10 Flowers to Plant in March: Best Early Spring Blooms for a Colorful Garden Awakening

March is one of my favorite months in the garden. As winter begins to loosen its grip and the first signs of spring emerge, I find myself eagerly reaching for seed packets and planning my flower beds.

The soil is warming up, daylight hours are increasing, and there’s a palpable sense of anticipation in the air that only gardeners truly understand.

Planting flowers in March gives your garden a head start and rewards you with earlier blooms and a longer growing season. I’ve learned this through years of trial and error in my own backyard. Some of my most successful flower displays have come from seeds and plants I’ve started in this transitional month.

Whether you’re a seasoned gardener or just beginning your plant journey, March offers the perfect opportunity to get your hands dirty and lay the groundwork for a season of colorful blooms.

1) Sunflowers

I’ve always had a soft spot for sunflowers. There’s something magical about watching those cheerful giants turn their faces to follow the sun throughout the day. It’s like they’re eager students, not wanting to miss a single ray of sunshine!

March is actually the perfect time to start sowing sunflower seeds indoors in many regions. I like to plant them an inch deep in individual pots filled with seed compost. They germinate quickly when placed somewhere warm and bright.

These sunny beauties aren’t just pretty faces – they’re sun worshippers that need 6 to 8 hours of direct sunlight daily to reach their full potential. I’ve learned this the hard way after planting some in a partially shaded spot one year. They grew, but looked rather sad and stunted.

In warmer southern regions like Florida, sunflowers can be seeded directly outdoors in late winter to early spring. They’ll reward you with gorgeous blooms by mid-spring! Just be aware they don’t love intense summer heat.

I’ve discovered sunflowers make excellent companions for other plants too. They’re like aphid magnets, drawing these pests away from your other garden treasures. Ants actually herd aphids onto sunflowers like tiny livestock – nature is fascinating!

2) Zinnias

I’ve got a confession: zinnias are my secret weapon flowers! These colorful beauties have saved many of my garden designs with their reliable blooms and vibrant colors.

Zinnias are one of the easiest cut flowers you can grow, making them perfect if you’re just getting started with gardening. They grow VERY quickly and don’t need much babying.

Now about timing – this is important! Even though it’s March, I’ve learned the hard way not to start zinnias too early. They really don’t like being indoors for long. Instead, I recommend waiting as late into spring as you can stand it.

If you absolutely must start them in March, don’t go earlier than 6 weeks before your last frost date. I once jumped the gun and had leggy, sad zinnias that never recovered properly.

These summer superstars will bloom from summer until the first hard frost of fall. I plant mine in batches every few weeks to ensure I have continuous color throughout the season.

3) Snapdragons

I’ve always had a soft spot for snapdragons. These charming flowers with their dragon-mouth blooms bring such joy to spring gardens! They’re one of my favorite flowers to plant in March, especially since they thrive in cooler weather.

Snapdragons are wonderfully cold-hardy plants, making them perfect for early spring planting. I typically get mine in the ground around mid-March, though I do cover them on particularly chilly nights. These resilient beauties reward my care with months of colorful blooms.

What I love most about snapdragons is their long-lasting flower show. They start blooming in early spring and continue throughout the season. I’ve found that giving them a sunny spot works best, though they’ll still flower in partial shade – just not quite as abundantly.

The soil needs to drain well for snapdragons to thrive. My first attempt at growing them in my clay-heavy garden was disappointing until I amended the soil. Now they pop up reliably each year.

Don’t worry if your transplants look tiny at first – these little seedlings grow quickly once established. I’ve watched mine transform from fragile-looking sprouts to sturdy flowering plants in just a few weeks.

4) Nasturtiums

I’ve had a love affair with nasturtiums for years now. These vibrant flowers are among the easiest and most rewarding plants you can sow in March. Their round leaves and bright blooms in oranges, reds, and yellows bring so much joy to my garden!

If you’re eager to get planting, you can start nasturtium seeds indoors 2-4 weeks before your last spring frost. I like to give them a head start this way, especially since we’re approaching late March 2025 already.

For direct outdoor sowing, wait until the soil has warmed up. I’ve found they germinate quickly once the chill has left the ground. Just pop the seeds about an inch deep in the soil, and watch the magic happen!

These flowers aren’t just pretty faces – they’re edible too! I toss the peppery flowers and leaves into salads for a spicy kick. My garden guests are always impressed when I casually mention they can eat the garnish.

Nasturtiums need full sun to thrive – aim for a spot with at least 6-8 hours of direct sunlight. I’ve discovered they actually bloom better in poor soil. When I pampered them with rich compost, I got tons of leaves but fewer flowers!

Be prepared – these plants can get quite vigorous. Last year, my nasturtiums practically took over my garden bed. I wasn’t upset though – more flowers for my kitchen experiments!

