Spring is the perfect time to start planting flower seeds outdoors for a gorgeous garden. With the right preparation and timing you can have stunning blooms all season long. In this article we’ll go over when and how to plant flower seeds in spring.
When to Plant Flower Seeds in Spring
The timing of planting flower seeds depends on your USDA Hardiness Zone and last spring frost date. Most flower seeds should be sown after the last frost so the young seedlings aren’t damaged by the cold.
Check your local frost dates and use the table below as a guide for when to plant flower seeds
- Zones 3-4: Mid to late May
- Zones 5-6: Early to mid May
- Zones 7-8: Late April to early May
- Zones 9-10: Mid to late April
Some flower varieties can handle cooler soil temperatures and can be planted 1-2 weeks before your last frost date. These include calendulas, pansies, snapdragons, and violas.
Don’t be tempted to start too early. Seeds sown while the soil is still cold and wet will be prone to rotting.
How to Prepare the Soil
Proper soil preparation is key for healthy seedlings. Follow these tips:
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Remove any weeds sticks and rocks from the area.
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Loosen the top 6 inches of soil with a hoe, rake or tiller. Break up large clumps.
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Mix in 2-4 inches of compost or other organic matter like peat moss. This improves drainage and provides nutrients.
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Rake the area smooth and create planting rows.
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Consider adding a thin layer of seed starting mix on top of the soil to give seeds the ideal germination environment.
Direct Sowing vs Starting Indoors
You have two options for planting flower seeds – direct sowing right into the garden soil or starting indoors and transplanting. Here are the pros and cons of each:
Direct Sowing
Pros:
- Easier, less work
- No risk of transplant shock
- Seeds germinate in ideal outdoor conditions
Cons:
- More exposure to pests like slugs
- Need to thin crowded seedlings
- Slower germination in cool soil
Starting Indoors
Pros:
- Earlier bloom time
- More control over growing conditions
- Less wasting seeds
- Healthier, stockier transplants
Cons:
- More effort and supplies needed
- Risk of transplant shock
- Leggy, weak plants if not hardened off properly
In general, it’s best to direct sow hardy annuals like zinnias, sunflowers and cosmos. Start tender annuals like petunias, marigolds and impatiens indoors.
How to Direct Sow Seeds
Follow these steps for sowing flower seeds directly in the garden:
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Refer to your seed packet for proper planting depth. As a rule of thumb, plant 2-3 times as deep as the width of the seed. Small seeds only need 1/4 inches depth.
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Poke holes in the soil with your finger, a pencil or seeding tool. Space holes according to the mature plant’s spread.
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Place 2-3 seeds in each hole and gently cover with soil.
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Label rows with seed type and date planted.
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Water gently with a watering can to avoid displacing seeds.
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Cover beds with floating row covers to retain moisture and prevent pests.
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Once seedlings emerge, thin them to the recommended spacing on the seed packet.
How to Start Seeds Indoors
Here are some tips for successfully starting flower seeds indoors:
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Choose containers with drainage holes like trays, pots or peat pellets.
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Use a seed starting mix, not garden soil. It’s lightweight and resists disease.
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Follow seed packet instructions for planting depth and spacing seeds.
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Cover containers with plastic wrap or dome lids to retain moisture.
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Place containers on a heat mat or near a sunny window. Ideal temp is 70-75°F.
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Once sprouted, move to full sunlight and remove domes.
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Water when top of soil feels dry to the touch. Don’t oversaturate.
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Thin seedlings and transplant into larger containers as needed.
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Harden off plants for 7-10 days before transplanting outdoors.
Ongoing Flower Seed Care
Whether you sow seeds directly or start indoors, your young plants need care to thrive:
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Water seed beds frequently, keeping top 2 inches moist. Avoid excess moisture.
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Pull weeds and amend soil with compost tea or organic fertilizer.
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Install supports like trellises and cages once plants are 6 inches tall.
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Cover beds with horticulture fleece or cloches if cold weather returns.
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Pinch back gangly plants to encourage bushier growth. Deadhead spent blooms for more flowering.
With the right plan and preparation, planting flower seeds in spring will lead to a fabulous garden. Pay attention to timing, soil condition, and seedling care for best results. Soon you’ll have vibrant flowers to enjoy all season long.
