fast growing flower seeds

The Fastest Growing Flower Seeds

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If you are a new gardener or are working on a garden project with children, finding flower seeds that grow rapidly is important. The fastest-growing seeds germinate in a matter of days and flower in roughly two months. An important consideration for very young children is seed size, which should be big enough to pick up easily between thumb and finger, such as a nasturtium or sunflower seeds. In contrast, petunia seed is fine as dust.

Germination vs. Bloom Time

Some flower seeds, such as zinnias (Zinnia spp.), may germinate a few days after planting. Zinnias average from three to five days. However, that doesn’t mean they are among the fastest-growing flowers, because it can take zinnias 75 to 90 days to flower. Cosmos (Cosmos spp.) is another prime example. Although its seed germinates in seven to 10 days, cosmos doesn’t flower until 90 to 120 days after planting. In contrast, California poppy (Eschscholzia californica) may take about 21 days to germinate in U.S. Department of Agriculture plant hardiness zones 6 to 10, but flowers within 60. The fastest-growing flower seeds are those that germinate in 14 days or less and flower within 70 days. These include marigold (Tagetes spp.), nasturtium (Tropaeolum majus), annual phlox (Phlox drummondii) and sunflowers (Helianthus spp.). Aside from its genetic heritage, the speed of a flower’s growth depends on having its needs met. In the beginning, these conditions include seed planting depth and other germination concerns, such as light, temperature and moisture.

Impact of Seed Planting Depth

Planting a seed incorrectly can impede or end growth. Some seeds need light to germinate and must be sown on top of their growing medium, whether outdoors in the garden or indoors on seed flats. These include impatiens (Impatiens spp.) and petunias (Petunia spp.). For seeds that need darkness – such as those of calendula (Calendula spp.), phlox and sunflowers – a general rule is to plant at a depth twice the seed’s diameter. For example, large sunflower seeds require planting 1 1/2 to 2 1/2 inches deep. Marigolds, however, germinate whether planted under or on top of soil. Check seed packets for information about planting depth.

Other Needs for Quick Germination

Proper germination temperature and moisture also speed initial growth. Temperature requirements vary for the seeds of different plants. For example, the optimum daytime germination temperature for marigolds is 70 degrees Fahrenheit whereas snapdragons (Antirrhinum spp.) like it colder at 65 F. For most flower seeds, the daytime temperature needs to be somewhere between 60 to 80 F, and nighttime temperatures should be 10 to 15 degrees cooler. For indoor seed starting, if you feel comfortable with the temperature in your house, your seeds likely will too. Moisten the soil before planting, because watering immediately after sowing can cause seeds and soil to shift haphazardly. Keep the soil moist but not soggy during germination to avoid rot.

Seeding Location and Growth

Some plants do better if seeded outdoors. If seeded indoors, transplanting may slow their growth. These plants include cosmos, marigolds, nasturtium, sunflowers and zinnias. The rule for seeding outdoors is to wait until the threat of frost has passed. Flowers that do better when seeded indoors include impatiens and petunias. For seeds planted indoors, the growth time different flowers need before outdoor transplanting varies. Although impatiens may not be ready for transplanting until about eight weeks old, zinnias started indoors will become leggy and root-bound if kept inside that long. Consequently, if starting seeds indoors, you need to time germination based on a transplanting date when the danger of frost will have passed.

The Fastest Growing Flower Seeds. If you are a new gardener or are working on a garden project with children, finding flower seeds that grow rapidly is important. The fastest-growing seeds germinate in a matter of days and flower in roughly two months. An important consideration for very young children is seed size, …

10 Easy Annual Flowers to Start From Seeds

Whether you like to start your flower seeds indoors to get a head start on spring or sow them directly in the garden, many annual flowers have seeds with high germination rates and quick maturation rates to bring you armloads of summer blooms in your sunny or shady landscape. These annuals include giants for expansive gardens, petite flowers for container gardens, and vines for vertical drama.

Here are some of the easiest annuals to grow from seed.

Alyssum (Lobularia maritima)

Sweet alyssum seeds may germinate in as little as four days, maturing quickly to produce masses of tiny fragrant flowers for your spring garden. Start them indoors five or six weeks before​ the last frost, or outdoors after frost. You don’t need to cover the seeds, just sow them thickly and press them lightly into the soil with your finger. Use a spray bottle to keep the seedbed moist until the plants germinate.

Sweet alyssum grows 3 to 9 inches tall and makes for a good edging and bedding plant. If you shear the plants back after the first bloom, a second flush of flowers follows. The flowers often fade, though, in the heat of summer. Some gardeners remove them in the heat of summer, then replant when the weather cools in the fall.

