How to Start a Flower Garden from Seeds

The first step toward a successful flower garden is choosing the right flower seeds for your garden site and climate. Some flowers tolerate drought better than others. If you live in a dry climate, choose flowers that prefer little watering. If you live in a wet climate, choose flowers that
prefer more water. To learn more about your climate, refer to the USDA Hardiness
Zone chart above (updated October 2023) or check out the back of most flower seed packs.

Once you know what will work best in your climate, determine how much sun your garden bed will get. This will help decide if you need flower seeds that do best in either sun or shade.

Tip: Extend your bloom season by strategically choosing flowers that suit your USDA Plant Hardiness Zone. This works especially well with perennial flowers.

Having blooming plants all season long is a matter of timing. A good rule of thumb is to sow annual flower seeds as early after the last spring frost as possible. For early-spring perennial blooms, plant these types of flower seeds in late summer to early fall so that they can germinate over winter. For both annual and perennial seed sowing, use the maturity dates on your seed packets to plan for specific flowers.

Tip: Some perennial flower seeds can take longer to germinate. If you want them to bloom earlier in the season, starting their seeds indoors is the best method.

Plants vary on how much or how little sunlight they need to grow and bloom. It’s essential for you to understand how much sun your garden gets and how long. For example, when a seed packet says the plant requires partial shade that means it needs at least two to four hours of sun a day. Or if it says the plant needs partial sun, that means it requires at least four to six hours of full sun a day.

Choose a planting location that gets the right amount of sunlight for the seeds you’ve chosen. Take time to observe how the sun works in your garden and in different parts of your garden. Note which parts of your garden site are in the sun, when they are in the sun and for how long. Likewise, keep a record of which sections are shady and for how long. Use this information to position your flowers in the optimum garden spot.

Tip: Make sure to keep a record of how light in your garden varies season after season.

Before you choose seeds, think about if you want annual flowers, perennial flowers or a combination in your garden.

• Annual flowers will bloom until
the
first
frost.
While they attract many pollinators that are great for your other garden plants, they must be replanted each year if you want to continue to enjoy them.
Popular annual flowers are
zinnias, geraniums, impatiens, pansies and petunias.
• Perennial flowers go dormant when it’s cold and pop back up in the spring. Their seeds may take longer to germinate than annual flower seeds.
Plus, keep in mind that some perennial flowers that thrive in warmer climates cannot survive a harsh winter. Treat them as annuals. Popular perennial flowers include phlox, coneflowers and daisies.

You can start flower seeds directly in your garden bed through a method called “direct sowing.” When direct-sowing, you can expect blooms by mid-summer. This method works well with hardy, annual flower seeds such as sunflowers, marigolds, bachelor buttons, cosmos and morning glories.

• Prepare the soil in your garden bed. Break up dense soil and mix in gardening soil or compost to lighten it.
• Water the soil until it is moist throughout.
• Read each seed packet to determine how far apart and how deep to plant different flower seeds.
• If you plan to thin the seedlings later, sow seeds densely.
• Keep soil moist. Seeds need consistent moisture to germinate.
• Water gently to avoid washing away the soil or seeds. Water less often as seedlings sprout.
• Fertilize and thin the seedlings as needed.

When you start seeds indoors, you don’t have to worry about unexpected frosts. You can start sowing in early spring and replant your flowers outdoors at the first sign of warm weather. When you start flower seeds indoors, you can get blooms by the end of spring or early summer.

• Prepare a seed tray with potting soil or use a seed starter.
• Place the potting soil in a bowl and water it until it is moist but not dripping wet.
• Fill each cell in the seed tray with the moist soil. Tamp the tray against the table to eliminate any air pockets.
• Poke a hole into the soil in each cell using either your finger or a pencil.
• Read the flower seed packet to see how deep the seeds should be planted. A good rule of thumb is to plant a seed at a depth twice its size.
• Place one or two seeds in each hole and cover lightly with more potting soil.
• Place the seed tray in a plastic tub or drip tray with about an inch of water at the bottom.
Allow the soil to absorb water from the bottom and refresh the water as needed.
• Wait until the seeds have sprouted into seedlings before watering from the top.
• Cover the tray with a clear plastic top or plastic wrap to insulate the seeds.
• Place the tray on top of a heat mat or in a warm corner that’s at least 65-degrees Fahrenheit.
• Once seedlings have sprouted, remove the plastic covering and tray of water. Begin watering overhead with a spray bottle whenever the soil appears dry.

Transition mature seedlings outdoors when the weather is warm enough. Set the seedlings outside each day for increasingly longer periods of time. This will acclimate them to natural temperature changes. When all risk of frost has passed, you can plant the seedlings in your garden beds.

If you want to plant flower seeds early in the season, use a cold frame. A cold frame is a garden bed that is insulated with a tight-fitting, transparent lid. It traps heat from the sun to keep seeds and young plants warm in cold weather. You can even use a cold frame to overwinter perennial flower seeds.

• Prepare the cold frame at least two weeks before sowing seeds.
• Direct sow flower seeds in the cold frame.
• Once the seeds have germinated into seedlings, vent the cold frame during the day when the outdoor temperature reaches 45 to 50-degrees Fahrenheit.
• Most plants die in cold frames due to overheating and drought. Pay close attention to the soil water levels and plan a ventilation schedule.

Starting flowers from seeds is a great way to get kids interested in gardening. Allow them to choose their favorite variety of flowers and get them involved in the early care of the seedlings. Watching seeds grow in seed trays can be a great learning opportunity for kids. Plus, replanting the seedlings in the garden
can get the whole family outdoors to enjoy the spring weather.