Planting flower seeds at the proper time and following good growing practices is the formula for a successful spring garden. Determine your last frost date, prepare the soil, and start seeds at the right time for your climate. Give your seedlings attentive care. In a few weeks, you’ll reap the rewards of all your efforts with a landscape full of blossoms.
10 of My Favorite Annual Flower Seeds
The flowers are blue, pink, white, or purple and very slightly scented. The blue is especially desirable because there are only a few really blue summer flowers. Cornflowers also go by the name of bachelor’s buttons because men used to put them into the buttonhole of their jackets.
Keep deadheading to get as many blooms as possible. These plants will stop flowering when the weather gets hot and humid.
The colors are vibrant reds, oranges, yellows, and pinks. Foliage can be green or crimson. Find out more about celebrating Celosia here.
Sow the seeds inside 4-6 weeks before your last frost or outside after the last frost.
There are many possible types from the traditional pink and white to the oranges and yellows of the sulfur cosmos. Choose them by flower color and plant height.
If you garden in a cool summer area, check how many days this flower takes from seed to bloom and start them inside, if necessary. In any climate, they do their best flowering later in the summer.
The flowers are tall and come in the loveliest of blues, some soft pinky-purples, and white. Each stem has many little flowers. They make a really good cut flower.
They do well in late spring and early summer, in hot climates, and will last well into summer in cool climates.
If you want them for edging a border, go for the short ones; whereas, for cutting, pick ones that have nice long stems. The narrow slender seeds are easy to sow directly into the garden and have often been sown alongside vegetables.
Wait until the soil warms up before planting, and make a couple of sowings a few weeks apart for continued bloom. They can be sown inside, up to six weeks before the last frost.
The seeds are round and can be sown in places where the rounded leaves come up first. They may flower a little in late spring and will do really well in cool summers. In hot summers, try to keep the plants growing all summer long, and then they will flower again in fall. In short summer seasons, start them in paper pots so that they can be planted without disturbing their roots.
The flowers are tubular and come in lovely oranges, reds, yellows, creams, and russets. There are some bicolors too.
Look at the type of seed that you are buying. There are those that make clumps, and there are others that make long runners.
In general, tiny seeds need light and should be sown close to or on the surface, and large seeds need to be buried below ground to about two to three times their width.
- Cool season annuals thrive when the soil and the air temperatures are above freezing, but not yet hot. In cool summer climates, these may keep flowering all summer.
- Warm-season annuals are only planted at the same time as you would put out tomatoes and other warm-season vegetables. The soil should be at least sixty degrees Fahrenheit. To know when to plant your different annual types, you need to find out approximately when your last frost is predicted. As we know, this is an expected last frost date.
If you have already sown your seeds and the weather turns cold again, you can always cover up outside beds with an old sheet or tablecloth, and remove it when it warms back up. Seeds growing outside in containers can also be covered or moved into a garage or porch.
7 Easy & Fast Flowers To Grow From Seed. Beginner Friendly Annual Flowers!
FAQ
Is it too late to plant flower seeds in April?
Any time in spring is almost never too late. The exception is if you want a specific cool-season crop, and then odds are good you’re just too early for fall.
Can I just throw flower seeds on the ground?
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Preparation is Key:While you can just toss seeds, preparing the soil beforehand significantly increases your chances of success.
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Loosen the Soil:Loosening the top layer of soil with a rake or similar tool allows the seeds to make better contact and helps with root growth.
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Scattering and Raking:After loosening the soil, scatter the seeds thinly and evenly. Then, lightly rake the area to cover the seeds with a thin layer of soil.
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Don’t Bury Too Deep:Many wildflower seeds need light to germinate, so avoid burying them too deeply.
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Watering:Water the area gently after planting to help the seeds settle and germinate.
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Weed Control:Removing existing weeds and grass before planting will give your wildflowers a better chance to thrive by reducing competition for resources like water and nutrients.
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Consider Native Species:Choosing native wildflowers to your area is a great way to ensure they thrive and support local pollinators.
What is the best month to plant flower seeds?
- In the very early Spring (end of January to March) you can sow hardy annual seeds. …
- From March to June you can sow half-hardy annual seeds. …
- In June and July it’s time for the biennials.
What month do you plant flowers in spring?
However, as a general rule, it’s best to hold off on planting until after the last frost, typically between mid-April and early May. This way, your beloved flowers have a better chance of thriving in slightly warmer temperatures. A good tip is to plant seasonal flowers for your Mom on Mother’s Day!