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How to Plant Flowers

As spring approaches, nurseries, and garden centers will be covered with flowers for sale. It’s the best way to brighten up your landscape and add pops of color to your garden.

Did you know starting flower seeds is simple and easy? Before you load up on potted plants, try your hand at growing your own flowers!

In this post, I’ll go over how to plant flowers by starting seeds indoors or direct sowing.

Let’s dive in!

Zinnia garden. Knowing how to plant flowers is one of the most enjoyable parts of gardening.

Why Plant Flowers

Why should you learn how to plant flowers? There are three main reasons that I believe starting flower seeds is important. You can improve your landscape appeal, benefit pollinators, and have access to cut flowers.

Landscape Appeal

Landscape appeal is maybe the most obvious reason for starting flower seeds. Flowers bloom in every color, so it’s the perfect way to add some brightness to your flower beds.

Layer in flowers with evergreen bushes and trees to round out your landscape.

Pollinator Benefits

Western Honey Bee

Give the bees and butterflies a helping hand. Growing flowering plants in your garden is extremely beneficial.

You’ll be providing pollen and nectar for pollinators. And in turn, they’ll help pollinate your vegetables for optimal fruit production.

Cut Flower Production

Isn’t it nice to have a bouquet of fresh-cut flowers on your dining room table? You can learn how to plant flowers specifically for cut flower production.

This will give you a large yield of stems to use for bouquets. Cut a bouquet every time you harvest vegetables to always have a beautiful centerpiece. Or, you can share an arrangement with your friends and family.


Best Flowers to Include in Your Garden

Let’s talk about the best flowers to include in your garden – both annual and perennial. I’ve included the easiest flowers to start from seed.

Pink and white bi-colored cosmos flowers.
Bi-colored cosmos.

Annuals

  • Zinnias – The easiest flower to direct sow – zinnias provide long, straight stems with blooms of every color. Butterflies love zinnias. And you can even find dwarf varieties that look great in a landscape bed.
  • Sunflowers – Sunflowers are extremely easy to direct sow. Plant them in your vegetable garden to help out pollinators. Did you know you can even use sunflowers as a support for beans?
  • Cosmos – Cosmos look lovely in a cut flower arrangement. The frilly, petite blooms will show out all summer. Pollinators love them, too.
  • Celosia – Celosia is a good cut flower to start indoors. The fluffy plumes add character and variety to an arrangement. You can also dry the plumes out to use in a winter arrangement.

Perennials

  • Coneflower – Coneflower, or echinacea, is a pollinator favorite. They’re native, drought-tolerant, and return every season. Add them to your landscape bed for a bright pop of color.
  • Yarrow – Yarrow is a flowering herb that grows long, sturdy stems. The flower heads are similar to dill or False Queen Anne’s Lace. Yarrow is hardy and easy to grow.
Purple coneflowers.
Purple coneflower.

When to Plant Flowers

Starting flower seeds is different for every type of flower. Most warm-season annuals, such as zinniassunflowers, and cosmos, can be direct sown after the last frost.

Flowers like celosia and yarrow do better if started indoors. Start these flowers indoors six to eight weeks before your last anticipated frost.

Coneflower, on the other hand, does better if direct sown in the fall. Direct sow the seeds eight weeks before your first anticipated frost.

If you experience harsh winters, coneflower can be started indoors six to eight weeks before the last frost in the spring.

To be sure, always follow specific directions for the flower you’re planting. This can often be found on the back of the seed packet or by a quick internet search.


How to Start Flowers Indoors

A small starter tray of sunflower seedlings.
Sunflower seedlings.

What You’ll Need

Successfully starting flower seeds requires a good seed starting setup.

Here are the main seed starting products I recommend:

Seedling Starting Equipment

Hoss Germination Mat

Indoor Seed Starting Light Kit

SunGrow Black Gold Seed Starting Mix

Potting Mix

48 Cell Seed Starting Kit

Small Containers

Gardening Gloves

Garden Shovel

Spray Bottle

Watering Can

Garden Labels

Check out Hoss Tools’ flower seed selection to stock up on all your favorite flowers. Hoss has great germination rates with their seeds. And they even include individual seed starting recommendations on the product page.

If you can’t find what you’re looking for at Hoss, True Leaf Market also has a wide selection of flower seeds.

Starting Flower Seeds

A starter tray of marigold seedlings.
Marigold seedlings.

