Annuals are the quintessential filler plant. Although they only live for one year, they are well worth the effort of planting. Annuals bulk up quickly, generally flower continuously through spring and summer, and are perfect for planting in containers or in the ground. Not all annuals are easy to start from seed, however. The following varieties will give you a lot of bang for your buck. From one packet of seeds you could easily end up with enough plants to give your garden eye-catching color from top to bottom for months. Learn more: Growing Annuals in the Garden.

Calendula

Name: Calendula officinalis and cvs. (photo above)

Size: 14 to 24 inches tall and 12 to 18 inches wide

Days to germinate: 7 to 14

Germination conditions: Direct-sow seeds in spring after the last frost, and cover with ¼ to ½ inch of soil.

Growing instructions: Plant in full sun and in moist, well-drained soil. Space 6 to 8 inches apart.

Seed note: Let the flower heads dry on the plant. Rub them between your fingers to extract the seeds. Allow them to air dry for a week before storing.

 

Morning glory

Name: Ipomoea purpurea* cvs.

Size: Climbing to 6 to 10 feet

Days to germinate: 5 to 20

Germination conditions: Nick the seeds and then soak them overnight prior to sowing. Direct-sow after all danger of frost has passed, or start indoors on the soil surface four to six weeks before the last frost.

Growing instructions: Plant in full sun and in well-drained soil; rich soil promotes foliage but few flowers. Space 15 to 18 inches apart.

Seed note: Seeds are poisonous—do not ingest. Allow the seed capsules to dry on the vine; break them open, and lay them out to dry for a week before storing. Or let the plant self-sow.

Annual sweet pea

Name: Lathyrus odoratus cvs.

Size: Climbing to 6 to 9 feet

Days to germinate: 3 to 5 when soaked; otherwise, 10 to 21

Germination conditions: Sow indoors two months before setting out, or direct-sow in spring after all danger of frost has passed.

Growing instructions: Plant in full sun and in rich, well-drained soil. Space 4 inches apart, and do not transplant.

Seed note: Scarify the seeds and then soak them overnight prior to sowing.

Cosmos

Name: Cosmos bipinnatus cvs.

Size: 4 to 5 feet tall and 18 inches wide

Days to germinate: 7 to 14

Germination conditions: Start indoors five weeks before the last frost, or direct-sow after the last frost. Sprinkle soil lightly over seeds.

Growing instructions: Plant in full sun to partial shade and in consistently moist soil. Space 12 to 15 inches apart.

Seed note: To harvest the seeds, allow the cone-shaped seed heads to dry on the plant. Remove the seed heads and then roll the seeds out. Dry the seeds for a week, then store.

Heliotrope

Name: Heliotropium arborescens cvs.

Size: 18 to 24 inches tall and wide

Days to germinate: 15 to 20

Germination conditions: Start seeds indoors 10 to 12 weeks before the last frost. Sow on the soil surface.

Growing instructions: Plant in full sun and in rich, well-drained soil. Space 8 to 20 inches apart.

Seed note: Seeds are very small, so mix them with fine sand for even sowing.

Bells of Ireland

Name: Moluccella laevis

Size: 24 to 36 inches tall and 10 inches wide

Days to germinate: 25 to 35

Germination conditions: Direct-sow on the soil surface in spring after all danger of frost has passed. Seeds can also be started indoors eight to 10 weeks before the last frost.

Growing instructions: Plant in full sun to partial shade and in well-drained soil. Space 12 inches apart.

Seed note: Keep seedbed evenly moist during germination. The plant self-sows readily.

Scarlet runner bean

Name: Phaseolus coccineus

Size: Vining to 15 feet

Days to germinate: 10 to 15

Germination conditions: Direct-sow after the last frost, and cover with 1 inch of soil.

Growing instructions: Plant in full sun and in fertile, evenly moist soil.

Seed note: Harvest the seeds when the pods turn brown on the vine. Dry in a warm location for a week; shell the seeds from the pods, and store.

Pincushion flower

Name: Scabiosa spp. and cvs.

Size: 24 to 40 inches tall and 8 to 36 inches wide

Days to germinate: 10 to 15

Germination conditions: Direct-sow in spring after all danger of frost has passed, and cover seeds with 1/8 inch of soil. Sow indoors four to six weeks before the last frost.

Growing instructions: Plant in full sun and in well-drained soil.

Seed note: Allow the plant to self-sow, or collect the dry seed heads. Dry the heads for a week, remove the seeds, and store.

English daisy

Name: Bellis perennis and cvs.

Size: Up to 8 inches tall and wide

Days to germinate: Up to 21

Germination conditions: Direct-sow in fall, or start indoors six to eight weeks before the last frost. Cover seeds with ¼ inch of soil.

Growing instructions: Plant in full sun to partial shade and in light, well-drained soil. Provide regular water. Space 3 to 6 inches apart.

Seed note: To harvest the tiny seeds, cut off the flower heads when they are dry but before they shatter and self-sow.

Lobelia

Name: Lobelia erinus cvs.

Size: Up to 6 inches tall and wide

Days to germinate: Up to 21

Germination conditions: Start seeds indoors 10 to 12 weeks before the last frost. Do not cover
the fine seeds with soil.

Growing instructions: Plant in full sun to partial shade and in light, well-drained soil. Provide regular water. Space 12 to 15 inches apart.

