Cytisus nigricans, the black broom, is a species of flowering plant in the subfamily Faboideae of the family Fabaceae. Growing 3–5 ft (0.91–1.52 m) tall, it is a slender deciduous shrub with erect branches. Masses of brilliant yellow, slightly fragrant pea-like flowers appear in long racemes on the current year's growth in summer and early autumn.The more compact cultivar 'Cyni', to 1 m (3.3 ft), has gained the Royal Horticultural Society's Award of Garden Merit. It is hardy but prefers a sheltered position in full sun, with poor soil. It is preferable to remove the mature seed pods in autumn.
Black broom has strong resistance to disease and is generally not susceptible to illnesses. As for care, this plant is fairly low-maintenance. When grown outdoors it needs only minimal watering, and larger plants usually do not require pruning. Smaller plants, however, should be pruned after they finish blooming. Black broomt is appropriate for anyone with outdoor space, such as a garden or deck, and does not need much gardening experience.
How to keep Lembotropis Nigricans.
Light
Black broom's strong growth and vigor depend on ample sunlight, reflecting the conditions of its native habitat. Every stage of its life cycle thrives in direct, unshaded sun. Insufficient sunlight can impair its growth, whereas too much sun causes little harm.
Water
Black broom thrives in a consistently moist environment and should be watered weekly to stay healthy. Although it can tolerate short periods of dryness, its water needs remain stable throughout the year, particularly when grown outdoors, as it is an evergreen plant.
Temperature
Black broom is highly adaptable to a variety of climates, from blazing summers to frigid winters. Nonetheless, it has a preferred temperature range for healthy growth. If temperatures rise too far, the plant can experience heat and humidity stress that may kill it. In locations where temperatures near the lower bound of its cold tolerance, providing insulation to protect the plant is necessary.
Fertilizer
Timing is vital when fertilizing Black broom. Start fertilizing in early spring and continue once a month until early summer. Fertilizer encourages attractive blooms and supplies energy during both dormant and active growth periods.
Pruning
Black broom is characterized by its upright stems and vibrant yellow flowers. To maintain its shape, enhance air circulation, and remove dead branches, it is best to prune the plant in late spring after it has finished flowering. Every few years, perform rejuvenation pruning to encourage vigorous growth, preserve its ornamental appeal, and reduce the risk of disease.
Botanical profile.
- Plant Type
- Shrub
- Life Cycle
- Perennial
- Genus
- Lembotropis
- Family
- Leguminosae
- Hardiness Zone
- 5-8
- Mature Height
- 30 cm to 91 cm
- Mature Spread
- 49 cm to 91 cm
- Leaf Color
- Green
- Leaf Type
- Deciduous
- Flower Color
- Yellow
- Flower Size
- 0.51 cm to 0.76 cm
- Bloom Time
- Early summer, Mid summer
- Planting Time
- Spring, Summer, Autumn
- Harvest Time
- Late summer, Early fall, Mid fall
Other names.
Reader questions.
How should I water my Black broom plant?
To promote excellent root development, consider using a garden hose at the base of the plant. It's important to avoid spraying water directly on the leaves. If the plant is outdoors and exposed to direct sunlight, the leaves may require more water. Bubblers can be used to moisten the roots of each plant, while soaker hoses can cover the entire garden or bed, especially when adding or removing plants, to ensure deep root penetration. Remember to drain any excess water and allow the soil to dry before watering again. To prevent diseases, it is best to water at ground level. On sunny days, watering the entire bush with water can be beneficial. Whether the plant is in a pot or in the ground, it is important to provide deep watering rather than light sprinkling, especially for Black broom.
Why is it important to fertilize my Black broom?
Fertilizing is essential for the Black broom, as it offers several key benefits. Chiefly, it helps the plant produce beautiful blooms. For optimal flower growth, it is recommended to fertilize the Black broom in early spring. Additionally, fertilizer provides the Black broom with ample energy that it can store in the ground during periods of dormancy. By providing extra nutrients during fall planting or late spring, the Black broom can accumulate more energy to utilize when it enters an active growth phase again.
Does the Black broom plant require specific sunlight care at different stages of its growth?
Tender, new leaves are highly vulnerable to sunburn. It's important to note that very young Black broom plants, particularly during their rapid growth phase in late spring and early summer, are more prone to damage from intense sunlight and heat compared to mature plants or those in a dormant growth stage during the fall. Additionally, Black broom plants freshly obtained from a nursery are typically not accustomed to direct sunlight and require a gradual adaptation process.
What should I do if I give Black broom plant too much or too little water?
If you overwater a Black broom, its leaves may turn yellow, drop off, and wilt. The plant may also look dull and unhealthy, with mushy stems. When you notice these signs, adjust your watering schedule if possible. Wilting can also indicate under watering, in which case the leaves may become crispy and dry. If the soil is dry and watering alone is not enough, give the plant a thorough watering. While this will help the Black broom recover, it may still have dry and yellow leaves for a few days due to root damage. Once the plant returns to normal, the yellowing of the leaves will stop. When keeping a Black broom indoors, check the moisture levels in the pot and avoid overwatering. If you see black spots, allow the soil to dry by withholding water for a few days. Overwatering can lead to root rot, so if you notice discolored and slimy roots, consider transferring the plant to a different pot. Always try to prevent root rot and avoid overly soggy soil. When planting a Black broom outdoors, make sure to check the soil moisture by digging a little deeper. If the soil feels too dry, it may indicate underwatering. Provide adequate watering to help the plant recover.