5) Marigolds

I’ve always had a soft spot for marigolds in my spring garden planning. These cheerful little flowers with their bold orange and yellow blooms are some of the easiest annuals to grow, even for beginners.

Now, timing is everything with marigolds. While they’re wonderful spring flowers, they’re actually quite sensitive to cold. I’ve learned the hard way that marigolds won’t germinate until soil temperatures reach at least 65°F, and ideally 70°F.

For March planting in most regions, I recommend starting marigold seeds indoors. This gives them a head start while we wait for the soil to warm up properly. I usually sow mine in small pots about 4-6 weeks before our last frost date.

What I love most about marigolds is how they thrive in full sunshine and can handle blazing hot summers when other flowers wilt. The African and signet varieties are particularly drought-tolerant, which is perfect for my forgetful watering habits!

My favorite budget-friendly tip? You can save dried flowers at season’s end and simply scatter them in your garden next spring. I’ve gotten hundreds of volunteer marigolds this way without spending an extra penny!

Marigolds aren’t just pretty—they’re practical too. I plant them around my vegetable garden because their strong scent helps deter certain pests. They’re like tiny, colorful garden guardians!

6) Cosmos

I’ve always had a soft spot for cosmos flowers – they’re like the friendly neighbors of the garden world! These colorful, daisy-like blooms are some of the easiest flowers you can grow from seed in March.

I start my cosmos seeds indoors about 4-6 weeks before our last frost date. They don’t ask for much – just a little pot, some seed starting mix, and a sunny windowsill. I’ve found they germinate quickly and grow enthusiastically, almost as if they’re eager to show off.

Once all danger of frost has passed (usually late May in my garden), I plant the seedlings out. They truly thrive in full sun and average garden soil. The less fuss you make over them, the happier they seem!

One thing I’ve learned about cosmos is patience. They might take their sweet time to bloom, but trust me, it’s worth the wait. A gardener on Reddit mentioned that in zone 7a, cosmos flowers appear toward the end of the season, and I’ve found the same in my garden.

My favorite thing about cosmos has to be their carefree dancing in summer breezes. They attract butterflies, bees, and compliments from neighbors in equal measure!

7) Lobelia

I’ve always been charmed by Lobelia’s delicate beauty. These small but mighty flowers create stunning cascades of color that can transform any garden or container. Their tiny star-shaped blooms in shades of white, lilac, and that signature electric blue never fail to catch my eye.

Lobelia is perfect for March planting because it thrives in cooler weather. I’ve found they’re happiest when given morning sunshine with a bit of afternoon shade. My patio pots from last spring were absolute showstoppers when I positioned them just right!

When I plant Lobelia, I always make sure to use rich, well-draining soil. They’re not fans of soggy feet, but they do appreciate consistent moisture. I’ve learned through trial and error that they prefer soil with plenty of organic matter mixed in.

Temperature is key with these beauties. I’ve noticed they perform best when evening temperatures stay between 50-70°F. When summer heat arrives, my Lobelias often take a little break from flowering, only to perk up again when cooler fall temperatures return.

I love using Lobelia in hanging baskets where their trailing habit can really shine. They also make fantastic partners for other spring flowers in container arrangements, creating that coveted “thriller, filler, spiller” effect.

8) Calendula

I’ve always had a soft spot for calendula in my spring garden. These cheerful, daisy-like flowers bring such wonderful splashes of orange and yellow just when the garden needs some color!

Calendula is super easy to grow from seed, which is why I like to sow them directly in March. I simply plant the seeds about ½ inch deep and space them 10 inches apart. The little seedlings pop up quickly – usually in just 5-10 days!

One thing I love about calendula is how adaptable it is. It can handle full sun or part shade, though I’ve found it prefers cooler temperatures. When summer heat arrives, my calendulas start to slow down.

March planting gives calendula plenty of time to establish before summer. This timing lets me enjoy cheerful flowers from late spring until the heat takes over.

In my vegetable garden, I’ve discovered calendula makes a fantastic companion plant. I like to tuck it in near my lettuce and kale beds where it serves as a trap crop for certain pests.

The flowers aren’t just pretty – they’re useful too! I dry some for teas and skin salves. That dual-purpose nature is why calendula has earned a permanent spot in my March planting routine.

9) Dahlias

I used to think dahlias were only for expert gardeners, but they’re actually quite friendly once you understand their timing! Dahlias are summer-blooming beauties that don’t like the cold one bit.

March is a perfect time to start thinking about your dahlia plans. If you’re in a warmer climate, you might be able to plant your dahlias outside after your last frost date has passed. For most of us though, it’s still too risky.

I prefer starting my dahlias indoors in March. I plant the tubers in pots with good drainage and keep them in a warm spot until the danger of frost is gone. This gives them a head start on the growing season!

If you’re in Seattle or similar cooler climates, be cautious. As one grower wisely noted, “Starting in March, it’s always a gamble because we could still get a hard freeze”.

