Verbena

The key to success is patience during spring weeding.

1. The mother plant often dies after winter (you can tell because it does not sprout from the bottom part even in May).
2. However, dozens of small plants germinate from seeds around it.
3. Caution: Small verbenas look like nettles with dark, rough leaves. Do not hoe the bed too early so as not to destroy the new generation of plants. You can then transplant these seedlings where you need them.

Verbena bonariensis is a relatively healthy plant, but it can be troubled by:

• Powdery mildew (white mould): Appears as a white coating on leaves, especially in late summer if plants are too dense and lack air. Prevention involves sufficient spacing during planting.
• Aphids: Can appear on young shoots. Natural predators usually deal with them, or it is enough to shower the plant with water or use an oil spray.

Do not rush with planting Verbena bonariensis seedlings. Since this plant is sensitive to frost, plant it in its permanent site only in the second half of May, ideally after the so-called "Ice Saints".

If you purchase seedlings earlier, keep them in a bright and cooler place (e.g., in a greenhouse, on a glazed balcony) and protect them from night frosts.

Despite its height (it can grow up to 120–150 cm), Verbena bonariensis has surprisingly strong and stiff square stems that do not break easily in the wind.

• In a flower bed: It usually does not need support if it is planted among other perennials against which it can "lean".
• In a windy place: If it stands alone in a very windy site, it may be appropriate to stick an inconspicuous bamboo stick next to it or tie it with string.

Verbena bonariensis is not considered a highly toxic plant, but it is not edible.

• Ingesting parts of the plant can lead to stomach irritation and vomiting in dogs or cats.
• Furthermore, the stems and leaves are rough and hairy, which can irritate the skin of sensitive individuals or the mucous membranes of animals.
• We recommend growing it out of the direct reach of toddlers and puppies who like to taste everything.

An excellent trick for growing seedlings is so-called pinching.

• After planting (or when the seedling is approx. 15-20 cm), cut off the main tip shoot.
• This encourages the plant to form side shoots.

The result will be a lower, more stable, and much bushier shrub with a larger number of flowers, instead of one long "lanky" stem.

It is not necessary and sometimes it can even be detrimental.

• If you have ordinary garden soil, just add a little compost to the hole when planting.
• Excessive nitrogen fertilization leads to lush leaf growth at the expense of flowers, and stems can then break and flop over.
• If you are growing verbena in a container, fertilize mildly with a fertilizer for flowering plants once every 14 days.

Yes, and very intensely! Verbena bonariensis is one of the greatest magnets for butterflies, bees, and bumblebees. Its tiny purple flowers are full of nectar. If you want to enliven your garden with the movement of wings, this is one of the best choices.

Do not prune verbena in the autumn.

1. Dried stems and flower heads look beautiful in winter, especially when covered with frost.
2. Seeds ripen in the flowers, which serve as food for birds while also ensuring self-seeding for the following year.
3. Prune the old stems only early in the spring (March/April) just above the ground to make room for new shoots.

Adjust watering to the age of the plant:

• Freshly after planting: Water regularly until the plant roots well (approx. the first 2–3 weeks). Do not let the root ball dry out completely.
• Adult plant: Once rooted, Verbena bonariensis is very resistant to drought. Water it only during periods of prolonged heat. Waterlogging harms it more than drought.

Yes, you can also plant seedlings in containers.

• Container size: Choose a sufficiently large pot (at least 5–10 liters per plant) so that it has room for the roots and the substrate does not dry out too quickly.
• Care: In a container, it will require more frequent watering than in the ground.
• Tip: It looks great in pots as a central, tall element, underplanted with lower-growing annuals (e.g., trailing petunias or fan flowers).

Verbena bonariensis is a so-called "see-through" plant that adds airiness to flower beds. It looks great in combination with:

• Ornamental grasses: E.g., Stipa (feather grass), Miscanthus, or Pennisetum.
• Perennials: Coneflowers (Echinacea), rudbeckias (Rudbeckia), yarrow (Achillea), or sage.
• Roses: Its purple colour beautifully complements pink and yellow English roses.
• In groups: It stands out best when you plant 3–5 seedlings together.

Because seedlings often come from greenhouse conditions, it is necessary to harden them off before planting:

1. Roughly a week before planting, take the plants outside into semi-shade during the day.
2. Gradually increase the duration of the stay and the intensity of the sun.
3. Hide them inside for the night initially if low temperatures threaten.

This process prevents cold shock and burning of the leaves by the sun.

This verbena is a child of the sun. For rich flowering and sturdy stems, it requires:

• Full sun: Choose the sunniest place in the garden for it, ideally facing south.
• Permeable soil: It does not tolerate waterlogging. The soil must be well-drained, rather drier to slightly moist. In clay soil, it is at risk of root rot.

Beware of confusion!

• NO: Verbena bonariensis (Purpletop vervain) is an ornamental plant. It is not intended for consumption and does not have that typical lemon taste.
• YES: Aloysia citrodora (Lemon verbena) or Verbena officinalis (Common vervain) is used for tea.

Grow this ornamental verbena only for visual pleasure.

In our conditions, Verbena bonariensis is on the borderline of frost hardiness. It is often grown as an annual, but in mild winters (and in warmer regions of the Czech Republic) it can overwinter as a short-lived perennial.

How to increase the chance of survival:

• Do not cut the plant in the autumn (hollow stems would lead water to the roots, where it would freeze).
• Pile a layer of dry leaves or brushwood at the base of the plant.
• Even if the mother plant freezes, new plants often appear in the spring from self-seeding.