The Fastest-Growing Flower Seeds

Imagine a vibrant garden filled with your favourite flowers. But before you know it, the perfect time for planting might have passed. Don’t let that happen, and step into your garden shed.

It doesn’t matter if you don’t have the time to garden and put the effort into it. Here, we’ll explore the fastest-growing flower seeds that will have your yard blooming in no time! Let’s dive in and ensure you effortlessly make the most of your garden.

1. Cornflowers


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Cornflowers are the epitome of simplicity and affordability when it comes to gardening. These beauties can reach a height of up to 10 inches. What’s more, they come with striking blooms in various shades of blue, pink, white, red, lavender, and maroon.

To ensure successful growth, opt for slightly alkaline garden soil when planting. Regularly water the seeds until germination. It typically takes around seven to ten days for annuals and two to four weeks for perennials.

For an indoor option, such as in a greenhouse, sow the cornflower seeds about a month before the last frost. Or one month before transplanting them outdoors. This approach makes it equally effortless to enjoy these lovely flowers.

2. Poppies


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Offering a wide range of varieties, poppies captivate with their quick growth. Consider growing the majestic Oriental poppy, reaching up to four feet in height. Or charm your garden with an Alpine poppy standing at around ten inches!

You won’t have to wait long to witness the enchanting colours of poppies. Their seeds typically sprout in just 8 to 15 days, ensuring swift gratification.

Plant poppies in well-draining soil and water and feed them regularly throughout summer. Be cautious not to overwater, as excess moisture in cool, wet conditions can lead to rotting.

3. Marigolds


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Embodying speed and ease, marigolds emerge as fast-growing flowers. Their beauty boasts vibrant hues of yellow, orange, and mahogany. Within a mere eight weeks of sowing, these delightful blooms grace your garden.

Ensure your marigolds bask in at least six hours of sunlight daily. Plant the seeds 1/4 inch deep into the soil and space them accordingly. Ideally, with 6-9 inches apart for French marigolds. As for larger African marigolds, around 18 inches is recommended. Keep the soil consistently moist after planting. And voila! Your marigold seeds should sprout within five to seven days.

4. Sweet pea

Sweat pea

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Sweet peas are prized for their rapid growth. They can transform from seedlings to flowering plants in just three to four months!

For faster results, consider using starts instead of seeds. Plant sweet peas in the fall to enjoy winter blooms as they struggle in hot, humid weather. Optimal temperatures around 23°C are ideal for their growth.

As natural climbers, provide a garden arch trellis to reach their full potential. Without support, they will grow bushy and low. Sweet peas can reach heights of three to eight feet with a spread of two to three feet. This, as a result, can add a touch of beauty and elegance to your garden!

5. Sunflowers


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Sunflower is a well-known and surprisingly quick-sprouting flower in the UK. Its seeds typically sprout within seven to ten days. While the dazzling shades of yellow, orange, red, bronze, and brown take approx. two months to bloom, it’s still a swift process.

Sunflowers bring vibrant colours and joy to the landscape. Even better, they attract pollinators, providing seeds for snacks (yum!) and creating a stunning focal point in any garden.

If you’re interested in enjoying the seeds as a healthy snack, allow an additional month for them to mature. Depending on the climate and cultivation, sunflowers can grow three to six feet tall. Ensure they receive ample sunlight while protecting them from harsh winds.

6. Petunias


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Petunias offer a burst of colour and charm with their abundant blooms. Starting from seeds, petunias take around ten weeks to grow fully. These sun-loving flowers prefer full sunlight but can tolerate some shade if necessary.

Older varieties of petunias require diligent deadheading to continue blooming. Meanwhile, newer varieties don’t need deadheading; occasional pinching or shearing helps.

Be prepared for sticky foliage, and remove recently rained-on blossoms promptly. Keep an eye on the branches’ length and pinch or shear when necessary to encourage healthy growth.

7. Nigella


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Also known as Love-in-a-Mist, Nigella boasts enchanting flowers in the shades of:

  • purple
  • pink
  • white
  • blue

It’s known for its quick sprouting times of just 8 to 15 days. Plus, it’s an effortless flower to grow in cool areas with well-drained, pH-neutral soil. The seeds boast remarkable sprouting times of just eight to fifteen days. For best results, plant them from late April onward, with 30cm spacing between each plant.

Consider sowing the seeds multiple times between late spring and early summer. Doing so will enable you to enjoy the vibrant colours of purple, pink, white, and blue in your garden in a matter of weeks. With its charm and swift growth, Nigella adds a touch of mystery and beauty to any landscape.

8. Zinnias


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Zinnias are known for their rapid growth and vibrant, multi-coloured blooms. These annual flowers are easy to grow from seeds and typically sprout within 7 to 10 days.

Zinnias thrive in full sun and well-draining soil, making them ideal for hot and dry climates. Regular deadheading encourages continuous blooming throughout the season.

With various shapes and sizes available, they create a lively display in landscapes. What’s more, they attract butterflies and hummingbirds, perfect for wildlife garden ideas.

9. Cosmos


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Cosmos delight with their daisy-like blossoms in shades of pink, white, and red. These low-maintenance plants prefer full sun and well-draining soil. They can even thrive in poor soil conditions.

Cosmos seeds germinate within 7 to 21 days, and the plants can reach heights up to 2-4 feet. Deadheading spent flowers promotes prolonged blooming. This makes the cosmos a beautiful and effortless addition to your garden landscape.

10. Alyssum


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Alyssum is a quick-growing flower known for its sweet fragrance. Its delicate clusters of white, pink, or purple blooms add to its charm.

These annuals are easy to grow from seeds, with germination occurring within 5 to 10 days. Alyssum thrives in full sun to partial shade and well-draining soil. These low-growing flowers make charming border plants or ground covers.

They attract pollinators and resist deer and rabbit browsing, to add. This makes Alyssum beneficial to any garden while adding a touch of beauty.


Planting fast-growing seeds to jumpstart your gardening journey may seem appealing. Yet, it’s crucial to understand the rules and regulations that come with it. Being aware of property boundaries and potential limitations for certain plants is essential.

Gardening can be challenging, and maintaining a garden can be even harder. However, with the aid of a wooden shed or greenhouse, you can simplify the process. Let your garden flourish and achieve a productive small wildlife garden. Growing a sustainable garden is also worthwhile. Happy gardening!

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