Many professional growers start their dahlias in early March inside, then move them to greenhouses before planting in the field. I’ve tried this method with great success in my own garden!

10) Pansies

I can’t help but smile when I see those adorable “faces” of pansies brightening up my early spring garden. These hardy little flowers are perfect for March planting because they actually thrive in cool weather. While other plants are still sleeping, pansies are ready to party!

In my Zone 6 garden, I’ve found that pansies can handle those unexpected late frosts that sometimes sneak up on us in March. They’re surprisingly tough despite their delicate appearance. I’ve even seen my pansies poking through a light snow, still looking perky and colorful!

When I plant pansies, I make sure to give them a spot with good morning sun. They appreciate the gentle morning rays but can get a bit wilted if they bake in hot afternoon sun. I’ve learned this the hard way after cooking a few batches in previous years.

Pansies are considered cool-weather favorites and work beautifully in both containers and borders. I love tucking them around spring bulbs to create a layered look in my garden beds. The color combinations are endless – purples, yellows, whites, and those stunning bicolors that look like they’ve been painted by hand.

If you deadhead them regularly (I just pinch off the spent blooms), they’ll keep flowering right through the cool spring weather. Once summer heat arrives, they’ll slow down, but I’ve had some varieties return with vigor in fall when temperatures drop again.

Understanding the March Climate

March is a thrilling but tricky month for us gardeners! The weather swings wildly between winter’s final grip and spring’s first warm embrace. I’ve learned through many years of muddy boots and chilly fingers that understanding these patterns helps me plant the right flowers at the right time.

Regional Variations

Where you live makes all the difference in March gardening! In my Zone 6 garden, March is perfect for planting roses, trees, and shrubs when mild weather arrives. But my friend in Zone 3 is still shoveling snow!

Southern gardeners can dive right in with tender annuals, while northern folks like me need to focus on cold-hardy options like pansies and snapdragons. These cool-season flowers bring early color while tolerating those inevitable late frosts.

I’ve found soil temperature matters more than air temperature. My gardening journal shows that when soil stays below 50°F, many seeds just sit there sulking. A simple soil thermometer has saved me countless failed plantings!

Influence of Daylight on Growth

Have you noticed how plants seem to wake up as March progresses? It’s not just the warming temperatures – it’s the increasing daylight that makes the magic happen!

In my experience, March’s lengthening days trigger hormonal changes in plants that stimulate growth. I’ve watched my dormant perennials suddenly sprout when we cross that 12-hour daylight threshold, even when temperatures haven’t changed much.

For indoor seed starting (my favorite March activity!), I’ve learned to mimic this natural light increase. My seedlings grow stronger with 14-16 hours of grow light daily, preventing that leggy, stretched-out look.

Different plants respond differently to day length. My snapdragons flourish in March’s increasing light, while some summer bloomers need even longer days to trigger flowering. I keep a small chart above my potting bench to remember each plant’s preferences.

Preparing Your Garden for March Planting

March is my absolute favorite time in the garden! The soil is waking up, and so are my planting ambitions. Before those spring flowers go into the ground, I need to make sure my garden beds are ready to support all that gorgeous growth.

Soil Preparation Essentials

I’ve learned the hard way that trying to plant in unprepared soil is like trying to bake a cake with cold butter – it just doesn’t work well! First, I clear away any winter debris like fallen branches, dead leaves, and those pesky weeds that somehow survived the cold.

Once that’s done, I grab my trusty garden fork and gently turn the soil to about 6-8 inches deep. This helps work the beds properly and improves drainage. I’m always careful not to dig when the soil is too wet – it creates clumps that are harder to break up later!

Next, I add a good 2-3 inches of compost to the top. My homemade compost is my garden’s best friend, but store-bought works great too. This dark, crumbly goodness improves soil structure and adds nutrients my flowers will love.

For clay soils (my constant gardening nemesis!), I mix in some sand and extra organic matter to improve drainage. For sandy soils, extra compost helps retain moisture better.

Choosing the Right Fertilizer

Fertilizer choices used to overwhelm me until I learned to think about what my plants actually need.

For spring flowers, I prefer a balanced fertilizer with equal parts nitrogen, phosphorus, and potassium. Look for numbers like 10-10-10 on the package.

My favorite options are organic. They release nutrients slowly and build soil health over time.

My go-to choices include:

• Bone meal: Amazing for bulbs and perennials (high in phosphorus for root growth)
• Compost tea: I brew this myself for a gentle boost
• Fish emulsion: Smells terrible but works wonders!
• Worm castings: Gentle enough for even delicate seedlings

I always apply fertilizer before planting, gently working it into the top few inches of soil. This puts nutrients right where new roots can find them.

Remember to water thoroughly after applying. This helps activate the fertilizer and starts the nutrient release process.

The best advice I ever received? Test your soil first! Those inexpensive home test kits have saved me from over-fertilizing so many times.