Overview
Zilla spinosa (L.) Prantl subsp. spinosa, commonly referred to as Spiny Zilla, is a species of deciduous herbaceous plant that belongs to the family Apiaceae. It is native to Europe, Northern Africa, and Western Asia. The plant comprises several subspecies that differ in size, stem appearance, flower shape, and other features. In this article, we focus on the Spiny Zilla subsp. spinosa.Description
The Spiny Zilla is a shrub that can grow up to two meters tall. It has a woody stem with several branches that are covered with sharp, spiny leaves. The leaves are green, bipinnate, with up to seven pairs of pinnae, each of which has several pairs of leaflets. The leaflets are small, oblong, and serrated. The stem and the leaves contain essential oils and are fragrant when crushed. The Spiny Zilla produces small white or pinkish flowers that are arranged in umbels, which are umbrella-like clusters. The flowers bloom from June to August and are followed by small, oblong fruits that split into two halves, each containing a single seed.Common names
The Spiny Zilla is known by various names in different languages and regions. In English, it is commonly referred to as Spiny Zilla, Thorny Caraway, Thorny Cumin, or Thorny Fennel. In Italian, it is called Carvi spinoso, while in Spanish, it is known as Alcaravea espinosa.Uses
The Spiny Zilla has been traditionally used for various medicinal and culinary purposes. The essential oils obtained from the plant have antiseptic, carminative, and diuretic properties. They are used to flavor liqueurs, mouthwashes, and toothpaste. In traditional medicine, Spiny Zilla seeds and extracts have been used as a digestive aid, to relieve bloating and stomach cramps, and to increase milk production in breastfeeding mothers. The seeds are also used to make a tea that is believed to promote sweating and relieve symptoms of cold and flu. In the culinary world, Spiny Zilla seeds are used as a spice, particularly in European, Middle Eastern, and North African cuisines. The seeds have a slightly bitter, earthy flavor and are commonly used to flavor bread, cheese, and sausages. They are also used in the production of herbal liqueurs, such as Chartreuse and Kümmel.Light Conditions
Zilla spinosa (L.) Prantl subsp. spinosa, commonly known as the spiny zilla, requires full sunlight for optimal growth. It can tolerate some shade, but the plant may become leggy and fail to flower if grown in low light conditions.
Temperature Requirements
Spiny zilla prefers warm temperatures and thrives in zones 9-11. The optimum temperature range for growth is between 65°F to 85°F. The plant can tolerate a cooler temperature as low as 50°F during the winter months, but protection from frost is recommended.
Soil Requirements
The spiny zilla is a hardy plant that can grow in a variety of soils, but it will thrive in well-draining soils with a pH range between 6.0 to 7.5. Sandy loam or loamy soils are ideal, but the plant can also tolerate clay soils as long as they are well-draining. The addition of organic matter, such as compost or leaf mold, will improve the soil's moisture-retaining capacity and fertility, leading to optimal growth.
Cultivation
Zilla spinosa is fairly easy to cultivate, requiring minimal maintenance. It is suitable for both indoor and outdoor growth, but it requires a lot of sunlight to grow well. It prefers well-draining soil that is slightly acidic to neutral with a pH range of 5.5 to 7.0. The ideal temperatures for the plant growth are between 60°F (15.6°C) to 85°F (29.4°C).
Watering Needs
The plant needs to be watered regularly, especially during the growing season. The frequency of watering should be determined by the surrounding humidity, temperature, and exposure to sunlight. It is recommended to water the plant when the top inch of soil feels dry. Overwatering may lead to root rot, which can compromise the plant's growth and survival.
Fertilization
Zilla spinosa requires fertilization to grow and produce flowers successfully. It is recommended to fertilize the plant every three to four weeks during the growing season using a balanced fertilizer. The plant responds well to fertilizers with balanced nitrogen, phosphorus, and potassium ratios. Over-fertilizing the plant can cause damage to the roots and lead to stunted growth or leaf drop.
Pruning
Pruning is required to keep the plant in great shape and stimulate new growth. If the plant becomes too tall, it can be pruned to maintain manageable size. Pruning is recommended at the end of the growing season or early spring before new growth starts. The best practice is to use clean, sharp shears and cut close to the base of the branch or stem. Dead or diseased leaves and branches should be removed promptly to avoid the spread of infections.
Propagation of Zilla spinosa (L.) Prantl subsp. spinosa
Zilla spinosa (L.) Prantl subsp. spinosa can be propagated either by seeds or vegetatively by stem cuttings.
Propagation by seeds:
Seeds of Zilla spinosa (L.) Prantl subsp. spinosa can be collected once they turn brown, and sown in well-draining soil mixed with sand or perlite. The seeds can be sown directly in the ground or in containers. The containers should be placed in a warm and sunny location and should be kept moist until the seedlings appear.
Vegetative propagation by stem cuttings:
Zilla spinosa (L.) Prantl subsp. spinosa can also be propagated through stem cuttings collected from a healthy and mature plant. The cuttings should be taken in late spring or early summer when the plant is actively growing. The cuttings should be around 10-15 cm long and should have a few nodes. The lower leaves should be removed, and the cutting should be dipped in rooting hormone before being planted in well-draining soil mixed with sand or perlite. The planted cuttings should be misted regularly and kept in a warm and bright location until the roots develop.
Propagation by stem cuttings has a higher success rate than propagation by seeds, and the resulting plants will retain the traits of the parent plant.
Disease Management
Zilla spinosa is known to be susceptible to leaf spot diseases caused by fungi, including Phoma and Alternaria species. The symptoms include small dark or brown spots on the foliage that can spread, leading to defoliation and reduced plant growth. To manage these diseases, it is recommended to remove and destroy infected plant debris, practice crop rotation, and apply fungicides. Fungicides such as mancozeb, chlorothalonil, and copper fungicides are effective in controlling leaf spot diseases. However, it is crucial to follow the label directions and use them in a manner that minimizes environmental exposure and resistance development.
Pest Management
Several insects and mites can infest Zilla spinosa and cause severe damage. The most common ones are spider mites, aphids, and whiteflies. Spider mites cause leaves to become speckled and yellow, and webbing may appear on the plant's surface in severe cases. Aphids and whiteflies feed on the plant's sap, leading to yellowing and distortion of the leaves. They also produce honeydew that attracts ants and promotes the growth of sooty mold.
One way to manage these pests is to use insecticidal soap or neem oil. These are organic options that help control a wide range of pests without harming beneficial insects. Another approach is to use predatory insects such as ladybugs, lacewings, and predatory mites, which help control the pest population. Additionally, practicing good sanitation, including removing dead and damaged plant material, can significantly reduce the pest's population and prevent further infestations.
