Verbascum chaixii, the nettle-leaved mullein, is a species of flowering plant in the genus Verbascum, native to Spain, France, Italy (including Sicily), the former Yugoslavia, and Greece. It is considered a good plant to attract pollinators. With Verbascum bombyciferum it is a parent of the 'Pink Domino' cultivar, which has gained the Royal Horticultural Society's Award of Garden Merit.
Nettle-leaved mullein has strong resistance to disease and is generally not prone to illness. Still, it can be affected by pests and diseases present in its surroundings. These problems are typically mild. Regarding care, this plant needs moderate maintenance. It should be pruned regularly to keep a neat appearance and encourage healthy growth. Fertilizing can also help stimulate flowering. Nettle-leaved mullein is appropriate for anyone with outdoor space, such as a garden or patio, and does not demand extensive gardening experience. It may need more attention when grown indoors.
How to keep Verbascum Chaixii.
Light
The nettle-leaved mullein prefers abundant light, which promotes healthy development. It naturally occurs in places that are not shaded. Too much shade or excessively strong light can adversely affect its growth. These sun-loving plants can adjust to different light levels at various stages of their development.
Water
Nettle-leaved mullein, which typically grows on rocky slopes, does best in well-drained soil with moderate moisture. To support optimal growth, especially during the flowering season, water the plant weekly. This schedule complements natural rainfall, ensuring the plant remains consistently hydrated without being overwatered.
Temperature
When grown in its native temperate regions, nettle-leaved mullein prefers temperatures of 68 to 95°F (20 to 35°C). Extra care is required if the temperature falls below or rises above that range.
Fertilizer
The ideal time to fertilize a Nettle-leaved mullein is early spring, when it is coming out of dormancy and beginning active growth. Fertilizing supplies essential nutrients for healthy growth. Although Nettle-leaved mullein has relatively low fertilizer requirements, applying fertilizer once a year can improve its survival and encourage better, longer-lasting flowers.
Pruning
The nettle-leaved mullein is characterized by tall spikes and woolly leaves, and it thrives with careful pruning. To maintain its shape and encourage blooming, prune the plant from early to late spring. Thinning out crowded sections can improve air circulation and reduce the risk of disease, leading to a healthier and more vibrant display.
Botanical profile.
- Plant Type
- Herb
- Life Cycle
- Perennial, Biennial
- Genus
- Verbascum
- Family
- Scrophulariaceae
- Hardiness Zone
- 5-9
- Mature Height
- 91 cm
- Mature Spread
- 46 cm
- Leaf Color
- Green, Silver, Blue, Gray
- Leaf Type
- Semi-evergreen
- Flower Color
- White, Yellow
- Flower Size
- 2.03 cm to 3.05 cm
- Bloom Time
- Summer
- Planting Time
- Spring, Summer, Autumn
- Harvest Time
- Late summer, Early fall, Mid fall
Other names.
Reader questions.
How should I water my Nettle-leaved mullein plant?
To ensure the health of your Nettle-leaved mullein, it is best to water it with filtered water at room temperature. Tap water may contain harmful particles, so filtering it is recommended. The plant prefers warm conditions, so avoid using cold water as it can be a shock. It's also important to avoid watering from above, as this can cause problems with the foliage. Instead, soak the soil with your filtered room temperature water until it is completely saturated. This will benefit the plant by moisturizing the roots and helping them absorb essential nutrients as they continue to spread through the soil.
Why should I add fertilizer to my Nettle-leaved mullein?
Fertilization is important for the Nettle-leaved mullein for various reasons. It provides essential nutrients for the plant's growth above and below the ground. Despite that, Nettle-leaved mulleins have relatively low fertilization needs and can sometimes survive well without it. However, annual fertilization can greatly benefit the plant by keeping it alive and promoting the development of better and longer-lasting flowers. Therefore, if you want your Nettle-leaved mullein to thrive, make sure to fertilize it on a yearly basis.
What are the sunlight requirements for nettle-leaved mullein?
Nettle-leaved mullein thrives in environments that provide ample exposure to sunlight, ideally above 6 hours of sunlight daily. It's important to observe how sunlight travels through your garden to find spots that offer a good balance of light and shade, ensuring the plants' well-being. The plant originates from areas where it is not overshadowed, and while it can adapt to various light conditions during different growth stages, both overly shaded areas and excessively strong light can adversely affect its growth.
What are the ideal growing temperatures for nettle-leaved mullein?
