Seed Germination Database



Alcea rosea: Single Red Heirloom Hollyhock  Sowing Instructions: Best if direct sown in the garden where they are to grow. Can also be sown indoors 6-8 weeks before the last frost date. Use good quality seed starting mix. Plant the seeds 1/8” deep and moisten. Germination should occur in 10-21 days. (perennial)

Amaranthus caudatus: Love-Lies-Bleeding — Sowing Instructions: Sow indoors 4-6 weeks before the last frost date in your area. Barely cover the seeds and use caution when watering so as to not cover the seeds with soil. Let the plants grow and harden off a bit before planting outdoors. Seeds can also be sown outdoors. Just be sure to do so after last frost. Seeds should germinate in 10-14 days. (annual)

Aquilegia vulgaris ‘Magpie’ or ‘William Guiness’: Columbine ‘Magpie’ or ‘William Guiness’ — Sowing Instructions: Sow indoors 10-12 weeks before the last frost date. Sow seeds on the surface of good seed starting soil. Cover lightly with mix and moisten. Place in a plastic bag at 68-70°F for 1 week, and then in a fridge for 30 days. Move container back to 68-70°F. Germination should begin in 10-30 days. (perennial)

Asclepias tuberosa: Butterfly Weed or Pleurisy Root — Sowing Instructions: Best if sown outdoors after the cold frosts of fall have started. If sowing indoors, or in the spring, refrigerate the seed for 2 months before sowing. (The cold treatment will help break dormancy.) Sow seeds about ¼” beneath the surface. Germination will be irregular. (perennial)

Billardiera longiflora: Purple Apple Berry Vine — Sowing Instructions: Sow seeds about 1/16” deep in seed starting soil in a container just before the last frost in your area. May take up to a year to germinate but hopefully not. Leave in place or else move to somewhere protected during the winter like a greenhouse or coldframe. Be sure to keep the soil moist. (perennial vine)

Calycanthus occidentalis: Western Sweetshrub —  Sowing Instructions: Needs warm stratification followed by cold (several months each); germination occurs during second warm stage. Sow seed 3/8” deep, tamp the soil and mulch the seedbed if necessary. Warm stratify for 90 days, cold stratify in a fridge—or outside—for 120 days, then return to a warm 65°-75°F. (hardy shrub or small tree)

Campanula medium var. calycanthema: Canterbury Bells — Sowing Instructions: Sow outdoors anytime during the spring or the fall. Indoors sow 10-12 weeks before the last frost date in your area. Sow seeds on the surface of good seed starting soil. Place at 60-70°F. Germination should occur in 14-21 days. Does not flower the first year. Flowers the second year. Save some seeds and sow them next year so that you’ll never be without blooms. (biennial)

Canna indica: Wild Canna Lily — Sowing Instructions: Nick seeds with nail clippers. Once nicked, soak seeds for 2-4 days. You’ll soon see white poking out of the area where you scarified the seeds—these are taproots. (Soaking isn’t necessary but it will speed up germination.) Once done with the soak, sow seeds 1” deep in prepared pots with quality potting soil. Moisten soil and place in a well-lit area away from freezing temps. Don’t let the soil dry out, and don’t overwater. Green shoots should appear in 5-7 days. (tender perennial)

Capnoides sempervirens: Pale Corydalis — Sowing Instructions: Sow indoors 8 weeks before last frost date in your area. Barely cover the seeds in seed starting material. Sow at 68-72°F. Germination should occur in about 16 days. Can also be planted outside where you’d like for them to grow and bloom. (biennial)

Citrus trifoliata or Poncirus trifoliata: Hardy Citrus Tree — Sowing Instructions: Moisten a handful of clean, washed sand. Remove any excess water after placing into a sealable plastic bag. Push the seeds into the sand and seal the bag. Place in a refrigerator for 1 month. After, place seeds in pots with clean seed starting medium. Plant 1/4″-1/2″ deep. Place pots in a warm area, or use a seed heating mat. Seeds will germinate in 7-14 days. Allow the seedlings to grow 6 inches indoor until placing outdoors. (tender perennial tree)

Dianthus barbatus: Sweet William — Sowing Instructions: If sown in autumn, a few plants may bloom in spring. Most will grow and then bloom in a year. Best sown in rich garden soil where they’re intended to grow. If seeds are sown in ideal conditions in a sunny location the plants will reseed themselves and bloom again from year to year. Plant seeds 1/16” beneath the soil in a sunny location once the soil has warmed up in late spring. Germination should begin in 14-30 days. (Can be sown in outdoor pots too.) (biennial)

Digitalis purpurea: Common Foxglove — Sowing Instructions: Sow indoors eight weeks before the last frost date in your area, or outdoors after lost frost date. Sow seeds on the surface of moist seed starting soil.  (If sown indoors, seeds should sprout at room temperature after a few weeks.) Later plant out 12” apart in full sun and ordinary well-drained garden soil. (biennial)

Eccremocarpus scaber ‘Pink Lemonade’: Chilean Glory Vine ‘Pink Lemonade’ — Sowing Instructions: Considered a perennial is USDA Zones 9-10, in colder zones it is an annual. Start seeds directly outdoors in a prepared seedbed. In colder zones, seeds can be started indoors 6-8 weeks before last frost. Surface sow and cover with a thin layer of vermiculite. (tender perennial or annual)

Echium russicum: Viper’s Bugloss — Sowing Instructions: Sow on the surface of seed starting soil and cover thinly. Gently maintain constant moisture but don’t let the soil become wet. Keep at about 68°F until germination.  (Seeds should germinate quickly.) Keep in cooler conditions after germination.

Euphorbia lathyris: Gopher Spurge — Sowing Instructions: Soak in warm water for 2 hours before sowing. Euphorbia don’t like to be transplanted so it’s best to sow them where they’re to grow or use deep pots or plugs. Keep at room temperature and seeds should germinate in 2-3 weeks, but some may take several months. (biennial)

Heracleum maximum: Cow Parsnip — Sowing Instructions: Seeds should be sown into peat pots in the autumn. Sow where they’re going to grow. If sowing in spring, sow seeds in pots, wrap in a plastic bag, then stratify in the refrigerator for 3 weeks. Place outdoors. Once seedlings emerge, remove the covering. Transplant them to where they’ll grow. (biennial)

Lunaria annua: Money Plant — (both the standard and variegated) — Sowing Instructions: Plant after last frost in situ in a location that receives plenty of sunlight. Plant ½” (13mm) deep. Germinates in 10-20 days. Will flower the second year.  Plant annually for ongoing blooms. (biennial)

Mirabilis jalapa: Four O’Clock Flower ‘Red’ — Sowing Instructions: Sow between 65-75° with light if done indoors. Can also be planted outdoors where they’re intended to grow after the last frost in your area. Seeds should germination in about 14 days. Be sure to plant somewhere where they’ll get lots of sunlight and heat. (tender perennial or annual)

Rudbeckia hirta: Black-Eyed Susan — Sowing Instructions: Can be sown outdoors 2 weeks before last frost date. Sow on the top of the soil. Seeds should germinate in 2-3 weeks. Indoors, start 6-8 weeks before the last frost date. Sow on the surface of moist seed starting soil and keep at 70-75F. For best results, keep in a plastic bag and give plenty of light. Remove the bag when seeds begin to germinate. (perennial)

Seseli gummiferum: Moon Carrot — Sowing Instructions: Sow at 68°F just under the surface of damp seed starting soil mix. If no germination occurs after 4-6 weeks, move to 24-39°F for several weeks. Can also be planted in the garden where they’re intended to grow. Sow 2-4 weeks before the last frost date in your area. (biennial)