What Month Should You Start Planting Flowers? (Best Spring Timing)

As the seed catalogs start rolling in and emails arrive describing the new varieties for the year, my hands itch to get my flower garden started. If it were up to me, I’d be planting out my summer flowers in February to get a jump on the season.

But I have to hold my horses and wait for a better, more appropriate month to start planting out my flower garden.

Flower gardeners typically start planting flowers in the spring month of May. This is when the weather has warmed enough that the risk of frost or freezing temperatures is quite low. There are many months of summer ahead for the flower plants to reach maturity and bloom for an extended period of time.

That’s what I remind myself of during the gloomy days of February. Does it help? Well, enough to make me wait a bit longer.

Why is May a great month to plant flowers?

Spring opens the gardening season with a sense of excitement, impatience, and a longing for fresh color. Although spring arrives in different areas of the US at different times, a safe bet for most garden zones is May.

This month is great for starting a flower garden for several reasons.

Flexible timing

• There’s flexibility to choose the beginning or the end of the month to accommodate your specific climate and weather patterns.
• There is plenty of time from May until the end of summer for you to harvest many, many bunches of cut flowers.
• If June rolls around and some plants aren’t thriving, or you’ve lost some plants to kids, dogs, and squirrels, you still have time to replant.

Wiggle room for direct sowing and transplanting

• If you were late getting your seeds started indoors back in March, you still have time to reseed.
• Direct sowing is a convenient option since spring rains will keep the soil moist (but don’t let your seeds wash away! Cover them with loose weave burlap if heavy rain is expected).
• Transplanted seedlings will also benefit from spring showers, helping them establish themselves in the garden beds.

Leaves time to set up garden systems

• You will have time to set up irrigation or find a good hand-watering schedule before the weather warms up too much.
• You can spread mulch while seedlings are small and before summer weeds get out of hand

A May planting of cut flower favorites like cosmos and zinnias will provide you with blooms just a couple of months later as the weather warms.

Which flowers should I plant in May?

By May, you can plant a whole range of warm-weather-loving cut flowers. These are the showy focal flowers like zinnias and sunflowers, as well as the greenery such as basil and amaranth. Choose a few varieties, and you’ll have a crop of summer cut flowers ready for picking.

Amaranth

This one is a great addition to the cutting garden for its versatility. Amaranth can be cut when the plant is still young to take advantage of its large leaves to fill out a bouquet and provide volume. Allow the plant to grow longer and it will develop large bracts of grain as spikes, plumes, or drooping fingers, depending on the variety.

Basil

Basil has two qualities going for it in the cutting garden. It makes excellent foliage in the vase, providing lush green leaves for an arrangement. Basil also brings a wonderful spicy scent, ranging from lemon to cinnamon to licorice depending on the variety. You’ll also get long spikes of purple or white flowers to add to your collection.

Celosia

Take your pick of feathery plumes or furled fans with celosia. Then decide if you want bright pinks, oranges, and reds or romantic peaches, creams, and light pinks to round out your celosia selection. From there, enjoy a summer full of blooms from these productive plants, and don’t forget to dry any leftover branches for dried arrangements and crafts.

Cosmos

Growing tall and feathery, cosmos produce virtual boatloads of blooms all summer if they get enough sun. From single, delicate pink blooms to white pom-pom looking flowers, cosmos are available in a range of shades and shapes.

Just like amaranth, cosmos also provide foliage for the cutting garden, as their feathery fern-like leaves are just as abundant as the blooms.

For more specific information on cosmos, check out this article, When To Plant Cosmos: The First And Last Planting Dates.

Gomphrena

Also known as globe amaranth, Gomphrena flowers are small ball-shaped blooms that have a long vase life of up to two weeks. You’re sure to find a favorite as the colors range from vibrant fuchsia and orange to soft lavenders and white.

Try drying Gomphrena as well, where they make sturdy and long-lasting souvenirs of summer.

Strawflower

Small blooms with spiky and squeaky petals make strawflowers a unique flower in the garden. They run the rainbow in color from red to yellow to white, and they dry beautifully for fall and winter arrangements. They also have a long vase life, so what’s not to love about strawflowers?

Sunflower

Hands down one of the iconic summer flowers, sunflowers will sprout quickly in soil warmed by the spring sun. If you choose single-stem varieties, be sure to plan for succession planting. This means planting a new crop every couple of weeks so you have a continuous harvest all summer.

Check out this article to learn more: What Sunflower Varieties Are Best For Cutting?

Zinnia

No garden is complete without summer zinnias. Available in colors ranging from bright and cheery reds, oranges, and pinks to antique shades of rose, rust, and cream, zinnias earn their place in the cutting garden. Reliable bloomers for weeks on end, zinnias make a long-lasting cut flower sure to brighten up any home.

Find out just how long you can plant zinnias in this article, Plant Another Round Of Zinnias (It’s Not Too Late).

What month is too late to start a flower garden?

If you’ve missed the prime spring window to plant flowers in your cutting garden, you still have a little wiggle room. There are a handful of flowers that you can plant as late as the end of July and still get some blooms during the summer months.

The risk of planting late is that you will run into your first fall frost sooner. This frost will kill off your tender summer cut flowers, though some hardy flowers will be able to pull through and continue blooming.

So the important thing to remember if it’s later in the growing season is to choose flowers that have a shorter time to maturity. This means they’ll bloom sooner rather than later. Most flowers bloom in a range of 50-120 days from planting.

Focus on the shorter end of that range if you’re getting flowers in the ground in June or July.

For much more information about late plantings and recommended varieties, jump over to this article, Too Late To Plant A Flowers Garden? A Guide To Summer Planting.