Seed note: Do not save seeds—most are sterile.

Marigold

Name: Tagetes spp. and cvs.

Size: Up to 3 feet tall and wide

Days to germinate: 3 to 10

Germination conditions: Start indoors three weeks before the last frost, or direct-sow in spring when the soil is warm. Indoors or out, cover seeds with ¼ inch of soil.

Growing instructions: Plant in full sun and in well-drained soil.

Seed note: To harvest, cut off the dry flower heads and rub them between your fingers. Separate the seeds from the chaff, and spread them out to dry for a week before storing.

Love-lies-bleeding

Name: Amaranthus caudatus and cvs.

Size: 3 to 5 feet tall and 2 to 3 feet wide

Days to germinate: 10 to 15

Germination conditions: Direct-sow in spring after the last frost, or start indoors eight to 10 weeks before the last frost. Indoors or out, cover with ¼ inch of soil.

Growing instructions: Plant in full sun and in well-drained soil. Space 24 inches apart.

Seed note: This is an aggressive self-sower. Seeds can be saved by shaking the dried flowers into an envelope or other container.

Salpiglossis

Name: Salpiglossis sinuata cvs.

Size: 1 to 2 feet tall and 1 foot wide

Days to germinate: 10 to 14

Germination conditions: Sow indoors six to eight weeks before the last frost, or direct-sow outdoors after the last frost. Rather than cover the seeds with soil, place dark plastic over the flat or planting bed to exclude light; uncover when the seeds germinate.

Growing instructions: Plant in full sun and in moist, well-drained soil. Space 6 to 8 inches apart.

Seed note: The fruit capsules contain many minute seeds. Harvest the seeds when the capsules are dry but before they shatter.

Celosia

Name: Celosia spp. and cvs.

Size: 1 to 2 feet tall and wide

Days to germinate: 11 to 14

Germination conditions: Start seeds indoors six to eight weeks before the last frost. Do not cover seeds. Direct-sow after all danger of frost has passed.

Growing instructions: Plant in full sun and in fertile, well-drained soil. Space 8 to 12 inches apart.

Seed note: Do not collect or save seeds, because they are usually sterile.

Nasturtium

Name: Tropaeolum majus and cvs.

Size: 12 to 16 inches tall, spreading to 6 to 10 feet

Days to germinate: 7 to 14

Germination conditions: Start indoors six to eight weeks before the last frost, or direct-sow after the last frost. Cover seeds with 1 to 1½ inches of soil.

Growing instructions: Plant in full sun to partial shade and in light, well-drained soil; rich soil promotes foliage but few flowers. Space 8 to 12 inches apart.

Seed note: Harvest the seeds by removing the dried fruit that holds them; do not separate the seeds. Dry, store, and plant them intact.

California poppy

Name: Eschscholzia californica

Size: 12 to 18 inches tall and 6 to 12 inches wide

Days to germinate: 14 to 21

Germination conditions: Direct-sow on the soil surface in spring after all danger of frost has passed.

Growing instructions: Plant in full sun and in well-drained soil. It tolerates drought well.

Seed note: Allow the plant to self-sow, or collect the seedpods when they are light brown. Dry them in a warm location, then release the seeds from the pods and store.

Spider flower

Name: Cleome hassleriana cvs.

Size: 4 to 6 feet tall and 18 inches wide

Days to germinate: 10 to 14

Germination conditions: Stratify seeds at 40°F for two weeks prior to sowing. Start indoors six to eight weeks before the last frost, or direct-sow in spring or fall.

Growing instructions: Plant in full sun and in well-drained soil. Water regularly to establish.

Seed note: Snip the seedpods located along the stem before they shatter and self-sow. Remove the seeds from the pods and then dry them for a few weeks before storing.

Sunflower

Name: Helianthus annuus cvs.

Size: 4 to 10 feet tall and 18 to 24 inches wide

Days to germinate: 7 to 14

Germination conditions: Start indoors three to four weeks before the last frost, or direct-sow after all danger of frost has passed.

Growing instructions: Plant in full sun and in well-drained soil. Space 9 to 12 inches apart.

Seed note: Cut the expired blooms from the stalk, and hang them upside down to dry in a warm, well-ventilated location. Rub your hand over the seed head periodically when the seeds are ripe; they will fall off easily. Once they are removed from the flower, dry the seeds for another week and store.

Love-in-a-mist

Name: Nigella damascena and cvs.

Size: 12 to 18 inches tall and 1 foot wide

Days to germinate: 10 to 14

Germination conditions: Direct-sow in spring after all danger of frost has passed. Sow indoors, covered with ½ inch of soil, six to eight weeks before the last frost.

Growing instructions: Plant in full sun and in well-drained soil. Space 8 inches apart.

Seed note: To harvest the seed, allow the pods to dry on the plant and snip them off. Remove the seeds from the pod, dry out of the pod for a week, and store.

Ageratum

Name: Ageratum houstonianum cvs.

Size: 8 to 24 inches tall and wide

Days to germinate: 5 to 14

Germination conditions: Sow indoors six to eight weeks before the last frost. Cover seeds with 1/8 inch of soil, and place in a warm (80°F) location. Direct-sow in spring after all danger of frost has passed.

Growing instructions: Plant in full sun and in well-drained soil. Space 6 to 9 inches apart.

Seed note: Seeds are often sterile—do not save.