pairs of leaves, it’s time to put them into a small- or medium-sized pot at least 2” (5 cm) in diameter, filled with general potting soil and a little bit of granular, time-release fertilizer (7-7-7, or any fertilizer containing balanced proportions of nitrogen, phosphorus, and potassium).
(7) FINAL STEP: Once your seedlings are about 3 inches (7.5 cm) tall, you can then “harden them” by placing them outside for increasing amounts of exposure to the outdoor environment. After all danger of frost has passed, the seedlings can be planted in the ground in well-drained soil with full sun.
(8) ADDITIONAL RECOMMENDATION: Lavender seedlings will develop into hardier, more attractive plants if you do not allow them to blossom the first year. Instead, pinch off the top part of each branch or blossom head. This will encourage vigorous root growth, as well as new branches will sprout from within the core of the plant, giving it a richer, fuller appearance. You can let your lavender fully blossom from the second year on. Enjoy!