Fill several seed starting trays with moistened seed starting mix. The mix should be flush with the top of the tray. Press down on the mix to remove any potential air pockets.

Once you’ve filled your trays, you’re ready to sow seeds. Using a sharpened pencil or the end of a label, make an indention in every cell.

The indention should match the recommended planting depth for that specific flower. You can usually find this information on the seed packet.

Place the seed in the hole and lightly cover it with the mix. Create a label for each tray to keep up with which flower variety you planted.

A small starter tray of zinnia seedlings.

Place the trays on a heat germination mat under a full spectrum grow light. The heat mat will speed up the germination time.

Transplanting Tips

Once the threat of frost has passed, you are ready to begin hardening off your flower seedlings.

Move your seed starting trays outside every day for a week. Start with one hour, then gradually increase their time outside every day.

This will get the seedlings used to outdoor temperatures, rain, and/or wind.

After this, the seedlings will be ready to transition to the garden.


How to Plant Flowers Outdoors

Newly sprouted seedlings in a garden.

Next, let’s look at how to plant flowers by direct sowing. I recommend this route for most warm-season annuals. Think zinnias, sunflowers, and cosmos.

Choose the Plant Site

Unless otherwise stated, flowers should be planted in a full-sun location. This means the site should receive six to eight hours of light per day.

The soil should be loose and well-draining. You can always loosen the soil beforehand with a rotary cultivator or bed rake.

To amend clay or sandy soil, work compost into the top six inches of the ground. This will increase drainage, improve soil pH, and introduce beneficial nutrients.

Direct Sow the Seeds

Following the seed packet’s directions, sow the seeds at the recommended depth and spacing. Lightly cover the seeds with soil after sowing.

If you’re planting multiple rows of flowers, always leave 12 to 36 inches between rows. This will give you enough room to come in and cut flowers.

It also helps with air flow between plants, which prevents mold and mildew.

Closeup of a nasturtium seedling in a garden.
A nasturtium seedling.

Thinning

It’s not a bad idea to sow more seeds than you’ll be able to keep. This will give you a sufficient amount of seedlings if some seeds don’t germinate.

Once the seedlings have developed two sets of leaves, thin the seedlings out to the recommended spacing. Always choose the strongest, healthiest seedlings to keep.

Pinching

Flowers, like zinnias and some celosia varieties, benefit from pinching.

Pinching encourages the plant to branch out and create more flower stems. It also prevents you from growing one giant flower stem that’s hard to work with.

Steps demonstrating how to pinch a snapdragon seedling.
Pinching a snapdragon seedling.

Once the flower has four sets of leaves, pinch just right above the fourth set of leaves. The plant should begin to branch out from that point.

Care and Maintenance

Many warm-season flowers do well in drought once established. But you should still aim to water flowers deeply at least once per week.

Always water at the soil level. Avoid getting water on the foliage to prevent diseases or burned foliage.

Flowers also love added nutrients. Apply a liquid fish fertilizer every few weeks to give your flowers a boost in production.


How to Harvest Flowers

An informal bouquet of cut flowers.

Now for the best part of starting flower seeds – harvesting!

If you’re growing flowers to cut for arrangements, you should wait until the flower reaches maturity to cut.

Most flowers have tell-tale signs that they are ready to be harvested. Always read up on how to tell if your flower is ready. This will prevent you from stunting further growth or cutting flimsy flowers.

Zinnias and yarrow, for example, will have sturdy stems. If you grab the stem and give it a slight shake, the bloom should remain steady. You can cut anytime after this.

Sunflowers should be harvested just as the bloom head begins to open. It will continue to open after being cut.

A sunflower about to bloom.

Always cut flower stems with a sharp knife or pruning shears.

Keep a bucket filled with cool water nearby. You can move flowers into the bucket as you harvest. Remove any foliage that will fall below the water line.


Wrapping Up How to Plant Flowers

Closeup of snapdragons in various colors.
Colorful snapdragons.

Learning how to plant flowers is beneficial for so many reasons. Whether you want to brighten your yard or have beautiful flowers to cut, starting flower seeds is worth it.

Did you know it’s beneficial to interplant flowers with vegetables? You can put your seed starting setup to use by starting vegetable seeds, as well. Visit the Seed Starting page on our website to learn how to start cool and warm-season vegetables!