Lupinus angustifolius is a species of lupin known by many common names, including narrowleaf lupin, narrow-leaved lupin and blue lupin. It is native to Eurasia and northern Africa and naturalized in parts of Australia and North America. It has been cultivated for over 6000 years as a food crop for its edible legume seeds, as a fodder for livestock and for green manure.
Narrow-leaved lupin shows strong resistance to diseases and is typically not susceptible to them. Still, it can be affected by pests and diseases present in its environment, though such infections are generally mild. Regarding upkeep, the plant needs a moderate level of care. It should be pruned on a regular basis to preserve its appearance and encourage healthy growth. Applying fertilizer can also support better flowering. This lupin is appropriate for anyone with outdoor areas like a garden or patio and does not demand extensive gardening experience. It may need extra attention if cultivated indoors.
How to keep Lupinus Angustifolius.
Light
The narrow-leaved lupin grows best with steady sunlight, though it can tolerate some shade. Still, too much shade will restrict its growth, while overly intense sun can scorch its leaves. Originating from areas with plentiful sunshine, it is therefore well adapted to bright conditions.
Water
Narrow-leaved lupin, a plant native to the Mediterranean region, thrives in climates with mild winters and dry summers. While it is drought-resistant, watering it weekly will promote optimal growth. Maintaining consistent moisture during the growing season enhances both foliage and flower development.
Humidity
This plant will thrive in moderate humidity, which is probably the level in your home. However, misting it a few times a week can be very beneficial. Make sure the room has good ventilation.
Temperature
Narrow-leaved lupin originates from climates where temperatures range from 68 to 95°F (20 to 35℃). It does best within this temperature band, and large deviations from it can negatively affect its growth.
Fertilizer
For best development, Narrow-leaved lupin needs three fertilizer applications: one before planting, a second about one month after seedlings emerge, and a third 1 to 1.5 months after the second. Some Narrow-leaved lupin types also benefit from an extra fertilizer application at planting to aid rapid growth.
Pruning
Narrow-leaved lupin flourishes when pruned properly, with the best time being early to late spring. Concentrate on removing dead stems and lightly trimming any overgrown areas to improve the plant's shape and airflow. Consistent maintenance helps prevent disease and encourages blooming. For the best results, always use clean, sharp tools.
Botanical profile.
- Plant Type
- Herb
- Life Cycle
- Annual, Biennial
- Genus
- Lupinus
- Family
- Fabaceae
- Hardiness Zone
- 7-9
- Mature Height
- 30 cm to 61 cm
- Mature Spread
- 20 cm to 40 cm
- Leaf Color
- Green, Blue
- Leaf Type
- Deciduous
- Flower Color
- Blue, Purple, White
- Flower Size
- 3.05 cm to 30.48 cm
- Bloom Time
- Late spring, Early summer, Mid summer
- Planting Time
- Spring, Summer
- Harvest Time
- Mid summer
- Native Area
- Libya, Egypt, Turkey, Tunisia, Montenegro, Cyprus, Bulgaria, Greece, Croatia, Morocco, Serbia, Lebanon, Portugal, Syria, Italy, Spain, Israel, Albania, Algeria, France
Other names.
Reader questions.
How often should I water my Narrow-leaved lupin plant?
To properly care for narrow-leaved lupin, it's important to water it regularly throughout the growing season. In spring, watering once a week should suffice. However, as the weather gets warmer, you may need to increase your watering to two or three times a week. It's crucial not to exceed this rate as it can harm the plant. It's also important to maintain relatively moist, but not wet, soil for the narrow-leaved lupin. Keep in mind that watering a narrow-leaved lupin in a pot is different. The soil in a pot tends to heat up and dry out faster than ground soil, so you'll need to water more frequently. Generally, watering a potted narrow-leaved lupin a few times a week is reasonable, compared to once a week for a plant in the ground.
If I fertilize my Narrow-leaved lupin too much, what will happen?
First-time gardeners, as well as experienced gardeners experimenting with new products, often fall into the trap of over-fertilizing their plants. Narrow-leaved lupin, however, provides clear warning signs when it is receiving too much food. Look out for yellowing leaves, wilting foliage, and under-developed blooms - these are all indications that the plant is being overfed. Frequent fertilization of Narrow-leaved lupin can create hostile soil conditions, known as "too hot" soil, which burns the plant's roots due to excessive saturation of minerals, nutrients, or compost. To prevent this, it is advisable to flush out the soil by watering it twice as much as usual, ensuring good drainage, once a month or so.
What are the sunlight requirements for Narrow-leaved lupin?
Narrow-leaved lupin thrives best with consistent exposure to sunlight but can tolerate some shade. It requires full sun, meaning above 6 hours of sunlight daily, or partial sun, approximately 3-6 hours of sunlight daily. However, it's important to observe how sunlight moves through your garden to ensure that your plants receive the perfect balance of light and shade, ensuring their happiness and growth.
What is the native climate for Narrow-leaved lupin?
