Sunglossy

Class

Dicotyledons

Division

Angiospermae

Family

Asteraceae or Compositae

Order

Asterales

Genus

Helianthus

Species

annuus

Description

An annual ornamental herbaceous plant also known as sunflower, it is extremely versatile, capable of embellishing green spaces such as flowerbeds or borders as well as terraces and balconies in planters or tubs with its characteristic inflorescences bearing petals in warm, bright colours gathered around the typical discoidal receptacle, often chocolate-coloured, present from spring until the end of summer or early autumn depending on the variety, and also welcome useful insects such as bees or butterflies, and some birds are also fond of its oil-rich fruits called achenes.

It is easy to cultivate and tolerates even hot summer climates if watered regularly. It is also suitable both as a single specimen in pots and to create homogeneous monochrome masses as well as for mixed compositions with other ornamentals or in association with horticultural species such as cucumbers, peppers and tomatoes.

Species video

https://youtu.be/Fd5nOrC-qHQ

Variety description

A medium-sized plant with very showy flowers and bright, silky green foliage.

Curiosities and special features

The name Helianthus derives from the Greek helios and anthos, meaning 'flower of the sun', referring to heliotropism, i.e. the plant's tendency to orient its inflorescence in the direction of the sun; the specific epithet, annuus, emphasises the length of the plant's vegetative cycle.

Local populations in the species' areas of origin ground the seeds to obtain a flour for the preparation of baked goods such as bread and cakes or to extract a purplish-grey dye; they also used an infusion obtained from the flowers for medicinal purposes.

The inflorescences can be used for cut flower arrangements, taking care to place them immediately in fresh water.

Origin and distribution

Belonging, like Jerusalem artichoke, to the genus Helianthus, it is a species native to the northern United States, Canada and northern Mexico where it was a primary source of food for the local populations. It arrived in Europe at the end of the 1500s where it was immediately appreciated as a plant for both ornamental and productive use. From the 1800s to the present day, a series of hybridisations have taken place, leading to many cultivars of different heights, expanding the colour range of the flowers and ensuring greater plant compactness.

Flower size

Medium-sized flower compared to other varieties of the same species.

Leaf

The leaf has a rounded lamina, silky to the touch.

Fruit

Seeds contain no seeds and the skin is inedible.

Flowering period

The spectacular inflorescences provide an accent of colour and light from early spring to summer for a duration of 90 to 120 days.

Inflorescence

Inflorescence corymb

Leaf colour

Solid colours.

Plant height

The height of the plant varies from 0.3 to 0.7 m, visually enhanced by the showy inflorescences that stand erect among the foliage.

Lifespan

Seasonal plant.

Where to plant

Mainly used to add colour and vibrancy to balconies, borders

Stem

The stem is herbaceous, cylindrical and robust; the variety has no thorns.

Flower

The flower is medium-sized with single-coloured petals. It is arranged in large corymbal inflorescences. It flowers from early spring to summer, with a flowering period of between 90 and 120 days. It is not particularly attractive to pollinating insects.

Growth

It presents compact growth.

Plant habit

It displays the characteristic upright bearing that gives it a primary role in mixed compositions, making it an attractive focal point.

Branching

It naturally has little branching.

PH

It prefers a soil or substrate pH ranging from sub-acidic to neutral, between 6.0 and 7.5.

Soil preparation

Before transplanting in spring, carry out superficial digging, removing any weeds, bulky stones and residues of previous crops, then bury organic or chemical slow-release fertiliser, which will provide the nutrients necessary for the first phase of development following planting. Continue by breaking up the most compact and coarse clods with a hoe, then carefully level the surface by preparing the planting holes according to a suitable density.

Sun exposure

It prefers a full sun exposure; for best flowering performance expose it to maximum light while considering an adequate water supply, especially on the hottest and driest summer days.

Ideal climate and temperature

The ideal temperature is between 15 and 25 °C. However, it is a plant that shows good climatic adaptability, tolerating even warm climates. The biological temperature is between 5 and 40 °C.

Use

Known to all as sunflower, for its warm and bright flowers representative of the summer period, it is widely used in:

Ornamental

Hardiness

A variety with medium hardiness, which gives it added value, particularly appreciated by growers and green enthusiasts at all levels of experience.

Soil

The ideal soil for proper sunflower development is medium-textured, peaty, fertile and well-draining; for use in pots and planters, a substrate for spring plants based on fibrous peat and perlite is recommended.

Difficulty

Cultivation is extremely easy, the management effort required for proper vegetative development is low overall.

Growing tips

The following measures and cultivation aspects are recommended in order to achieve the best growth vigour:

Always keep the substrate moist Prefers warm and humid climate

Combinations with other plants

The sunflower is the ideal solution not only for creating bright, compact and monochrome groups, but also for mixed compositions in harmonious patterns with other ornamental species such as Anthemis tinctoria, Celosia, Cineraria maritima, Coleus, Coreopsis, Gaura, Zinnia elegans .

Planting

As with any ornamental bedding species, planting should be carried out at a suitable density to ensure the expression of the best vigour in growth, thus obtaining proportionate and visually harmonious final effects; an average planting density of 8 plants per square metre is therefore recommended. When transplanting ensure that the root ball is wet and position the seedling by burying it up to the first cotyledonary leaf stage and irrigate immediately afterwards.

Propagation

Reproduction/Propagation is by sowing.

Watering

Plant with medium to high water requirements. The use of rainwater is recommended, alternatively of aqueduct water, by hand watering or irrigation system. During the transplanting phase, avoid desiccation and drying out, which can lead to stress for the young plant and compromise subsequent growth. Afterwards, always keep the soil or substrate moist, avoiding both water stagnation, which can cause the development of fungal diseases and subsequent root rot with plant death, and dryness with consequent leaf yellowing. For eventual sowing, it is advisable to keep the soil wet until the sprout emerges, after having completely buried the seed.

Fertilising

Before transplanting, carry out a background fertilisation by burying organic or slow-release chemical fertiliser. During the spring-summer period, following proper post-transplant settling, apply a balanced liquid fertiliser specific for ornamental plants to the substrate or soil, to be diluted in the irrigation water according to the appropriate doses and frequencies as indicated on the relevant information label.

Pet safety

Ingestion toxicity for pets not known, consider the specific case and consult with your veterinarian before administration.

Edibility for humans

In some varieties the achenes, i.e. the fruits that are often called seeds, are edible when dried. Ornamental varieties are not edible.

Toxicity for humans

Ingestion toxicity not known. Consider variety.

Tip

The plant needs plenty of water to prevent the leaves from turning yellow, and maximum exposure to the sun. It should be fertilised regularly.