Purple top (Verbena bonariensis)
Purple top (Verbena bonariensis) is a perennial plant that can grow 1.5m – 3m tall and 10cm – 50cm wide. In this growing guide we’ll learn the cultivation details and how to plant Purple top (Verbena bonariensis).
This plant has several common names including: purple top, Argentinian vervain, South American vervain or tall verbena.
This is a deciduous plant that takes 2-5 years to reach full maturity.
In this article
Common name: purple top, Argentinian vervain, South American vervain, tall verbena
Scientific name: Verbena bonariensis
Plant type: Perennials
Habit: Columnar / Upright
Height: 1.5m – 3m
Spread: 10cm – 50cm
Sunlight: Full Sun
Soil: Chalk, Clay, Loam, Sand
Moisture: Moist but well drained, Well drained
Garden type: City & Courtyard Gardens, Coastal, Informal Garden, Rock & Gravel Garden, Wildflower meadow
Planting type: Flower borders and bedding, Wall-side Borders
Other characteristics: Plants for pollinators, RHS Award of Garden Merit
Perennial plants are one of the largest groups of plants.
They offer color, shape, fragrance and seasonal textures. The variety is such that there are plants to suit all sizes and styles of garden.
Traditionally, perennials are grown in borders, using a wall or hedge as a backdrop to bring out all their splendor during summer.
But since most gardens are not large enough for long borders dedicated exclusively to perennials, they are usually planted in mixed borders and beds, along with shrubs, annuals, biennials, and bulbs that extend the season of interest.
How to plant
In this section we will learn how to plant Purple top (Verbena bonariensis), know its needs in terms of soil, watering and sun exposure.
Purple top (Verbena bonariensis) is a plant that adapts to all types of soils, chalk, clay, loam or sand.
The chalky soil is pale and contains chunks of calcium-rich rock. It is a fertile and well-draining soil, almost always alkaline.
Clay soil is composed of more than 25 percent clay particles. These particles have a high moisture holding capacity and the soil is heavy to dig and can be waterlogged in winter (dry in summer).
The loam soil is dark, rich in organic matter but balanced in minerals. It offers the best of all worlds, retaining enough water for the plants, but allowing excess moisture to drain away. This is the most desired type of garden soil, perfect for most plants.
Sandy soil is light, porous and very easy to drain. It is a soil poor in organic matter and nutrients. It is composed of relatively large mineral particles that allow water to drain quickly.
It is not very sensitive to soil acidity or alkalinity and grows well in soils with pH acid, alkaline or neutral.
Regarding drainage, Verbena bonariensis likes to grow in moist but well drained or well drained soils.
Purple top (Verbena bonariensis) should be grown in full sun places.