When should I fertilize my Black broom?
Timing is crucial when fertilizing Black broom. Using fertilizer too early, while the Black broom is still dormant, will render the fertilizer ineffective and it will be washed away by rainwater, causing waste and pollution. To ensure effectiveness, the first application of fertilizer should be in early spring, followed by monthly applications until early summer.
How many hours of sunlight should Black broom receive each day to grow well?
In order for Black broom to grow well, it needs a minimum of 3-6 hours of sunlight per day. Most plants that can tolerate partial sunlight can also do well in full sun. However, since they need less light for photosynthesis, they are more adaptable than plants that specifically need either full sun or part shade.
How often do I need to water my Black broom plant?
The Black broom prefers deep and infrequent watering, especially when planted in pots. It is best to soak them in a gallon of water each time to ensure proper hydration. Potted plants have limited water storage, so the soil dries out faster. In cold regions, watering is needed every 3 to 5 days. Watering should be done early in the morning when the soil is dry, both indoors and outdoors. Check the soil by touching it, and if the top 2-3 inches are dry, it's time to water the plant. During hot days, the soil in the pot can dry out quickly, so it's important to check the moisture daily. If you have a garden, irrigation is necessary, especially in hot climates. Normally, watering once a week is sufficient unless the soil becomes too dry, around 2-3 inches deep. Be mindful of rainfall, as excessive water can lead to root rot. Mulching with 3 to 4 inches of depth is recommended when the plant is outdoors to help conserve water. Sandy soil requires more frequent watering as it drains faster, while clay soil needs less watering, usually every 2-3 days. It can be helpful to mark the watering dates on a calendar and pay attention to any drooping leaves, as they may indicate a slight delay in watering.
When is the best time to not put fertilizer on my Black broom?
To ensure optimal growth of Black broom, it is important to consider the nitrogen content in the fertilizer. Avoid using fertilizers with high levels of nitrogen, as this can result in excessive leaf growth with limited blooms. Instead, opt for a fertilizer that has a lower nitrogen-to-nutrient ratio. Timing is crucial when it comes to fertilizing Black broom. Avoid fertilizing after early autumn, as this can promote excessive growth right before winter. Additionally, refrain from fertilizing during hot and dry periods, as dry soil does not effectively deliver nutrients. Fertilizing during this time can stimulate growth that requires more water, which may not be readily available. It is advisable to apply fertilizer during cooler temperatures earlier in the season. It is worth noting that Black broom can absorb nearby plant or lawn fertilizers. Thus, it is important to be cautious and avoid inadvertently double-dosing the tree or shrub with fertilizers.
What kind of sunlight does Black broom need?
The black broom plant thrives when exposed to full or part sun. It prefers direct morning light, but during summer, it requires protection from the intense afternoon sun. In temperate environments, excessive afternoon sun can harm the plant's appearance and overall health by burning its leaves.
How much water should I give my Black broom?
The Black broom plant typically requires around a gallon of water on a regular basis. For potted plants, it's best to water them until you see the water dripping from the bottom of the pot. Allow the soil to dry before watering again. To determine the amount of water given to your plant in a week, you can use a water calculator or a moisture meter. During the flowering period, provide plenty of water, but allow the moisture to evaporate to avoid root rot. If the Black broom is planted outside and there is sufficient rainfall, it may not need additional watering. However, when the Black broom is young or newly planted, ensure it receives 1-2 inches of rain per week. As the Black broom grows, it can rely solely on rainfall. Only in very hot weather or when there's no rainfall at all for 2-3 weeks, consider watering the Black broom thoroughly during cooler times of the day to prevent damage from high heat. Additional watering will be necessary during prolonged dry periods.
What kind of plant food does my Black broom plant need?
To properly care for your Black broom, it is recommended to use a fertilizer that contains a balanced mix of the three main plant nutrients, with a slightly higher amount of phosphorus. Alternatively, you can enhance the soil by adding organic materials like compost, worm castings, and manure. When the flower buds start to appear, some experienced gardeners supplement with water-soluble fertilizers containing phosphorus 1-2 times. This helps the flowers develop better, resulting in larger and longer-lasting blooms. There are various forms of fertilizers available, but liquid or powdered forms are considered the best for Black broom. Regardless of the form you choose, always dilute the fertilizer and apply it while watering your Black broom for optimal results.
Can the sun harm Black broom? How can I prevent the sun and heat from damaging Black broom?
Indoor black broom plants can be easily damaged by direct sunlight when they are moved outdoors. To prevent sunburns from overexposure, it is best to gradually move the pots from a shaded area to a brighter spot. However, even plants acclimated to the summer sun can be harmed by extreme heat. During a heatwave, it is important to keep the soil consistently moist so that plants can handle the excessive levels of heat. To protect sensitive black broom plants during extreme weather events, consider moving them to areas with afternoon shade or covering them with a shade cloth.