Narrow-leaved lupin, botanically known as Lupinus angustifolius, is native to climates where temperatures range between 68 to 95°F (20 to 35°C). It thrives best within these temperature parameters, and significant deviations from this range can negatively affect its growth. This plant exhibits strong cold resistance, meaning special frost protection measures are typically not required during winter. However, in instances where winter temperatures are anticipated to fall below -15°C, it is crucial to provide cold protection. This can be achieved by covering the plant with soil or straw and ensuring the soil remains moist before the first freeze in autumn to prevent drought and water scarcity during the winter and early spring months.
How should I water my Narrow-leaved lupin plant?
To water Narrow-leaved lupin, you can use a variety of common watering tools such as a garden hose with a spray nozzle or a watering can. The plant is not too specific about the type of water it receives, as it can survive with rainwater, tap water, or filtered water. Avoid watering from overhead as it can harm the leaves and flowers and potentially lead to disease. Setting up a drip irrigation system is often the best method for watering this plant, as it provides even and direct water distribution to the soil. When watering a Narrow-leaved lupin that is grown in a container, you can follow a similar approach but use tools like a cup, watering can, or tap to apply water directly to the soil.
Why should I fertilize my Narrow-leaved lupin?
Plants need nutrients to survive. Most gardeners understand this, including both experienced and inexperienced ones. Without proper nutrition, Narrow-leaved lupin will die shortly after pollination. So, providing the right nutrients in the right amounts is crucial for keeping Narrow-leaved lupin alive and producing beautiful flowers throughout the blooming season. Using fertilizer also helps build a strong and healthy root system for Narrow-leaved lupin. Since its root system is delicate, fertilizing at planting time is especially important. It helps create a stable foundation for the plant and paves the way for a remarkable flowering display. By timing the fertilization correctly, the flowering period of Narrow-leaved lupin can be significantly extended.
Can Narrow-leaved lupin adapt to different lighting conditions?
Yes, the Narrow-leaved lupin is adaptable to different lighting conditions due to its origin in sun-rich habitats. While it prefers ample sunlight, it can endure some shade. Nevertheless, too much shade can inhibit its growth, and excessive sunlight may lead to leaf scorch. For indoor plants, artificial lighting can be a beneficial supplement, especially during less sunny periods or in locations with insufficient natural light. Options like LED lights aid in providing the required wavelengths, with specific wattage per square foot based on the plant's sun requirements.
How does Narrow-leaved lupin react to low temperatures?
Narrow-leaved lupin is cold-tolerant and demonstrates optimal growth when temperatures are maintained above 20°C. During winter, it is essential to ensure that the plant's environment does not drop below 0°C. If temperatures fall below -15°C, while no immediate changes may be observable during winter, there could be a reduction in sprouting or an absence of sprouting come springtime. In such cases, the recommended solution is to remove any plant parts that have failed to sprout in spring, helping the plant to rejuvenate and possibly recover for the growing season.
What should I do if I give too much or too little water to my Narrow-leaved lupin?
If you underwater your Narrow-leaved lupin, simply water it more often. Overwatering can be a bigger problem, as it can lead to diseases and death. To prevent this, choose a sunny location with good drainage. If your potted lupin is overwatered, consider changing the pot to one with better drainage. Repot it with loose soil in a pot that drains well.
When should I fertilize my Narrow-leaved lupin for best results?
Narrow-leaved lupin experiences rapid growth in the early part of the growing season. It is recommended to fertilize the plant during this time, specifically at the time of planting. Whether you plant it in the ground or in planters, this initial application of fertilizer is crucial. It will be the only dose of fertilizer until later in the year, when the plant is in full bloom. Once the season is in full swing and the Narrow-leaved lupin has opened most of its blooms, it's time to start fertilizing again. This should be done every three to four weeks, depending on the weather, when the blooms are at their peak output. However, once the plant begins to produce fewer new blooms, it is no longer necessary to fertilize.
What are the symptoms of inappropriate lighting for Narrow-leaved lupin?
Narrow-leaved lupin may show several symptoms if it does not receive adequate light. Insufficient light can lead to smaller leaves, leggy or sparse growth, faster leaf drop, slower or halted growth, lighter-colored new leaves, and conditions such as chlorosis or leaf scorching. Excessive sunlight can cause symptoms like sunscald, leaf curling, wilting, and leaf scorching. These symptoms indicate the plant's struggle with its current lighting conditions.
How does Narrow-leaved lupin react to high temperatures?
In the summer, it is crucial to ensure that the Narrow-leaved lupin is not exposed to temperatures exceeding 35°C. When the temperature surpasses this mark, reaching upwards of 38°C, the plant's leaves may become lighter in color, exhibit curling, become susceptible to sunburn, and in severe cases, the entire plant may wilt and dry out. To mitigate these effects, it is advisable to trim away any sunburned and dried-up parts of the plant. Relocating the plant to a shaded area during the peak sun hours of midday and afternoon or utilizing a shade cloth can provide necessary protection. Additionally, watering the plant in the morning and evening will help maintain soil moisture and support the plant's health under high temperature stress.