The delphiniums, commonly known as larkspur or dolphins, are typical flowers in some gardens. They are much appreciated for shaping meadow style backyards and are perfect for adding beautiful focal points in bedding, borders, or pots near the house. They are also considered to be the July flower.
Majestic but fragile, their long floral spikes, sometimes measuring nearly 2 meters, come in branched or dense spikes in pure blue, purple, white, yellow, pink, or red depending on the variety. They blossom in the sun, from June to October, depending on the design, in rich and deep soils.
Its majestic blooms produce beautiful bouquets. Today, we are going to discover how to plant and grow delphiniums.
* Botanical description
* Main features
* Where to plant?
* When and how to plant?
* Care and pruning
* Pests and diseases
* Floral association
Botanical Description
The genus delphinium is a perennial plant that belongs to the family of ranunculaceae and includes nearly 400 species. Most of them are perennials. There are a few annuals and biennials. The delphiniums owe their name to their flower buds extended by a long spur, which evokes the shape of a dolphin’s rostrum. These herbaceous and hardy plants are mostly native to temperate regions of the northern hemisphere.
Different delphinium cultivars are divided into various groups. The most commonly cultivated are grandiflorum larkspur cultivars, giant larkspur cultivars of the elatum group (up to 2 m at maturity), and Pacific hybrids.
Delphiniums have an upright bushy habit and form a graceful clump that ranges from 20 to 60 cm in diameter, depending on the species. Most larkspur feet have tough or fleshy, sometimes tuberous roots. It can take a few years for them to form beautiful clumps.
Main Features
These flowering perennials are always very noticeable in a garden: their majestic flowers bloom a few weeks from June to August and sometimes again in October. The floral scape is erect, and its height varies greatly depending on the species, from a few dozen centimeters to more than 2 meters.
Some very dense spikes are made up of many delicate flowers from 2 to 9 cm in diameter, cupped, single or double, spurred. The shape of the delphinium flower depends mainly on the size and color of the five large sepals; the real petals are much smaller. Many species and varieties of delphiniums offer a great variety of colors, but blue is the most frequent shade. From sky blue to cyan blue, from lavender to purple, from lilac to mauve, delphiniums are among the most beautiful blue flowers in the garden.
Where to Plant?
The delphinium is found almost everywhere except in very windy regions and dry, inadequate, or heavy soil. We strongly advise you to plant it where it can look beautiful and stunning.
The delphinium is not easy to grow. It is considerably demanding. It appreciates being planted on a sunny place, sheltered from strong winds. Plant them in a clear area, which can encourage the plant to give its entire height.
It fits into any decor, flowerbeds or borders, but it takes its full measure as a bedding plant. The tallest varieties are planted in the background of beds.
It likes fertile, deep, fresh soil, even in summer, and very well-drained. In poor soil, it can never be lush. In heavy and humid earth, it can develop and die or grow very slowly. If you wish to try the experiment, adding sand and gravel to the plant’s soil can help the delphinium to settle.
When and How to Plant?
Ideally, you should plant in autumn or spring in March – April after the last frosts. Plant in a sunny location, in deep, fresh ground, without excess limestone. If your soil is dense and compact, add topsoil and white peat at planting. Ideally, it is best to bury well-decomposed manure long before planting or natural organic fertilizer.
Plant in buckets, pots, or pails in groups of 3 to 5 feet per m2, spaced 0.40 to 0.75 cm apart depending on the variety. For a beautiful effect in a bed, it is preferable to plant in large numbers. As the foliage disappears in winter, it sounds a great idea to mark the position of the plants with a small stake so that you can keep an eye on snails and slugs in spring.
During growth, water once or twice a week, and apply liquid fertilizer every two to three weeks. In subsequent years, apply fertilizer in the spring.
Care and Pruning
Tall varieties should be staked firmly in the spring, as soon as they begin to grow. To ensure vigorous growth, cut off all sickly shoots at the collar level from April onwards.
Remove dying petals quickly after flowering to encourage a second flowering in the fall. As for annual varieties, let them seed to benefit from spontaneous sowing. If you wish to collect seeds, leave one spike per plant. After flowering, cut the wilted flower stems in half.
Preferably in the spring, when the plants start to grow, you should cut them down to the ground level to prevent water and moisture from penetrating the hollow stems during the winter, causing the tufts to rot.
The soil should be kept cool, and you should mulch and water regularly. The plants lose strength as they age and disappear quickly (often in three years): after five years, flowering becomes weak.
Pests and Diseases
The delphiniums have well-known enemies. First, snails and slugs that devour young shoots before they emerge from the ground in the spring. An anti-slug treatment, applied at planting and then every year from February onwards, is necessary.
Mildew and powdery mildew. As a preventive measure, spray Bordeaux mixture, sulfur and nettle, and horsetail manure. Do not leave residue of diseased plants on the ground; burn them.
Floral Association
Delphiniums are very easy to match. In most gardens, they are appreciated for their majestic bunches of flowers, white, pink, and, most importantly, the blue shade. They combine perfectly into natural gardens alongside oriental poppies, blueberries, and daisies to give a lovely combination. They are a must for sun gardens and of course, blue gardens.
Blue/golden, purple/lavender, or creamy yellow/soft orange, delphiniums are perfect plants to play with variations, distinctions, and degrees. Do not hesitate to transform a bed into a remarkable painting.
Delphiniums are among the most beautiful perennial plants. Their flowering lasts for more than a month. The flowers offer unique shades of blue and need sunlight to bloom. They are spectacular in the garden.
Delphiniums make very pretty bouquets of fresh flowers. Harvested when three-quarters of them are in bloom, the flower stems can remain beautiful in a vase for about two weeks. By letting them dry upside down, they can continue to brighten your interior in a bouquet of dried flowers.