Yellow cosmos (Cosmos sulphureus)

Yellow cosmos (Cosmos sulphureus) is a plant in the annuals and biennials category that can grow 10cm – 50cm tall and 10cm – 50cm wide. In this growing guide we’ll learn the cultivation details and how to plant Yellow cosmos (Cosmos sulphureus).

This plant is commonly known as yellow cosmos.

This is a deciduous plant that takes 1 year to reach full maturity.

Plant profile

Common name: yellow cosmos
Scientific name: Cosmos sulphureus
Plant type: Annual / Biennial
Habit: Bushy
Height: 10cm – 50cm
Spread: 10cm – 50cm
Foliage: Deciduous
Sunlight: Full Sun
Soil: Chalk, Loam, Sand
Moisture: Moist but well drained
Garden type: City & Courtyard Gardens, Informal Garden, Sub-tropical
Planting type: Cut Flowers, Flower borders and bedding
Other characteristics: Plants for pollinators

Seasonal colors

How to plant Yellow cosmos (Cosmos sulphureus) – Alejandro Bayer Tamayo from Armenia, Colombia, CC BY-SA 2.0, via Wikimedia Commons

Annuals and biennials are ideal for formal or informal flower beds, but also for growing in pots and containers of all kinds. They are important plants for their rapid growth, instant color and relatively low cost.

They are also useful plants for filling spaces between newly planted trees and shrubs, as well as in perennial beds that may need to be revived after the first spring bloom.

They are an important ingredient in country house gardens and wildflower meadows.

How to plant

In this section we will learn how to plant Yellow cosmos (Cosmos sulphureus), know its needs in terms of soil, watering and sun exposure.

Soil

Yellow cosmos (Cosmos sulphureus) is not a demanding plant regarding the type of soil and can grow in chalk, 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.

• 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, Cosmos sulphureus likes to grow in moist but well drained soil.

Sunlight

Yellow cosmos (Cosmos sulphureus) should be grown in full sun places.

Cultivation profiles – Growing Yellow cosmos (Cosmos sulphureus) – Salicyna, CC BY-SA 4.0, via Wikimedia Commons