  • USDA Growing Zones: 5 to 9; usually grown as annual
  • Color Varieties: White; pink, purple, and apricot cultivars also available
  • Sun Exposure: Full sun to part shade
  • Soil Needs: Medium moisture, well-drained soil

Celosia or Cockscomb (Celosia argenta, C. cristata)

This annual doesn’t enjoy the popularity of sunflowers or marigolds, but celosia’s unusual blooms that may resemble brain coral or feathers deserve a featured spot in every sunny garden. Although the seeds are tiny, they have a quick and high germination rate, and the plants may even self-sow in favorable areas. Start the seeds indoors six to eight weeks before the last frost. Sow three to four seeds per pot. Press the seed lightly into the soil to ensure contact and keep moist.

The celosias commonly planted as garden annuals are usually somewhat complicated hybrids of two or more species, but the cultivars are generally categorized into four groups:

Plumosa Group: Often called feather celosias or cock’s comb, this group has feathered, bright red flowers.

Cristata Group: Cultivars in this group have crested flowers with convoluted ridges that resemble brain corral. Flowers can be red, purple, or pink.

Childsii Group: This group, rarely sold at garden centers, has rounded flower heads that resemble twisted balls of yarn.

Spicata Group: Cultivars in this group cylindrical pink or rose flower heads with e a metallic sheen. ‘Flaming Series’ cultivars are members of this group.

  • USDA Growing Zones: 10 to 11; usually planted as an annual
  • Color Varieties: Bright red, pink, purple
  • Sun Exposure: Bright red, pink, purple
  • Soil Needs: Rich, moist, well-drained soil

Cosmos (Cosmos sulphureus, C. bipinnatus)

Cosmos flowers are as tough as nails from the day they germinate until fall’s first frost. Plant them once, and then watch each year for the ferny foliage that will let you know the self-seeded plants have volunteered in your garden again. Sow them directly in the sunny garden anytime in the spring; the plants know when to germinate, so these flowers are truly a no-brainer for beginners.

There are two forms of annual cosmos: C. sulpherous is an upright daisy-like flower that grows 1 to 3 feet tall, with yellow-orange flowers. C. bipinnatus has delicate threadlike foliage and daisy-like flowers of pink, red, or white. It can grow to 4 feet. Both plants are natives to Mexico.

  • USDA Growing Zones: True annual; grown in all zones
  • Color Varieties: Yellow (C. sulphureus); red, pink, white (C. bipinnatus)
  • Sun Exposure: Full sun
  • Soil Needs: Dry to medium moisture, well-drained soil

Hyacinth Bean (Lablab purpureus)

Hyacinth bean is a beautiful flowering vine that’s easier to grow than a weed. This plant will cover your chain link fence or pergola for the summer, without self-seeding everywhere or becoming a nuisance. Push the plump seeds just under the soil’s surface when day temperatures average 75 degrees Fahrenheit and keep them evenly moist until germination occurs, about 10 days later. The vines will be a source of interesting pods and flowers for the vase by late summer.

The seeds inside the bean pods can be collected in the fall for spring planting, but be aware that they are toxic unless thoroughly cooked.

  • USDA Growing Zones: 10 to 11; usually grown as an annual
  • Color Varieties: Rose purple, white, pink
  • Sun Exposure: Full sun to part shade
  • Soil Needs: Medium moisture, well-drained soil

Impatiens (Impatiens walleriana)

Although impatiens seeds are tiny, avoid buying the pelletized version of the seeds covered with a substance that makes them easier to handle. This coating slows down germination considerably. Impatiens need light, warmth, and moisture to germinate. Sow seeds directly on top of the soil indoors about two months before the last frost. The well-branched plants will light up your shade garden all summer. Planting directly in the garden is less practical, since the plants take quite a long time to mature into flowers—about 3 months.

For some time, impatiens vanished from garden centers because of downy mildew, a devastating fungal disease that killed virtually all seed stock plants. Recently, however, several disease-resistant cultivars have been developed, so you can once again use this plant freely in your shady garden beds.

  • USDA Growing Zones: 10 to 11; usually grown as an annual
  • Color Varieties: Pink, red, purple, salmon, orange, white, bicolors
  • Sun Exposure: Part shade to full shade
  • Soil Needs: Rich, moist, well-drained soil

Marigold (Tagetes spp.)

Most of the familiar garden varieties of marigolds fall into one of three species:

African marigolds (Tagetes erecta): These have large pompom flowers. The plants can grow to 4 feet, and the flowers can be as much as 5 inches across. Colors are various shades of yellow and orange.

French marigolds (Tagetes patula): French marigolds have the longest bloom periods, and the plants tend to be short and bushy. They have purple-tinged stems with double flower heads in yellow, orange, and mahogany, about 2 inches across.

