The delphinium is one of the absolute classics in the garden. Here's everything you need to know about planting and caring for this popular perennial.

Lelphinium (Delphinium) adds a wonderful color to any garden and its botanical name already suggests that the flowers of the larkspur resemble a dolphin. The tall ornamental plants are an integral part of many gardens - we explain what else you should know about these beautiful plants.
The delphinium belongs to the buttercup family (Ranunculaceae) and is one of the best known and certainly most beautiful perennials that we can put in our gardens. But what maybe not everyone knows is that delphiniums are poisonous plants because the alkaloids they contain (elatin, delphinine and others) make the plants and especially their seeds extremely poisonous. This property even earned delphinium the title of "Poisonous Plant of the Year" in 2015.
Larkspur: origin and characteristics
The various types of delphiniums come either from the Mediterranean or from Asia. Larkspur has erect stems that are sometimes branched. Wonderful single or double flowers then grow on these stems - making them a striking ornament for your garden. With its wonderful flowers, delphinium is also ideal as a cut flower or for drying. Delphiniums come in white, pink, red, blue, and purple flower colors. These flower colors are of course available in a wide variety of color gradations and you can marvel at the blooming of delphiniums from June to August.
The larkspurs can vary greatly in size, because the smallest species only reach a height of about 20 centimeters. However, some delphiniums manage to grow to a height of as much as two meters. Such an ornamental plant looks great in the garden, of course, but also requires extra maintenance - such tall plants are always at risk of tipping over, especially in strong winds. You also have to be careful with themLarkspur bed neighbors, because not every plant is suitable for it. Suitable neighbors for delphiniums are bluebells (Campanula lactiflora), irises (Iris barbata), daisies (Chrysanthemum maximum ), cranesbill (Geranium) or yarrow (Achillea filipendulina). It is even said that irises promote the growth of delphiniums. On the other hand, you should avoid planting phlox (Phlox) and asters (Aster) near delphiniums, as the roots of these plants do not understand each other and damage underground.

Larkspur Species
There are many different types of delphiniums, varying in size, color and area of origin. There are an estimated 400 different species of delphiniums, most of which come from different parts of Europe. Delphiniums can be subdivided botanically or according to the crossing types or hybrid varieties.
Larkspur: Botanical Distinction
- Garden Larkspur or Hyacinth Larkspur (Consolida ajacis)
- Field Larkspur or Field Larkspur (Consolida regalis)
- Pygmy Larkspur (Delphinium grandiflorum)
As you can already see from the different species names, the systematics in the delphinium genus is very complicated and some of the species names have also changed in recent years. Such modifications are the result of more precise analysis methods, since molecular biology can be used to determine relationships among different plants more precisely than in the past, when the system was created solely based on the appearance of the plants.
In breeders' circles, a distinction is made between the following delphinium species or delphinium hybrids:
- Elatum Group (Tall Garden Larkspur)
- Pacific Group (Pacific Larkspur)
- Belladonna Group (Half-tall Larkspur)
The wild delphiniums are usually only annuals or biennials, whereas cultivated garden forms are often more long-lived. It is generally said that the taller a delphinium grows, the longer it lives. For example, Pacific varieties only live up to three years, Belladonna varieties can live up to five years, and Elatum varieties even manage to live up to ten years.
Buying delphiniums: you should pay attention to this
If you are in theare a nursery and want to grow a new delphinium plant, you should pay attention to a few small things in order to take the best possible plant home with you. So you should stay away from delphiniums that are already in full bloom in the nursery, because these plants will grow very poorly in your garden. It is of course very tempting to buy such a beautiful flowering delphinium plant, but you will not get much pleasure from it. Otherwise, you should of course - as with all purchased plants - also pay attention to the he alth of the plants, because after all you don't want to bring diseases and pests into the garden. It is therefore important that you make sure that there is no fungal coating on the leaves. You should also check the plants for pests. The eggs are often found on the underside of the leaves or you can see signs of feeding on the leaves. Therefore, always check each plant for damage, leaf discoloration, or other symptoms before purchasing.
Of course, when it comes to buying delphiniums, we cannot avoid Karl Foerster, who was a well-known gardener and perennial grower and grew countless wonderful delphiniums. Karl Foerster died in 1970, but his varieties survived him and of course you can buy them in many nurseries, including Foerster-Stauden in Potsdam-Bornim.
Plant Larkspur
Larkspurs need a lot of nutrients and therefore you have to move them again and again so that the soil is not leached too much. Below you will find a few points that you should consider when planting delphiniums so that you can enjoy the beautiful ornamental plants for a long time.