Nettle-leaved mullein, with its botanic name Verbascum chaixii, thrives in its native temperate regions at temperatures ranging from 68 to 95°F (20 to 35°C). It's important to closely monitor and adjust the plant's environment when temperatures fall below or rise above this comfort range to ensure its health and growth.
What should I do if I give my Nettle-leaved mullein too much water or not enough water?
Both overwatering and underwatering can harm your Nettle-leaved mullein, but overwatering is more common. Excessive water can cause wilting and yellowing of the stems and leaves. It can also lead to diseases like root rot, mold, and mildew, which are fatal to the plant. The Nettle-leaved mullein is somewhat drought-tolerant, so underwatering is less likely. However, it can still happen, resulting in brittle and brown leaves. It's important to identify signs of overwatering promptly, as some diseases may become irreversible if not addressed early. Reduce watering if you notice these signs and consider replacing poorly draining soil with a loose, well-draining potting mix. If you see signs of underwatering, simply water more regularly until the plant recovers.
When should I fertilize my Nettle-leaved mullein?
To give your Nettle-leaved mullein the best start for the year, it's ideal to fertilize it in late winter or early spring. This is when the plant is coming out of its dormant phase and starting to grow actively. Fertilizing at this time promotes healthy growth. Fertilizing in the early spring is generally the most beneficial, but it's also possible to fertilize in the fall. However, it's not recommended to feed the mullein during summer or winter.
How does artificial lighting support indoor nettle-leaved mullein plants?
When natural sunlight is not sufficient, especially during winter or in less sunny spaces, artificial lighting can be a vital solution for indoor plants. Indoor nettle-leaved mullein requires adequate lighting to ensure optimal growth. LED lights are recommended as they can be customized to provide specific wavelengths needed by the plants. Full sun plants need 30-50W/sq ft, partial sun plants require 20-30W/sq ft, and full shade plants should have 10-20W/sq ft of artificial light. The light source should be placed 12-36 inches above the plant to mimic natural sunlight, and the duration should match the natural daylight hours, typically 8-12 hours per day.
Does nettle-leaved mullein need special frost protection during winter?
Nettle-leaved mullein exhibits strong cold resistance and does not usually require special frost protection measures during winter. However, in conditions where winter temperatures are forecasted to drop below -25°C, it's crucial to protect the plant. This can be accomplished by covering it with soil or straw to insulate it against the extreme cold. To assist in its survival through winter and early spring, watering the plant abundantly before the first freeze in autumn to keep the soil moist is also recommended.
How often should I water my Nettle-leaved mullein plant?
If your Nettle-leaved mullein is in a pot, the easiest way to determine if it needs water is by checking the soil with your finger. If the top two to three inches of soil feel dry, then it's time to water it. For outdoor Nettle-leaved mullein plants planted directly in the ground, you can also use this method. If the first few inches of soil are dry, then it's time to water. Typically, during spring and early fall, watering once a week is sufficient. However, during extremely hot weather, you may need to water twice or more per week. However, it's important to note that mature, well-established Nettle-leaved mullein plants have a remarkable ability to withstand drought.
When is the best time to not fertilize my Nettle-leaved mullein?
It is best to fertilize your Nettle-leaved mullein in the late winter or early spring. This plant doesn't require much fertilization, so a single annual feeding should be enough. If you continue to fertilize during the spring, summer, and fall, you risk overfertilization and all the associated problems. The only exception is if you didn't fertilize in the spring, in which case it is okay to feed the plant in the fall. Additionally, it is not necessary to fertilize during the winter. The Nettle-leaved mullein is in a dormant phase during this time and doesn't undergo new growth. Therefore, it is not recommended to fertilize in most of the winter.
What are the symptoms of light deficiency or excess in nettle-leaved mullein?
Symptoms of light deficiency include smaller new leaves, leggy or sparse growth, early leaf drop to conserve resources, slower or halted growth, and lighter-colored new leaves indicating insufficient chlorophyll. Excessive sunlight can cause chlorosis (leaves turning yellow), sunscald (pale or necrotic areas on the plant), leaf curling, wilting from increased water loss, and leaf scorching (brown, dry edges on leaves). These symptoms highlight the plant's struggle in inappropriate lighting conditions.
How does low temperature affect nettle-leaved mullein, and what are the solutions?
Nettle-leaved mullein is cold-tolerant and performs best in temperatures above 20°C. It should be kept above 0°C during winter. At temperatures falling below -25°C, while there may not be obvious changes during the winter, the plant may experience decreased sprouting or no sprouting at all come springtime. If such a situation occurs, it is advised to remove any parts of the plant that have failed to sprout in the spring as a solution to encourage new growth.