Herbs are a wonderful addition to any garden, offering culinary, medicinal, and aesthetic benefits. However, some herbs are known for their aggressive growth habits and can quickly become invasive if not managed properly. It’s important to understand the nature of these plants and take precautions to prevent them from overtaking your garden and spreading to wild areas.
In this article, I’ll introduce you to ten herbs that have the potential to become invasive. I’ll provide details on their native origins and the reasons why they need to be planted with care. Whether you’re an experienced gardener or just starting, knowing which herbs require extra attention will help you maintain a healthy and balanced garden.
Mint
Mint (Mentha spp.) is a popular herb native to Europe, Asia, and North America. Known for its refreshing scent and flavor, mint is a favorite in teas, desserts, and savory dishes. However, it is also notorious for its aggressive growth. Mint spreads rapidly through underground runners, making it difficult to contain once established.
One of my favorite ways to manage mint is by planting it in containers. This method keeps its vigorous roots in check while allowing you to enjoy its benefits. If you choose to plant mint directly in the garden, consider using barriers to prevent it from spreading. Regular pruning can also help control its growth. Mint’s invasiveness is a testament to its resilience, but with proper care, it can be a delightful addition to your garden.
Lemon Balm
Lemon Balm (Melissa officinalis) is a fragrant herb native to Europe and the Mediterranean region. Its lemon-scented leaves are used in teas, salads, and medicinal preparations. While lemon balm is valued for its soothing properties, it can become invasive due to its prolific seed production and vigorous growth.
To prevent lemon balm from taking over your garden, plant it in containers or raised beds. Regularly deadhead the flowers to reduce seed dispersal, and trim the plants back to keep them manageable. Lemon balm’s rapid growth can be a challenge, but its delightful aroma and uses make it worth the extra effort to control.
Oregano
Oregano (Origanum vulgare) is a hardy perennial herb native to Europe and Central Asia. It is a staple in Mediterranean cuisine, known for its robust flavor. However, oregano can spread aggressively through underground stems, especially in favorable conditions.
One of the reasons I love growing oregano is its resilience and drought tolerance. To keep it from becoming invasive, consider planting oregano in containers or using root barriers. Regular harvesting and pruning will also help maintain its size and prevent unwanted spread. With careful management, oregano can thrive in your garden without overtaking it.
Chives
Chives (Allium schoenoprasum) are a versatile herb native to Europe, Asia, and North America. Their mild onion flavor makes them a popular choice for garnishing and seasoning dishes. Chives spread through both seed and underground bulbs, which can lead to them becoming invasive if not controlled.
I enjoy growing chives for their easy care and lovely purple flowers. To keep chives from spreading uncontrollably, remove spent flower heads before they go to seed and divide the clumps every few years. Planting chives in containers can also help manage their spread. With a bit of attention, chives can be a manageable and attractive addition to your herb garden.
Fennel
Fennel (Foeniculum vulgare) is a hardy perennial herb native to the Mediterranean region. It is prized for its feathery foliage, aromatic seeds, and edible bulb. However, fennel can become invasive, especially in mild climates where it can reseed prolifically.
One of my favorite aspects of fennel is its versatility in the kitchen. To prevent fennel from spreading, harvest the flower heads before they set seed and keep an eye on any seedlings that may appear. Growing fennel in containers or designated garden beds can also help contain its growth. Fennel’s invasiveness can be managed with regular maintenance, allowing you to enjoy its culinary benefits.
Comfrey
Comfrey (Symphytum officinale) is a fast-growing perennial herb native to Europe and Asia. It is known for its large leaves and bell-shaped flowers, as well as its use in herbal medicine and composting. Comfrey can become invasive due to its vigorous growth and deep root system.
I appreciate comfrey for its numerous benefits, including its ability to improve soil fertility. To control comfrey’s spread, plant it in a contained area or use root barriers. Regularly cutting back the foliage can also help keep it in check. Comfrey’s aggressive nature can be an asset in certain situations, but it’s important to manage its growth to prevent it from taking over your garden.
Catnip
Catnip (Nepeta cataria) is a perennial herb native to Europe and Asia. It is well-known for its effects on cats and its use in herbal teas and remedies. Catnip can become invasive due to its prolific seed production and vigorous growth.
One of my favorite things about catnip is watching my cats enjoy it! To prevent catnip from spreading uncontrollably, remove flower heads before they go to seed and consider planting it in containers. Regular pruning will also help manage its size and spread. Catnip’s rapid growth can be a challenge, but with proper care, it can be a fun and useful herb in your garden.
Valerian
Valerian (Valeriana officinalis) is a perennial herb native to Europe and Asia. It is known for its fragrant flowers and medicinal roots, which are used as a natural sedative. Valerian can become invasive due to its vigorous growth and ability to self-seed.
I love valerian for its calming properties and beautiful flowers. To keep valerian from taking over your garden, deadhead the flowers before they set seed and plant it in containers or designated garden beds. Regular maintenance and pruning will help manage its spread. Valerian’s potential invasiveness can be controlled, allowing you to enjoy its benefits without worry.
Tansy
Tansy (Tanacetum vulgare) is a hardy perennial herb native to Europe and Asia. It is known for its bright yellow, button-like flowers and its use in traditional medicine and insect repellent. Tansy can become invasive due to its prolific seed production and aggressive growth.
One of the reasons I enjoy growing tansy is its ability to repel pests naturally. To prevent tansy from spreading uncontrollably, remove flower heads before they go to seed and plant it in contained areas. Regular pruning and maintenance will also help manage its growth. Tansy’s vigorous nature can be an asset in pest control, but it’s important to keep it in check to avoid it becoming a nuisance.
Creeping Thyme
Creeping Thyme (Thymus serpyllum) is a low-growing perennial herb native to Europe. It is valued for its aromatic leaves and tiny, fragrant flowers, making it a popular choice for ground cover and borders. Creeping thyme can become invasive due to its ability to spread quickly and form dense mats.
I love using creeping thyme in my garden for its beauty and fragrance. To manage its spread, plant creeping thyme in contained areas or use root barriers. Regular trimming and dividing can also help keep it under control. Creeping thyme’s aggressive growth can be managed with proper care, allowing you to enjoy its benefits without it overtaking your garden.
