7 flower bulbs to plant in March for a stunning summer display

Planting summer bulbs in March gives your summer garden a genuine head start. The soil is slowly warming up, yet it still holds plenty of moisture - exactly what many summer‑flowering bulb plants relish. With the right choices and good timing, you can stretch the flowering season from June right through to October.

Why March is a golden window for summer bulbs

In March, the garden often still looks wintry above ground. Beneath the surface, however, plants are already busy: the soil is well moistened by months of rain, and temperatures edge up a little more each week.

"Planting summer bulbs in March gives them time to build a strong root network - which later makes them more resilient during heat and dry spells."

Depending on the area, the ideal starting point shifts slightly:

• Mild regions / wine‑growing climates / suburban locations: planting can often begin in early March.
• Central Germany: usually best from mid‑ to late March.
• Cool areas / higher elevations: more like early April - or start in pots under glass beforehand.

Where late frosts are likely, cover fresh shoots in the evening with horticultural fleece. A thin mulch layer of leaves or bark chips also helps smooth out temperature swings.

How to plant flower bulbs (summer bulbs) properly in March

Before you start, check the planting material closely. Firm, plump bulbs with no rotten patches or mould get going far more reliably than soft or shrivelled ones.

Site and soil: what works best

Most summer‑flowering bulbs do best with:

• Loose, free‑draining soil: waterlogging is disastrous, especially in spring.
• Plenty of nutrients: mature compost as a starter feed can make a big difference.
• A sunny position: especially for varieties with showy blooms that need long hours of light.

If your soil is heavy, improve it with sand or fine grit. If rainwater regularly sits in puddles for a long time, that spot isn’t suitable for bulb plants.

A simple depth rule that nearly always works

A handy rule of thumb for planting depth is easy to remember:

Planting depth = roughly 2.5 to 3 times the bulb’s height.

For example, if a bulb is 5 centimetres tall, plant it 12 to 15 centimetres deep. Position the pointed end upwards. After planting, gently firm the soil and water thoroughly once.

Taller varieties with long flower stems benefit from a support cane put in at planting time. That way, shoots are less likely to snap in wind or flop over in heavy rain.

Seven standout summer bulbs that really deliver

With the seven choices below, you can design a bed that keeps showing colour from June into autumn - without needing to water every single day.

Dahlias: a colour explosion right into October

Dahlias are a firm favourite with many gardeners. Depending on the cultivar, they flower from high summer well into late autumn. Planted in March or April into well‑drained soil, they develop into strong, bushy plants covered in blooms - from simple forms to pompon shapes.

• Position: full sun, sheltered from wind.
• Spacing: depending on the variety, 40 to 80 centimetres.
• Tip: deadheading spent flowers regularly encourages fresh buds.

In frost‑prone areas, it’s worth starting the tubers in pots indoors or in a greenhouse first. Once the last frosts have passed, move the plants out into the ground.

Lilies: elegant scent and strong vertical interest

Lilies add structure to perennial borders. Their flowers usually open between June and August and, depending on the type, can be lightly to strongly scented. They prefer being planted deep so the bulbs stay cool and stable.

• Position: a bright spot, ideally with the “feet” lightly shaded by low perennials.
• Planting depth: typically 15 to 20 centimetres.
• Tip: a little sand beneath the bulb helps prevent rot.

They work particularly well in mixed beds, rising above a base layer of perennials and ornamental grasses.

Tuber begonias: bright colour for shady spots

Tuberous begonias are specialists for part shade to shade. Where many summer flowers struggle, they bring colour to window boxes, pots and border edges - usually from July into autumn.

• Position: part shade to shade, sheltered from wind.
• Use: ideal for balcony boxes, hanging baskets and shady front gardens.
• Tip: start them indoors in pots in March, then put them outside from May.

Set the tuber shallowly with the slightly hollowed side facing upwards. A loose compost that never becomes completely waterlogged reduces the risk of rot.

Gladioli: dramatic flower spikes for cutting

Gladioli are the classic cut flowers from grandma’s garden - and they’re enjoying a comeback. Their tall spikes create bold highlights in borders and cottage gardens.

• Position: sunny, in a sheltered spot.
• Staggered planting: planting new corms every two weeks extends the flowering period.
• Tip: push in a stake at planting time for support.

Because gladioli can snap in strong winds, they do best in front of walls or hedges. In narrow beds, you can place them behind low perennials so only the flower spikes stand above.

Cannas: a tropical feel by the patio

Cannas (often called canna lilies) bring an instant holiday mood with their broad leaves - often richly coloured - and large flowers. They look especially striking in big containers.

• Position: full sun, warm, and out of the wind.
• Soil: nutrient‑rich and evenly moist, but not wet.
• Tip: start in a pot indoors in March, then move outdoors after the mid‑May frost risk has passed.

In cooler regions, lift and store the rhizomes frost‑free in a cellar or garage over winter. In spring, you can divide them to create new plants.

Crocosmia: fiery arches for late summer

Crocosmias (often sold under the name montbretia) stand out for their arched stems of orange, red or yellow flowers. They add movement to borders and suit more naturalistic garden styles.

• Position: sun to part shade.
• Planting: set them in groups for the best colour impact.
• Tip: a light winter mulch of leaves helps them through severe cold spells.

Their fine foliage and arching habit create attractive contrasts with compact perennials or grasses.

Agapanthus: globe blooms for enthusiasts

Agapanthus (African lily) produces large, spherical flower heads in white or blue during summer. In many gardens it’s grown in pots, as it isn’t reliably hardy everywhere.

• Position: sun, ideally against a warm house wall.
• Container growing: slightly crowded roots tend to boost flowering.
• Tip: overwinter somewhere bright and frost‑free, watering sparingly.

In mild areas, tougher varieties can also be planted in the ground, but free‑draining soil and winter protection are essential.

How to combine the seven types for a long run of flowers

To avoid a brief burst of colour and instead keep things interesting for months, it helps to sketch out a simple flowering plan. One workable sequence looks like this:

Month	Typical bloomers from this selection
June	Lilies, early gladioli, first agapanthus varieties
July	Dahlias, begonias, gladioli, cannas, agapanthus
August	Dahlias, cannas, crocosmia, begonias
September/October	Dahlias, late begonias, remaining flowers on cannas

For a balanced look in the border, place taller plants such as dahlias, gladioli and cannas towards the back. Crocosmia and lilies suit the middle, while begonias and smaller agapanthus varieties work well at the front.

Practical extras: feeding, watering and common mistakes

Summer bulbs are fairly forgiving as long as a few basics are right:

• Water moderately but deeply: better to soak occasionally than to sprinkle a little every day.
• Nutrient top‑up: one application of organic fertiliser or compost in spring is usually enough.
• Remove spent blooms: this directs energy into new buds rather than seed production.

The most common problems are soil that stays too wet, planting out too early where frost is still a risk, and spacing plants too closely. Ignoring the distances on the packet can invite fungal diseases and lead to weak growth.

What amateur gardeners should know before next season

Many summer‑flowering bulbs and tubers are not fully winter hardy. In harsher areas, for instance, dahlia tubers, cannas and some gladiolus varieties are lifted in autumn and placed into boxes filled with slightly moist growing medium. Stored cool, frost‑free and dark, they’ll last until spring.

From a gardening point of view, that small extra effort pays off: once bought, most of these plants can stay with you for many years. Each season you can divide them, reposition them, and try new colour contrasts - gradually shaping your own summer garden that begins in March, both on paper and in the soil.