Cleome hassleriana is an annual herbaceous plant that reaches 100-150 cm in height, native to South America; produces long erect stems, herbaceous, rigid, light green in color, covered with a thin down, which bear large compound leaves, carried by long petioles, consisting of 5-7 leaflets, dark green; on the inferior page they are covered by a thin hair and equipped with small thorns. From the beginning of summer until autumn, at the apex of the stems of Cleome hassleriana, small white, pink or purple flowers bloom, gathered in particular spherical or crown-shaped inflorescences. The flowers and leaves are intensely scented; the prolonged flowering makes these plants very suitable to be cultivated in the garden, as background plants for other annuals, or even in small groups.
Plants belonging to the species of Cleome hassleriana prefer sunny positions, but they also tolerate the positions placed in partial shade. Temperatures below 5-8 ° C lead to the drying out of the plants. For this reason, this kind of plant is cultivated as an annual, even though it can take on the characteristics of perennials, as it tends to self-seed and present new plants the following year.
As for the supply of water for the correct growth of this kind of annual plant, it is good to know that the specimens belonging to this annual variety can easily withstand periods of prolonged drought, do not fear the summer heat, and are generally satisfied rainy. For young specimens that need to grow, it may be appropriate to supply more water, especially in the presence of long dry periods.
To cultivate as best as possible this plant kind, it is best to place it in a soil rich enough in humus, soft, light and very well drained; It is good, in fact, that water does not form in the soil that could cause deleterious root rot for the health of the plant. They settle down in May, when the minimum temperatures are above 10 ° C and there is no risk of running into late frosts or in sudden drops in temperature that would be fatal for the growth of these plants.
The multiplication of this type of plants occurs by seed, after having left the seeds in water for about 24 hours; they are sown in March, in a protected seedbed, or directly in their home, in May. It often happens that this kind of plant is self-seeded, so that the following year new plants are born, born from the seeds left by the plants of the previous year, even if, for a sure result, it is good to proceed with manual sowing, which guarantees a greater degree of success.
Cleome hassleriana: Parasites and diseases
often aphids attack new shoots and flowers. For this reason it is advisable to take preventive action with broad-spectrum antiparasitic products that will protect the plants, or, in the presence of parasites, it is possible to use natural products, such as a nettle macerate to be sprayed on the affected specimens or a compound prepared with water and marseille soap, in the quantity of a teaspoon in a liter of water, which will help to effectively combat the spread of aphids.