Origin and Distribution
Verbenas belong to the verbena family (Verbenaceae) and are therefore often referred to as "verbena". The genus is originally native to the warm regions of South America, but some species also have their origin in other parts of the world. The European wild species Verbena officinalis (verbena) has been considered a medicinal plant since ancient times and was preferred for childbirth and injuries. Most of the verbenas commercially available today are hybrid forms and are characterized by a wide range of flowers. In addition, some solid-seeded species - such as the Patagonian verbena (Verbena bonariensis) - are also very popular as short-lived garden and potted plants.
- Hardy or sensitive to frost - the verbena
- The most proven way to propagate a verbena
- Simple or time consuming - the maintenance of the verbena
Verbenas are primarily used to plant balcony boxes, (€ 106.25 at Amazon *) pots and hanging baskets, a distinction being made between compact and hanging varieties. Compact and rather flat versions such as 'Vepita', 'Vectura' or 'Lindolena' come into their own in boxes and small vessels, while shapes with long and strong shoots unfold their splendor best in hanging baskets. Verbenas look particularly pretty in combination with other lavishly blooming balcony classics such as vanilla flowers (Heliotropium arborescens), magic bells (Calibrachoa), petunias (Petunia) or begonias (Begonia).
Verbenas are also very suitable for underplanting, for example rose or hibiscus tall trunks. Furthermore, the flowers cut a good figure in any mixed summer flower and perennial bed, especially in combination with roses, as a gap filler or as a border planting. For example, a circular, colorfully planted flowerbed in the middle of a lawn appears apart.
Appearance and stature
We usually cultivate the frost-sensitive and warmth-loving verbenas as an annual, although some species and varieties can be overwintered. However, the effort is not worth it, as the flowers produce numerous seeds in autumn. These can easily be used for further propagation.
The flowers grow herbaceous, very delicate and slender and reach different heights depending on the species and variety. The classic hybrid varieties bred for pot culture are usually between 15 and 30 centimeters high. Some variants grow upright, others creep or with drooping shoots.
The pleasantly fragrant verbenas are very popular forage plants with butterflies and other insects.
The lobed or pinnately fissured, cross-opposed leaves of the verbena have a toothed edge. Some varieties have rough, hairy foliage, others smooth. The square stem is characteristic of the genus. As a rule, stipules are not developed.
Blossoms and flowering period
However, the delicate, green leaves of the verbena take a back seat to their lush, multi-flowered umbels. The umbrella-like to spherical inflorescences bloom in almost all colors from white to yellow, pink, red, purple to green and brown. However, the striped or two- to multi-colored varieties such as 'Voodoo Star', 'Lanai Twister' or 'Wicked' are particularly attractive. Verbenas also delight with their very long flowering time, which extends from May until well into autumn. Usually only the first frost puts an end to the abundance of flowers.
The flowers are pollinated by insects. Then numerous nuts form that contain the seeds. You can collect these and use them again and again for re-sowing. Some types of verbena - especially the frost-hard ones such as Verbena officinalis or Verbena hastata - like to sow themselves in the bed. These verbenas are cold germers and need a cool weather period in the cold season before germinating in spring when the temperature rises.
Verbenas have been used as a medicinal herb for centuries, primarily for external applications such as inflammation or poorly healing wounds. Even today you can still buy verbena tea and oil in drugstores and pharmacies, whereby these natural remedies are made from the herb of the common verbena or verbena officinalis (verbena officinalis). However, the hybrid forms available in nurseries are purely ornamental plants and are not suitable for medicinal purposes.
In principle, verbenas - regardless of the type and variety - are not poisonous, the herb can even be eaten and the flowers can be used as a decoration for summer salads and desserts. But be careful: As with so much, the dose makes the poison. The pretty flowers contain verbenaline, a glycoside that is harmful only in large doses, which is why you should only enjoy the slightly bitter-tasting plant parts to a limited extent.
Which location is suitable?
Plant the verbenas in a sunny and warm location as possible, then they will bloom particularly profusely and for a long time. A south-facing location is ideal, especially on the balcony and terrace. Rain and wind do not bother at least the newer hybrid breeds, even hot locations are tolerated well. This sun-loving flower is only unsuitable for shady places and therefore forms little or no flowers in places that are too dark.
In terms of the optimal soil quality, however, verbenas are not particularly demanding. The flowers feel most comfortable in humus-rich and nutrient-rich, fresh to moist, but well-drained and at best slightly acidic soil. A high-quality compost-based potting soil is sufficient for balcony and other tub plantings.
Verbenas are ideally suited for a pot culture, after all, many of the newer hybrid varieties have been specially bred for keeping on balconies and terraces. Make sure the pot is well drained - clay granules or perlite in the substrate and a drainage hole on the bottom of the pot ensure that - and the regular supply of water and fertilizer. Verbenas bloom particularly profusely in warm and sunny locations, which is why a south-facing balcony is ideal for these flowers.
You don't have to buy the pretty verbenas every year, you can propagate them again and again from the seeds yourself. For the summer flowering, you prefer the flowers from February, whereby you first have to break the sprout inhibition - verbenas are cold germers and must therefore be kept in the refrigerator for a period of about four weeks. And this is how you pull the small plants out of the seeds:
- Spread the seeds out on a slightly damp surface (e.g. conventional kitchen paper)
- Roll up the mat and put it in the refrigerator for about four weeks
- Always keep the paper and seeds slightly moist
- Seeds must be kept cool, but must not be exposed to temperatures below 0 ° C
- Now plant the seeds or seedlings in small pots or in a bowl with a growing medium. (€ 9.05 at Amazon *)
- Now grow the seedlings at cool temperatures between 10 and 15 ° C, until they can finally be planted out from mid to late May and used to rising temperatures.
