Annual plants with rapid growth: a flowering garden in record time

Why choose annual plants for the garden?

Annuals differ from other plants by their very short life cycle, which lasts only a few months. In less than a year they move from germination to flowering, then to fruiting to reproduce, before withering and dying. This explains why they can be very floriferous for many months and grow very quickly: they have no time to waste when it comes to living and reproducing. Some can literally grow several metres in a few weeks. They are therefore among the fastest-growing plants. This trait makes them ideal for creating an immediate impact in the garden or for quickly dressing a dull, unattractive area.

Ephemeral, annuals can be replaced each year to create quick new displays. But if you like them, don’t hesitate to let them self-seed. If growing conditions suit them, many will come back spontaneously the following year.

But that isn’t their only virtue. Beyond their flowering, they also offer other ornamental benefits: colourful or striking foliage, scented blooms, decorative fruiting, etc. There are many varieties capable of satisfying all tastes and fitting into every garden style, from modern and contemporary to romantic, including bohemian, naturalistic or exotic settings. With so many different silhouettes, flower shapes, colours and foliage, you will certainly find annuals to suit you.

Note also that many of them favour the presence of pollinating insects, such as bees or butterflies.

Remember that annuals are among the easiest plants to succeed with, even from sowing. If you want to take up gardening, watching them develop from a tiny seedling to a fully flowering plant is particularly rewarding for adults as well as children. Annuals are also economical: they often cost less to buy than perennials because they require less long-term care. It is also possible to collect seeds from one year to the next to multiply them for free.

Have we convinced you? Now let’s see how to choose among fast-growing annuals.

Who doesn’t want fast-growing plants!

How to choose fast-growing annual plants?

Before diving blindly into choosing fast-growing annuals, it’s essential to know your growing constraints. Putting the right plant in the right place is sound advice often heard. Put simply, don’t grow a plant that prefers moisture and low light in the full sun of the south in dry soil.

So make sure you know:

• what type of soil you have (fertile or poor in organic matter, heavy or light, dry or moist, acidic or calcareous);
• what the climate and environmental conditions of the region are, especially in spring and summer for annuals (long winters, frequent summer droughts, persistent moisture, strong winds…);
• how the garden is exposed (sunny, dappled light, shaded, etc.);
• the available space (small border, large flower bed, container…).

Once you’ve identified these specifics, you can choose annuals that suit those conditions. It’s key to successful planting, avoiding wasting time or money on unnecessary care. To help you, discover our Plantfit app, which allows you to create a personalised profile of your outdoor space.

Annual plants with rapid growth according to use

These annuals will either germinate very quickly (germination within 10 to 18 days on average) or grow several metres in a few weeks. Choose them according to intended use.

For a small border or a fast-growing rockery

To dress a border quickly, choose small, low-growing or groundcover annuals that flower fast. This is the case for Tagetes (French marigolds) with their warm colours, which brighten the garden. They form true little flowering cushions until first frosts.

Likewise, forget-me-nots will create beautiful groundcover of intense blue within a few months. Some varieties are also available in pink or white.

With their delicate blooms, alyssum also enhance a border or rockery in just a few months.

To cover a rockery or bank quickly, consider nasturtiums, a flexible annual that can spread rapidly over 2 metres if no support is available for climbing.

For an express flowering bed

To flower a sunny bed quickly, you will be spoilt for choice. Start with Flanders poppies, which have the advantage of flowering quite early, sometimes from May or June.

Just as speedy, the California poppy brings a zing with its bright orange. When it self-seeds and is well exposed, it can appear as early as March in mild southern regions with an early spring.

Do not forget the wild, melliferous flowering of centaureas, essential in a cottage-style bed, or the long-lasting, colourful blooms of China asters.

Reaching quickly up to 1 metre in height and offering very long-lasting flowers, bracteate everlastings are also wonderful for dried bouquets.

Able to germinate in less than 10 days, pot marigold (Calendula) is also among these express annuals, showing attractive blooms for many months with little care.

Nigella damascena (love-in-a-mist) combines ornamental qualities: rapid growth, summer-long flowering, and an elegant finely divided foliage. Its decorative fruiting capsules then take over.

Love-in-a-mistCosmos performs beautifully for many months. In mild regions, it appears from mid-spring.

Of course, sunflowers are indispensable. They are not the earliest to flower, often waiting until mid-summer, but many bring height and volume to a bed quickly. Giant sunflowers can reach over 3 metres in a few weeks.

With its striking blooms, amaranth is also a great choice for creating rapid impact.

For foliage, ricinus common castor beans quickly produce large palmate leaves measuring 60–90 cm. This ultra-fast-growing plant can reach 2.5 metres in a single season — ideal for creating a lush, instant backdrop.

In shadier spots, consider begonias, which sometimes flower from May and continue for many months. Also think of impatiens, which flower quickly from late spring through to autumn. Don’t forget ornamental tobacco (Nicotiana), which quickly forms a clump that can exceed 1 metre and remains floriferous for months.

Ornamental tobacco

To screen quickly from view or sun

Looking for some privacy in the warm months or simple protection from sun rays? Turn to annual climbers without hesitation, which are among the fastest-growing plants. They can grow several metres in a few weeks, as with Ipomoea (morning glories) with their colourful trumpet flowers — perfect for dressing a fence or pergola.

Equally rapid and impressive, Rudbeckia (black-eyed Susans) flower from June to October and quickly reach nearly 2 metres. Similar performance from sweet peas.

Do not forget ornamental gourds, original with their decorative fruits.

Black-eyed Susan

To brighten terrace or balcony without delay

Fast-growing annuals are also perfect for creating lovely displays when you do not have a garden.

Again, begonias are ideal for quickly creating colourful container groups.

Want to play with colourful foliage? Grow Coleus, treated as annuals in our climate. Their variegated leaves are particularly striking and will enliven terraces, balconies, patios or sunny window sills. Pink, purple, yellow, green, red, maroon… colours combine to create eye-catching displays.

For a stunning hanging basket, choose Fuchsia, often grown as an annual because of limited hardiness.

And to save time and enjoy annuals even sooner, do not hesitate to start sowing indoors or use protective cloches or tunnels, which add a few degrees and thus hasten germination.