Overview
Draba spectabilis Greene var. spectabilis is a species of flowering plant within the mustard family Brassicaceae. It is commonly referred to as giant rockcress or showy draba. This plant is native to western North America, where it can be found growing in rocky areas, cliffs, and alpine meadows.Appearance
Giant rockcress is a perennial plant that grows to a height of 4 to 12 inches. It has basal rosettes of leaves that are green, linear or spatulate in shape, and covered in fine hairs. The flowers of giant rockcress are showy and fragrant, with four white petals that are arranged in a cross shape. The blooming period occurs from May to August, and the fruit is a silique or a long, narrow seed capsule.Uses
Giant rockcress is primarily used as a decorative plant. Its attractive flowers and small size make it a popular choice for rock gardens and alpine gardens. Additionally, it is used for erosion control and habitat restoration in disturbed areas. The plant is also edible and has been used by indigenous peoples as a food source. The leaves can be eaten raw or cooked, and the seeds can be ground into flour.Cultivation
Giant rockcress is a hardy plant that requires full sun to partial shade and well-drained soil. It prefers cool temperatures and can tolerate drought, but it requires regular watering during its growing season. This plant is relatively easy to cultivate and can be propagated by seed or division of the root mass. It is not commonly found in nurseries, but can be obtained from specialized native plant nurseries or obtained through seed exchanges.Growth Conditions for Draba spectabilis Greene var. spectabilis
Draba spectabilis Greene var. spectabilis is a small perennial herb that is indigenous to the western United States. The plant prefers habitats with well-draining soils, including ridges, rocky outcrops, and talus slopes in the alpine region that receives abundant light and moisture. Here are the typical growth conditions for Draba spectabilis Greene var. spectabilis:
Light
Draba spectabilis Greene var. spectabilis thrives well in full sun or partial shade. In its natural habitat, the plant grows well on ridges, rocky outcrops, tundra, and talus slopes that receive ample sunlight. In cultivation, the plant should be grown in a location that receives at least six hours of direct sunlight each day.
Temperature
Draba spectabilis Greene var. spectabilis is adapted to cold environments and can grow well in different temperature ranges. The plant can tolerate low temperatures of up to -20°C in winter, making it a suitable choice for gardens in regions with cold climates. The optimal temperature for Draba spectabilis Greene var. spectabilis growth ranges between 10°C and 25°C.
Soil Requirements
The ideal soil for Draba spectabilis Greene var. spectabilis growth is well-draining and sandy, with a neutral or slightly alkaline pH. The plant requires consistently moist soil during its growing season. When cultivating the plant, it is important to ensure the soil does not become waterlogged, as this can lead to root rot. The addition of organic matter to the soil, such as compost, can help improve soil texture and fertility.
Cultivation methods for Draba spectabilis Greene var. spectabilis
Draba spectabilis Greene var. spectabilis is a low-growing plant that requires well-draining soil. It thrives in regions that have cool summers and winters. This plant is ideal for rock gardens and alpine gardens where it can receive the full sun exposure it requires. When planting Draba spectabilis Greene var. spectabilis, ensure that it is placed in a location that has good air circulation to prevent diseases such as mildew.
Watering needs for Draba spectabilis Greene var. spectabilis
Draba spectabilis Greene var. spectabilis should be watered regularly but not excessively. It prefers soil that is slightly moist but not wet. This plant does not tolerate drought, especially during the summer months, so it's important to keep the soil moist. However, overwatering can lead to root rot, so it's essential to ensure that the soil drains well.
Fertilization needs for Draba spectabilis Greene var. spectabilis
Draba spectabilis Greene var. spectabilis is a low-maintenance plant that doesn't require heavy fertilization. Organic fertilizers such as compost or manure should be used sparingly to prevent over-fertilization which can lead to weak growth. A slow-release fertilizer that is high in potassium and low in nitrogen is ideal for this plant.
Pruning for Draba spectabilis Greene var. spectabilis
Pruning of Draba spectabilis Greene var. spectabilis is optional. This plant doesn't require constant pruning, but it's essential to remove any dead or diseased branches or leaves to prevent spread. Additionally, pruning can be done to shape the plant or control its size.
Propagation of Draba spectabilis Greene var. spectabilis
Draba spectabilis Greene var. spectabilis is propagated through both sexual and asexual means. Here are some of the common methods used for propagation:
Seed Propagation
The easiest and most common way to propagate Draba spectabilis Greene var. spectabilis is by seed. Collect the seeds when they are mature and dry, usually in late summer. The seeds should be sown immediately into a well-draining potting mix. Cover the seeds lightly with soil and water gently. Maintain consistent moisture and a temperature range of 15-20°C for optimum germination. Seeds should start to germinate within two to three weeks, and once they have developed two true leaves, they can be transplanted into individual containers or outdoors.
Division
Draba spectabilis Greene var. spectabilis can be propagated through division. This method is best done in early spring before new growth emerges. Dig up the clump and gently separate it into smaller sections. Each section should have both roots and shoots. Plant the sections into new containers or directly in the outdoor garden. Keep the new divisions evenly moist and give them adequate sunlight to promote growth.
Cuttings
It is also possible to propagate Draba spectabilis Greene var. spectabilis through stem cuttings. Take cuttings from new growth in spring or summer and place them in a well-draining potting mix. Rooting hormone can be applied to speed up the rooting process. Place the cuttings in a warm, bright area and keep the soil slightly moist. Roots should form within a few weeks, and the new plants can be transplanted to individual containers or outside in a garden bed.
Disease Management
Draba spectabilis Greene var. spectabilis is relatively resistant to most diseases that affect plants, but some commonly reported diseases to watch out for include:
- Clubroot: This is a fungal disease that attacks the roots of plants in the Brassicaceae family, causing stunted growth and yellowing of the leaves. To manage clubroot, it is recommended to maintain a pH level of 6.5 and above, practice crop rotation, and avoid planting in areas that had previous clubroot infections.
- Blackleg: This bacterial infection causes rotting stems and leaves to wilt and fall off. To control blackleg, it is recommended to destroy infected plants, avoid planting in infected soil, and apply appropriate fungicides.
- Downy Mildew: This is a fungal infection that causes yellow spots on the leaves, which eventually turn brown and fall off. To manage downy mildew, it is recommended to use resistant plants, practice crop rotation, and apply appropriate fungicides.
Pest Management
Draba spectabilis Greene var. spectabilis is also relatively resistant to most pests, but some common pests to watch out for include:
- Cabbage Aphids: These tiny insects suck sap from the leaves, causing them to curl and turn yellow. To manage cabbage aphids, it is recommended to use natural predators such as ladybugs and lacewings or spray insecticidal soap.
- Cabbage Maggots: These pests attack the roots of plants, stunting growth and causing wilting. To manage cabbage maggots, it is recommended to avoid planting in infested soil and use row covers to prevent egg-laying.
- Cabbage Loopers: These are green caterpillars that eat the leaves, causing skeletonization and stunted growth. To manage cabbage loopers, it is recommended to handpick them or use natural predators such as birds and wasps. Bacillus thuringiensis (Bt) is also an effective biological control method.