The perfect location for Larkspur
In order for delphiniums to grow optimally, they need a sunny spot in your garden where they are protected from the wind. However, the delphinium does not want to stand in the blazing sun, because it prefers the sun on its head and shade on its feet, as the saying goes. It is therefore advisable to place other low-growing ornamental plants around the delphinium that can provide shade. The delphinium prefers a loamy, humus-rich soil that should be nutrient-rich and deep, but low in nitrogen. So that a sown delphinium can germinate, it needs a cool soil temperature of 10 to 12 °C.
The right way to plant delphiniums
Larkspurs canbe sown outdoors either in autumn to mid-October or in spring in the months of March and April. You can also sow the delphiniums in boxes and pots indoors from the end of March and prefer them. This gives the plants a head start in growth and protects them from pests and diseases when they emerge. In addition, delphiniums that have been brought forward are also protected from frost events in this way, since they are not planted out until mid-May. You should keep a planting distance of 15 to 30 centimeters.
How to properly plant delphiniums?
- Water delphinium root ball before planting
- Dig a hole big enough for the root ball
- Add fertilizer such as manure or compost to the planting hole
- Put the delphinium in the hole
- Make sure the delphinium root ball is flush with the ground
- Fill in the hole with the excavated earth
- Press down the earth around the larkspur
- Water the delphinium thoroughly
Care for Larkspur
So that you can enjoy your delphiniums all summer long, you should pay attention to a few things when caring for these plants. Due to their height, delphiniums are very susceptible to wind, which is why you should always look for a place that is protected from the wind for your delphiniums, otherwise there is a risk of them buckling or being blown over. Optimum care also includes pruning delphiniums in summer. Once the delphinium has flowered, you should shorten the stems to 20 centimeters. The plant will rejuvenate and sprout again. You can therefore expect a second flowering in late summer. Pruning is also recommended to prevent delphiniums from growing very tall, because the taller the delphinium stalks are, the more susceptible they are to wind. Do not cut the delphinium deeper than 20 centimeters, otherwise it may no longer be able to sprout.
Watering Larkspur
Delphiniums must be watered sufficiently and regularly for optimal development, as larkspurs have a very high water requirement. If the weather is very hot and there are severe dry spells, you should water the delphinium at least once a day, if not twice. To avoid excessive water evaporation, you can spread a layer of mulch around the delphinium or create shade with ground-covering plants.

Fertilize Larkspur
It is highly recommended to add some fertilizer such as compost to the soil before planting or sowing. Rotten horse manure is also particularly suitable for fertilizing delphiniums. Since the plants are shallow-rooted, you only need to put the fertilizer about 40 centimeters into the soil. It is advisable to fertilize perennial delphiniums organically twice a year, with it being ideal to fertilize organically once in spring before they sprout and once in autumn after pruning. For example, organic means such as your own compost are suitable as fertilizer. You can also use our Plantura organic flower fertilizer to provide your delphinium with sufficient nutrients so that it survives the winter protected.
Compost, manure or other organic fertilizers should always be worked into the soil carefully, being careful not to damage the roots of the plants. The advantage of organic fertilization in autumn is that the fertilizer can already decompose a little, is broken down and thus guarantees your plants a strong start next spring. If you use mineral fertilizers for your larkspur, it is advisable to always pay attention to the instructions for use and especially to the dosage. You can find out more about mineral fertilizers in our special article.
Increase Larkspur
The delphinium sows itself if you let the infructescence fully ripen. If you are not satisfied with this individual sowing, you can also use another variant. Nowadays, delphiniums are usually propagated by dividing the stick.
What is the best way to divide delphiniums to propagate?
- Dig up your delphinium
- Use a spade to split the root ball
- Place the divided root ball in a bucket of water
- Dig a planting hole and loosen the soil in it
- Mix compost into the burrow
- Put the delphinium in the planting hole as described above
Larkspurs are divided in spring, the month of April is best for this. In the best-case scenario, these delphiniums bloom in the same autumn or in the next spring and delight our eyes with their wonderful blooms. Of course, you can also propagate delphiniums from seeds, which you can then use wholejust sow again. You must not cut back the delphinium for this, you must let it wither so that the seeds can form. It is important not to cut back delphiniums after the first flowering so that the seeds have enough time to ripen. It then develops follicles, which then contain characteristic triangular seeds. You can now collect these fruits when they have turned brown and are dry - but you must collect them before the fruits burst open and seed themselves.

You should dry the collected fruit if necessary. The seeds must then be cleaned and stored in a dry and dark place. In spring you can then pull the seeds forward from March or sow them directly into the ground from May. If you propagate hybrid larkspur yourself, subsequent generations will have different characteristics and appearance from the parent plants - but this is a great way to introduce some diversity into your garden.
Overwinter Larkspur
Larkspurs outdoors do not need any special winter protection, apart from cutting them back in autumn and adding another dose of compost. This treatment is sufficient for perennial delphiniums so that they sprout again in spring. For annuals and biennials, you should either sow them yourself or collect the seeds.
However, plants grown in containers need protection to survive the winter. These are more sensitive and should be protected against frost as follows:
- Wrap the tubs with fleece
- Place the tubs in a sheltered place, for example on a house wall or in a corner
- Place the buckets on styrofoam or wood to keep the cold off the ground
- Cover the plants with sticks or leaves
Here you can find out more about overwintering different plants and which of them can survive our winter without any problems.
Frequent diseases and pests of delphiniums
Our delphinium is also repeatedly threatened by various animal pests. Slugs (Gastropoda), leafminers (Agromyzidae) and Christmas mites (Tarsonemidae) infest it particularly often . But some diseases also occur on delphiniums, such as black bacteria (Pseudomonasdelphinii), powdery mildew (Erysiphaceae) or viruses. The occurrence of pests and diseases is often promoted by an unsuitable location - with delphiniums this is often too shady. You can use plant manure as a preventive measure to strengthen delphiniums. If the delphinium is attacked by fungi such as powdery mildew, you can simply cut off the affected shoots and thus contain the infestation.