Signet marigolds (Tagetes tenuifolia): These look much different than other bedding marigolds, with lacy leaves and small, single, daisy-like flowers. They come in yellow and orange.

If you’ve had trouble growing marigolds from seed in the past, try growing some of the French varieties, which are more disease-resistant than the American types. ‘Queen Sophia’ is an All-America winner to try. Seeds germinate in less than a week in warm, moist soil. It takes about 8 weeks for plants to bloom from seeds, so you may want to start them indoors.

  • USDA Growing Zones: True annual; used in all zones
  • Color Varieties: Yellow, orange, white
  • Sun Exposure: Full sun
  • Soil Needs: Dry to medium moisture, well-drained soil; prefers rather barren soil

Morning Glory (Ipomoea purpurea)

Don’t be intimidated by the hard seed coats of morning glories. Just soak them overnight in warm water, and plant the swollen seeds under a quarter-inch of soil indoors two weeks before your last frost. Make sure the transplants have something to cling to when you set them out. Are you a night owl and not a morning person? Just swap morning glories for moonflower seeds and get the same results.

Morning glories grow quickly when planted directly in the garden, but for a headstart on blooms, you can start them indoors six to eight weeks before the last frost date.

  • USDA Growing Zones: True annual; grown in all zones
  • Color Varieties: Purple or blue with white throats; cultivars in white, pink, red, magenta also available
  • Sun Exposure: Full sun
  • Soil Needs: Moist, well-drained soil

Common Nasturtium (Tropaeolum majus)

What’s not to like about nasturtiums? They’re edible, they scramble over eyesores in the landscape, they have interesting foliage and brilliant flowers, and they thrive on neglect. The size of peas, nasturtium seeds are easy to handle and plant. But they don’t like transplanting much, so stick them in moist soil in a sunny spot as soon as the danger of frost is past. Or, start them indoors about four weeks prior to the last frost.

Nasturtiums are a complicated group featuring many cultivars derived from hybrids of different Tropaeolum species. There are both low mounding types and vining varieties within this group, so carefully research the types of seeds you buy to make sure you get what you want.

  • USDA Growing Zones: 9 to 11; usually grown as annuals
  • Color Varieties: Red, orange, yellow, creamy white
  • Sun Exposure: Full sun to part shade
  • Soil Needs: Poor to average soil that is slightly acidic

Sunflower (Helianthus annuus)

There’s a reason these flower seeds are included in every pre-packaged children’s garden kit you’ve ever seen. Sunflower seeds are raring to go as soon as a child’s pudgy finger pushes them into warm, moist soil. These seeds are best started directly in the ground outdoors, as the seedlings get large and gangly fast in a little jiffy peat pot. If you must start them indoors, give them a strong light source to keep them stocky.

Different sunflower varieties have different growth habits, from about 3 feet to as much as 10 feet—make sure to buy the variety appropriate for your needs. Leave the flower heads in place after they fade to provide food for birds.

  • USDA Growing Zones: True annual; grown in all zones
  • Color Varieties: Yellow, orange, red, mahogany, bicolors
  • Sun Exposure: Full sun
  • Soil Needs: Dry to average moisture, well-drained soil

Zinnias (Zinnia spp.)

If you like the look of dahlias but don’t want the fuss, grow zinnias. This is the way to go if you want an entire cutting garden of ruffled blooms from one packet of seeds. Zinnias are eager to germinate and perform in your summer garden, but the trick in getting them to grow is to give them warm conditions. They will wither away from damping-off fungus in your cold spring soil. Plant them outside about the time you set your tomatoes out when evening temperatures average 60 degrees Fahrenheit. You can start them indoors a month before​ the last frost if you desire earlier blooms.

The many cultivars of zinnia are derived from one of several species:

Zinnia elegans (common zinnia): Plants 1 to 4 feet tall on hairy branching stems produce flowers ranging from daisy-like single blooms to dense pompoms (depending on variety).

Zinnea angustifolia (creeping zinnia): With many low-growing varieties, creeping zinnias also have narrower leaves than the common zinnia.

Zinnia grandiflora (Rocky Mountain or prairie zinnia): This group includes small narrow-leaved plants about 6 inches tall with yellow-orange flowers.

Zinnea haageana (Haage’s zinnia or Mexican zinnia): These are narrow-leaved plants up to 2 feet tall with 1-inch flower heads containing yellow rays and orange center disks.

  • USDA Growing Zones: True annual; grown in all zones
  • Color Varieties: Red, yellow, orange, pink, rose, lavender, purple, green, white
  • Sun Exposure: Full sun
  • Soil Needs: Moist, well-drained soil

Annual flowers such as marigolds and zinnias offer an easy way to create an inexpensive, quick garden. These 10 plants are easy to grow in any climate.