Trott: Fill your garden with flowering annuals

Flowering annual plants are the brightly colored dependable stars of our gardens.

From the common snapdragon (Antirrhinum majus), to beds of colorful zinnias (Zinnia elegans), your ornamental garden will be enhanced when you strategically use annuals. Their continuous blooms can fill voids in permanent plantings while young woody plants grow, and provide inexpensive color and cut flowers in almost any soil.

Annuals are used in perennial plant beds to continue interest following early blooming bulbs and perennials. They can be transplanted or direct-seeded into the spot where tulip and daffodil blooms have faded, or planted in front of woody flowering shrubs to provide further interest through the season.

Many fast-growing annuals will flower within seven weeks of sowing the seed, which can be planted directly into your garden bed.

Direct sowing requires a certain amount of planning and seedbed preparation. A well-made seedbed is necessary so that the seed will have enough air and moisture, and tiny roots will have a secure foothold.


Seedbed preparation includes:

  • Choose a sunny location for the garden.
  • Control any emerged weeds.
  • Water the soil, letting water settle until the soil is moist below the surface, but dry on top.
  • Rake the surface lightly until it is even and free of large soil clumps.
  • Thinly scatter seeds
  • Use the optimum spacing requirements listed on the back of seed packets.
  • Some species germinate faster if the seeds are given a special treatment, called scarification, prior to planting. This treatment breaks the hard seed coat and allows the seeds to absorb water more quickly, resulting in faster germination. Morning glories, for example, will germinate quickly and more uniformly if the seed coat is nicked slightly. This can be done using a nail clipper to snip off a small piece of the seed coat on one end. Scarify sweet pea seeds by filing the seed coat on one side. After scarifying the seeds, soak them in warm water for 24 hours before sowing.

If you’ve never direct seeded annual flowers, here are a few varieties you can try.

  • Bachelor's button (Centaurea cyanus): Germinates in 7-14 days, needs darkness to germinate
  • Spider flower (Cleome hasslerana): Germinates in 10-14 days
  • Cosmos (Cosmos bipinnatus and C. suphureus): Germinates in 5-10 days
  • Annual baby's breath (Gypsophilia elegans): Germinates in 10-15 days
  • Sunflower (Helianthus annuus): Germinates in 10-14 days
  • Morning glory (Ipomoea purpurea): Germinates in 5-7 days, scarify
  • Sweet pea (Lathryrus odoratus): Germinates in 10-14 days, scarify
  • Love-in-a-mist (Nigella damascena): Germinates in 10-15 days
  • Rose moss (Portulaca grandiflora): Germinates in 10-15 days
  • Marigold (Tagetes spp.): Germinates in 5-7 days
  • Nasturtium (Tropaeolum majus): Germinates in 7-12 days, scarify seeds; needs darkness to germinate
  • Zinnia (Zinnia elegans and Zinnia angustifolia): Germinates in 5-7 days

For more information about seed starting visit:
Until next time, happy gardening!

Robin Trott is a horticulture educator with University of Minnesota Extension. Contact her at 320-762-3890, or at trot0053@umn.

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