It is easier if you sow the seeds in a cold frame in autumn and prefer them there. However, make sure the moisture remains constant and prick out the young plants in good time.
Plant verbenas correctly
Always place the verbena in excavated soil enriched with ripe compost, while potted plants are placed in fresh potting soil. Mix these with clay granules and lay a drainage layer made of expanded clay on the bottom of the pot (€ 17.50 on Amazon *). After planting, the root area should be mulched - for example with a mixture of bark mulch and compost - to keep the moisture in the soil longer and to prevent the flowers from drying out.
What is the best time to plant?
Basically, plant verbenas throughout the season, but you should not put the mostly sensitive flowers outside until the end of May. Many species and varieties are very sensitive to frost and should therefore not be exposed to any late frost.
The correct planting distance
Depending on the species and habit, verbenas need a planting distance of between 25 and 50 centimeters. The permanent bloomers are best planted in dense tuffs, where they soon develop dense carpets of flowers.
The permanent flowering verbena has a high water requirement, so the soil should never dry out completely. Regular watering is therefore useful for potted flowers and during warm and dry phases even for planted specimens. At the same time, however, the plant does not tolerate waterlogging, so that the soil should only be moderately moist, but never dripping wet. Verbenas in the bed are also mulched with bark, lawn clippings and / or compost so that the soil does not dry out on hot days.
Fertilize verbena properly
Verbenas are not only downright thirsty, they also have high nutritional requirements. From April onwards, provide specimens cultivated in planters with a liquid fertilizer for flowering plants once a week, while flowers that have been planted receive organic compost fertilization once a month or, alternatively, are also supplied with commercially available flowering plant fertilizers. When planting, it also makes sense to enrich the excavation with compost and horn shavings or horse manure.
Properly cut verbs
Since verbenas are usually grown annually, pruning is not necessary. Only the faded flower umbels should be cleaned regularly in order to stimulate the plant to develop new flower balls again and again.
Verbenas can be propagated using seeds that you have collected or bought, although this process is a bit laborious because of the cold stimulus required. The propagation of cuttings is not uncomplicated either, after all, the head cuttings cut in August must be overwintered in a cool, but light and frost-free environment. Do not plant the vegetatively propagated verbena in planters or in the bed until next spring.
Some types of verbena are annual anyway and die off after the seeds ripen. Others, on the other hand, are generally perennial, but must be wintered frost-free and light - only a few verbenas, such as the native verbena, are frost-hardy and can also stay outside over the winter. The abundant flowering hybrid varieties usually available in specialist garden centers, on the other hand, need a lot of warmth and must not be cultivated below 0 ° C. Hibernation of these is often not worthwhile, as plants that are over the years are often quite lazy to flower. It is better to just cut cuttings and overwinter them.
Diseases and pests
Since verbenas prefer warm locations, they often have to fight with spider mites (also: red spider), whiteflies or aphids, especially when it is too dry. Here it helps to keep the flowers evenly moist and, if necessary, spray them occasionally with a fine atomizer. Planted specimens must be protected from snails, for example by a barrier, mulching with sawdust or straw or the application of snail pellets. Furthermore, socialization with plants that are in turn not particularly liked by snails, such as carnations, geraniums, phlox, poppies, asters or begonias, helps.
Some varieties of verbena are also quite susceptible to powdery mildew, which often occurs in warm and sunny locations. However, many of the newer breeds have already been bred for resistance. Yellow leaves, on the other hand, are often an indication of a nutrient deficiency, which occurs primarily on calcareous soils and which you can eliminate with an iron fertilizer.
Verbenas don't bloom, what to do?
If verbenas do not want to bloom, they are either too dark or they are not sufficiently fertilized. The continuous bloom between May and October costs the plant a lot of strength, which is why it has a high demand for water and nutrients. In particular, potted plants must be continuously supplied with a good, balanced flowering plant fertilizer from April and throughout the entire growing season.
The tall varieties in particular are ideal as cut flowers for the vase. They can even be dried and used for beautiful dry bouquets. It is best to cut verbenas intended as cut flowers when the buds have not yet fully opened. Put the vase with the flowers in a bright light and change the water every day, then you can enjoy the splendor all the longer.
Species and varieties
There are thousands of different varieties of verbena, the flowers and growth forms of which are very different. The color spectrum is huge, although there are also many two- and multi-colored variants. The flowers can also be single or double, with a jagged or ruffled edge or without.
Under no circumstances should you confuse the popular balcony and bed flower with the lemon verbena or verveine (Aloysia citrodora), which is also known as the lemon bush. Although this species also belongs to the verbena plant family, it is not an iron herb. In contrast to these, lemon verbena contains an essential oil that tastes intensely of lemon and is therefore often used for teas and perfumes.
The most beautiful verbenas for balconies and beds:
- 'Scarlet': scarlet flower, pendent shoots
- 'Starfight': two-tone, pink flowers with a white border, hanging shoots
- 'Tapien': purple flowers, hanging shoots
- 'Peaches & Cream': peach-colored flowers with a gradient
- 'Lila Luzi': two-colored, blue flowers with a star-shaped white center, compact growth
- 'Bright Rose': pink flower
Also very attractive is the so-called lance verbena (Verbena hastata) with its brightly colored flower candles in red or purple. These varieties reach heights of around 100 to 120 centimeters. With a height of up to 150 centimeters, the Patagonian verbena (Verbena bonariensis) is also very tall. The species forms large, blue to blue-violet flower balls.