Brightly colored and with a delicate floral scent – the summer lilac from the fig family has become more and more popular as a robust garden plant in recent years. And because the lilac, which can easily reach a height of two meters and a circumference of one meter, is a popular meeting place for butterflies, the plant is also known as “butterfly lilac”. The colors of the flower spikes vary from yellow to white and pink; even blue or purple species of buddleia are known. In the meantime, a total of around one hundred different types of the plant are available, all of which can easily be cultivated even by beginners.
Table of Contents
Choice of location and soil conditions
Warm, wide open spaces in the garden – this is where the butterfly lilac feels particularly at home. The plant thrives in sunny areas as well as in partial shade, so that the lilacs can be planted very variably. Optimal soil conditions are crucial when it comes to planting.
- light, dry and permeable
- contain many nutrients
- enrich the substrate with compost
- particularly damp or heavy soil is not suitable
- Lilac tolerates soil conditions, from acidic to calcareous
- When planting, make sure that the shrub thrives best as a single plant
- if necessary, a spot in front of dark trees is possible.
The lilac also looks great as a focal point in the perennial bed. Ideally, however, the plant is a little sheltered from the wind, because the delicate twigs bend slightly. At the onset of the cold season it has proven useful to also make the floor winter-proof. Over the years, the plant increases in frost resistance; nevertheless you should protect the plant additionally. Work here with an appropriate floor covering. Leaves and sticks are best for this purpose.
Watering, fertilizing and wintering
Even if the buddleia prefers dry locations – after planting, you need to water the plant regularly. The lilacs must always be kept moist, especially during the summer months. However, standing water should be avoided. The plant prefers calcareous water. Ordinary rainwater mixed with a little lime can therefore be used for watering. In addition, the lilac feels comfortable with a subtle fertilization. The best time for this is spring. After pruning, a nitrogenous fertilizer can now be added to the lilac.
The butterfly lilac sprouts anew every year, which is why additional protective measures in winter are only necessary for young plants that have not yet developed frost protection. The root area is covered with leaves and brushwood for this purpose. If the lilac is grown as a container plant, the young plant can also overwinter in a cool room.
Help with pests
The buddleia is mainly attacked by leaf bugs; the pests, which are up to 10mm in size, are difficult to see due to their leaf-green color, but they can damage the plant. If the bedbugs cannot be destroyed by their natural predators such as caterpillar flies and birds, the lilac should be treated additionally with a natural pesticide:
- Soap suds help against pests
- apply to the affected areas
- If the treatment does not show the desired result, use neem oil
- It is best to repeat the treatment in the early morning hours and, if necessary, after a week
In addition to infestation with leaf bugs, there is a risk that the lilac will be attacked by certain viruses that cause narrow-leaved leaves. The infestation can be recognized by the curled leaves, which show yellow mosaic spots. Once the plant is affected by this disease, unfortunately, any help comes too late – the lilac has to be destroyed.
Grooming and cutting
The buddleia does not require any special care; the right location, regular watering, targeted fertilization and optimal frost protection for young plants are sufficient for the plant to feel comfortable. However, it has been shown that the lilacs live longer and bloom more splendidly and regularly if the plant is pruned for care. The reason lies in the increasing baldness of the lilac from the underside of the shrub. As a result, unsightly broom growth forms. To care for the butterfly lilac, two different cuts are necessary: the winter cut and the summer cut.
- serves to rejuvenate the plant
- optimal time between November and March
- Only cut on frost-free days
- however, it shouldn’t be too sunny
- cut back all branches
- Cut previous year’s branches 5 centimeters into the old wood
- Radical pruning of the entire shrub is also possible
- Remove all old wood from older plants; only young shoots remain
While the winter pruning is mainly used to rejuvenate the lilac, the pruning in summer is primarily used for flower formation. This cut can be done in different ways. One possibility is to shorten all young shoots by around half. The best time to do this is in May or June. With this procedure it is achieved that the bloom arrives later – but at the same time also lasts longer. The lilacs can bloom well into October. The second option for performing a summer pruning is to prune back at a time when flowering has already started. The months of June or July are usually chosen for this. Wilted panicles can now be systematically removed. However, with this approach you will achieve a second flowering period,
There are different aspects to consider when cutting. Thoroughness plays a special role. It should cut off all dead and diseased branches right at the base. Don’t be afraid of a radical cut! Many branches can be cut off. In order for the cut to achieve the best possible result, the use of sharp and clean cutting tools is essential. Depending on the height of the lilac, the branches can be cut back close to the ground. With a very deep cut, the plant will not grow as profusely and will retain the abundance of flowers. Is the density of the crown more important than the size of the flowers? Then the cutting heights should vary; the shoots are separated off at different heights. As a rule of thumb, the less eyes are left, the thicker the lilac will be.
Special case – alternate-leaved buddleia
- can be recognized by the overhanging, arched growth
- ideally do not cut this lilac at all
- If pruning is necessary, the flower will be dropped
- The pruning of this species consists in thinning out the plant
- Cut out older shoots directly at the roots
Propagation and rearing
The propagation and rearing of the summer lilac is easy. For this you need annual shoots of the plant, of which you use the 15cm long tip. The flowers and the bottom leaf are removed before planting, ideally with a plant clipper. The formation of roots is made much easier if the remaining leaves are also shortened by about half. The substrate is also important for the optimal rooting of the plant. A special powder is available for this, which can be purchased in garden shops.
Then the planting takes place:
- Pour the sand-peat mixture into the flower pot
- stick the prepared twigs into it
- After pouring, put a glass hood over the cutting
- optimal rearing warmth is created
- Regular ventilation prevents mold growth
- Water the cuttings regularly and protect them from direct sunlight
- then the rooting can be completed by autumn
- now put plants in the garden soil
- Protect the soil from frost with brushwood and leaves for the first three years
Historical background of the lilac
Even if the summer lilac populates Germany’s gardens as a matter of course today – the popular plant was not always at home here. First the common lilac was introduced, which is originally native to the Orient. According to records, the ambassador Ogier Ghislain de Busbècq brought the lilac to the west in the 16th century. The colorful shrub soon enjoyed great popularity here. The butterfly lilac in particular was imported from China about a hundred years ago and bred in Europe. The fragrant plant quickly gained popularity not only in gardens; After the Second World War, the robust lilac was able to hold its own among the rubble.
Buddleia – use
The summer lilac can be used in many ways in the garden. As a decorative single shrub in the outskirts of the green area, the plant is just as well cared for as it is between perennial beds and arranged in groups. The combination of several plants in different colors looks particularly pretty. Properly cut and optimally put together, the plant then looks like a single, colorful shrub. But the butterfly lilac is not only suitable for planting in beds. You can also put the lilac in planters. The plant is then kept in a cool room to overwinter. The summer lilac can also be used effectively in roof gardens. Because the plant is not poisonous, it is also popular to plant in the vicinity of kindergartens and schools.
The butterfly lilac is a very easy to care for and robust plant, which impresses with its magnificent colors and its delicate floral scent. It is easy to grow in suitable soils, so that the plant can develop into a colorful shrub within a short time. Optimally cut and fertilized every now and then, the butterfly lilac can reach a lifespan of more than ten years. Whether you are an experienced hobby gardener or a layperson – the decorative plant is suitable for all plant lovers.