Alcea rosea nigra BLACK HOLLYHOCK (10 seeds)

Black Hollyhock, also known by its Latin name Alcea rosea nigra, is a very hardy biennial plant native to Southwest China. It reaches a height of 1.5 to 2 meters and belongs to the Malvaceae family.

The black flowers of the Alcea nigra are single-petaled and measure 5 to 10 cm in diameter. They are highly decorative in gardens, especially when planted against a light-colored wall. These spectacular flowers bloom from July until the beginning of September. While they are odorless, they attract many pollinating insects.

The whorl-shaped fruits appear at the end of the summer season. Each contains approximately 20 to 30 seeds.

Black hollyhock seeds are dark brown, circular, flat, and measure an average of 5 millimeters in diameter, weighing only a few decigrams.

Its foliage is deciduous, thick, and green, with lobed leaves arranged alternately.

- Uses:

Alcea rosea nigra is primarily cultivated for its exceptional ornamental appeal. Its flowers, of a purple so deep they appear black, bring a dramatic and vertical touch to cottage gardens and flower beds. Its imposing stature and prolonged summer flowering make it an essential plant for structuring outdoor spaces while attracting pollinators such as bees and bumblebees.

Beyond aesthetics, this variety has been historically used for its natural dyeing properties. The petals, rich in anthocyanins, are harvested to produce pigments ranging from dark purple to black, used to color textiles, inks, or to naturally tint certain beverages and confections. It is a sought-after plant-based alternative for artisans keen on using non-synthetic and biodegradable dyes.

- Cultivation and Sowing:

• The sowing period for Alcea rosea nigra should take place during the winter season.
• Start by stratifying the seeds naturally by leaving them outside during winter, or artificially by placing them in the refrigerator for 2 to 4 weeks before planting.
• Bury them in a tray of fine potting soil at a depth of 2 to 3 millimeters.
• Gently water the substrate using a spray bottle.
• Place the culture in a greenhouse in a warm, humid spot with a temperature between 20°C and 25°C.
• Germination typically begins 2 to 3 weeks after sowing.

- Soil and Substrate:

For container gardening, ensure good drainage at the bottom with gravel, small stones, or clay pebbles. It requires an airy, well-draining substrate rich in humus and organic matter.

- Humidity and Watering:

This plant requires a lot of water during its growth phase and especially during flowering. However, never drown the plant, as root rot is a frequent risk. One watering per week is recommended for plants in the ground, and every 3 days for those in pots. Mulching at the base of the plant will help reduce the frequency of watering.

- Light and Exposure:

The dark-flowered hollyhock must be exposed to full sun to bloom abundantly. For indoor cultivation under artificial light, horticultural LEDs or MH (Metal Halide) bulbs are preferred.

- Temperature and Hardiness:

This hardy plant grows well in temperatures ranging from 10°C to 25°C. It is very robust and can easily withstand extreme freezing temperatures as low as -18°C. Its USDA hardiness zone is 2-9.

- Propagation:

The only way to reproduce this tall, beautiful plant is through sowing; unfortunately, it cannot be grown from cuttings.

- Pests and Diseases:

It is sometimes infested by caterpillars that devour the leaves, leading to severe defoliation. The foliage is also frequently attacked by rust; in this case, a treatment with Bordeaux mixture (copper sulfate and lime) is necessary.