quick growing flowers from seeds

The Fastest Growing Flower Seeds

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If you are a new gardener or are working on a garden project with children, finding flower seeds that grow rapidly is important. The fastest-growing seeds germinate in a matter of days and flower in roughly two months. An important consideration for very young children is seed size, which should be big enough to pick up easily between thumb and finger, such as a nasturtium or sunflower seeds. In contrast, petunia seed is fine as dust.

Germination vs. Bloom Time

Some flower seeds, such as zinnias (Zinnia spp.), may germinate a few days after planting. Zinnias average from three to five days. However, that doesn’t mean they are among the fastest-growing flowers, because it can take zinnias 75 to 90 days to flower. Cosmos (Cosmos spp.) is another prime example. Although its seed germinates in seven to 10 days, cosmos doesn’t flower until 90 to 120 days after planting. In contrast, California poppy (Eschscholzia californica) may take about 21 days to germinate in U.S. Department of Agriculture plant hardiness zones 6 to 10, but flowers within 60. The fastest-growing flower seeds are those that germinate in 14 days or less and flower within 70 days. These include marigold (Tagetes spp.), nasturtium (Tropaeolum majus), annual phlox (Phlox drummondii) and sunflowers (Helianthus spp.). Aside from its genetic heritage, the speed of a flower’s growth depends on having its needs met. In the beginning, these conditions include seed planting depth and other germination concerns, such as light, temperature and moisture.

Impact of Seed Planting Depth

Planting a seed incorrectly can impede or end growth. Some seeds need light to germinate and must be sown on top of their growing medium, whether outdoors in the garden or indoors on seed flats. These include impatiens (Impatiens spp.) and petunias (Petunia spp.). For seeds that need darkness – such as those of calendula (Calendula spp.), phlox and sunflowers – a general rule is to plant at a depth twice the seed’s diameter. For example, large sunflower seeds require planting 1 1/2 to 2 1/2 inches deep. Marigolds, however, germinate whether planted under or on top of soil. Check seed packets for information about planting depth.

Other Needs for Quick Germination

Proper germination temperature and moisture also speed initial growth. Temperature requirements vary for the seeds of different plants. For example, the optimum daytime germination temperature for marigolds is 70 degrees Fahrenheit whereas snapdragons (Antirrhinum spp.) like it colder at 65 F. For most flower seeds, the daytime temperature needs to be somewhere between 60 to 80 F, and nighttime temperatures should be 10 to 15 degrees cooler. For indoor seed starting, if you feel comfortable with the temperature in your house, your seeds likely will too. Moisten the soil before planting, because watering immediately after sowing can cause seeds and soil to shift haphazardly. Keep the soil moist but not soggy during germination to avoid rot.

Seeding Location and Growth

Some plants do better if seeded outdoors. If seeded indoors, transplanting may slow their growth. These plants include cosmos, marigolds, nasturtium, sunflowers and zinnias. The rule for seeding outdoors is to wait until the threat of frost has passed. Flowers that do better when seeded indoors include impatiens and petunias. For seeds planted indoors, the growth time different flowers need before outdoor transplanting varies. Although impatiens may not be ready for transplanting until about eight weeks old, zinnias started indoors will become leggy and root-bound if kept inside that long. Consequently, if starting seeds indoors, you need to time germination based on a transplanting date when the danger of frost will have passed.

The Fastest Growing Flower Seeds. If you are a new gardener or are working on a garden project with children, finding flower seeds that grow rapidly is important. The fastest-growing seeds germinate in a matter of days and flower in roughly two months. An important consideration for very young children is seed size, …

Top 10 easy to grow flowers

Do your neighbours’ borders burgeon with colour, and their containers drip with flowers while yours look brown and crispy?

The fact is that some garden plants are easier to grow from seed than others – but your neighbour probably knows that already! Read our list of top 10 easy to grow garden plants and discover the secret to a hassle-free, flower-filled summer garden.

Read on to find out more about the easiest flower plants to grow from seed, or scroll down to see the full infographic at the bottom of the page.


Always a favourite with kids – they’ll definitely be impressed with Sunflower ‘Mongolian Giant’ growing up to 14 feet tall! Just sow the seeds straight into the ground in a sunny, sheltered spot and watch them grow and grow and grow! Be sure to provide the stems with supports to grow the tallest sunflowers around.

Sweet Peas

Irresistable fragrance and prettiness! And the more you pick, the more flowers they produce! The large seeds of sweet peas are easy to handle, but if sowing sounds complicated then buy them as sweet pea plug plants! A sunny spot, a supportive fence, and regular watering is all these climbers need to produce your own ‘home grown’ cut flowers. Just keep an eye out for mice, slugs and snails – they love the young shoots. Consider covering with a mini cloche, or even a cut-off plastic bottle.

Nigella (Love in A Mist)

Nigella is an incredibly easy plant to grow. Simply scatter nigella seed across a patch of bare soil and let it look after itself! With jewel-like flowers and delicate ferny leaves, nigella is much tougher than it looks. As the flowers fade, this pretty plant will set seed for the following year. What could be simpler!


Aquilegias are easy plants to grow from seeds and will come back year after year. Start aquilegias in small pots for transplanting later on. Once they’re established they’ll self-seed, so you’ll always have fresh plants each year. They tolerate almost any conditions in sun or semi-shade, and their pretty bonnet-like flowers come in almost every imaginable colour combination.

Eschscholzia (Californian Poppy)

If you are not a fan of watering then Eschscholzia make easy to grow plants for your garden. These colourful little annuals thrive in poor, dry soil and full sun so they are perfect for filling forgotten corners of the garden. Just scatter them where you want them to flower and let them take care of themselves. Each year they will set seed which will grow the following summer, creating effortless drifts of colour.


Quick-growing and colourful, nasturtiums are easy plants for children to grow. Sow them in borders as ground cover or let them spill out of containers. The large seeds can be sown directly into the soil – just wait until after the last frosts. Their peppery leaves and flowers complement and garnish summer salads.


These easy to grow bedding plants are another great choice for young gardeners. Marigold seeds are easy to handle, and grow quickly so you’ll have a short wait for their colourful flowers. From tall varieties for the border to small types for beds and containers, there’s a marigold to suit every sunny spot in the garden.

Hardy Geranium (Cranesbill)

Cranesbill is so popular because it’s a reliable, low maintenance, ground cover that will wander through your borders year after year. Hardy geraniums are not difficult to grow from seed but you can grow them from bareroots which is even simpler.


Easy to grow patio plants when grown from plugs, and best loved for adding colour to hanging baskets and containers. Fuchsias come in all colours and shapes, from trailing to upright you could even try the climbing fuchsia ‘Lady Boothby’ for an ambitious display. For a really professional look, pinch out the very tips of each stem while the plants are still young to encourage lots of bushy growth. Fuchsia erries are edible, but not always tasty!


With their cheery faces, it’s hard to resist the appeal of pansies. These garden favourites are easy plants to grow from seed but even easier from pansy plug plants. Whether you grow them for winter or summer colour, deadheading faded flowers will encourage more and more colourful blooms.

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Written by: Sue Sanderson


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Read our top 10 list of easy to grow flowers to find the secret of a hassle-free summer garden. T&M’s guide reveals which ones are easy to grow.