Garlic, known for its pungent aroma in the culinary world, often sparks curiosity regarding its influence in gardens. Beyond its culinary uses, could it also serve as a natural pest repellent?
We previously looked at it’s potential use of keeping cats away from your garden or allotment, but what about harmful bugs and pests?
The Nature of Garlic’s Repellency
Garlic (Allium sativum) is part of the Allium family, encompassing onions, leeks, and chives. These plants produce compounds like allicin when their tissues are damaged. Allicin not only provides the characteristic aroma but also possesses antimicrobial properties.
In the Garden: While growing, garlic plants don’t typically emit a strong aroma unless they’re damaged. However, this mild scent and the plants’ compounds can have repelling effects on certain pests.
Garlic’s Impact on Garden Pests
- Pest Deterrence: Certain insects and pests seem to be discouraged by garlic. Aphids, which often plague rose gardens, might be less prevalent when garlic is planted nearby.
- Natural Pesticides: Some gardeners create a garlic-infused spray by steeping crushed garlic in water. This spray, when applied to plants, can deter pests like aphids, beetles, and whiteflies. However, it’s crucial to test the spray on a small part of the plant first to ensure it doesn’t cause damage.
- Soil Pests: There’s some evidence to suggest that planting garlic might deter soil-borne pests and nematodes. The sulfur compounds found in garlic can act as a natural fumigant in the soil.
Side note: Dreaded Aphids
Aphids, often called plant lice, are tiny, soft-bodied insects that are among the most pervasive and destructive pests for plants. These minuscule pests feed by piercing the vascular system of plants and sucking out their sap. In doing so, they deprive the plant of vital nutrients, leading to various issues such as yellowing leaves, stunted growth, and curled foliage.
Furthermore, as they feed, aphids excrete a sticky substance called honeydew, attracting other insects and fostering the growth of sooty mould, thereby inhibiting photosynthesis.
Additionally, aphids are vectors for various plant viruses, spreading disease as they move from plant to plant. Their rapid reproduction rate and ability to resist many chemical pesticides further compound the challenge of controlling them, making them a significant concern for gardeners and farmers alike.
Companion Planting with Garlic
Companion planting with garlic offers a holistic approach to garden management, leveraging the inherent properties of garlic to foster healthier plant growth and deter pests.
Garlic, with its pungent odour, is a natural repellent for many pests, including aphids, Japanese beetles, and even certain root pests. For instance, garlic can help keep aphid populations at bay when grown near roses. Furthermore, garlic has antifungal properties, making it useful in preventing diseases like powdery mildew, which affects crops like cucumbers, squash, and melons.
Note: The close presence of garlic may inhibit legumes like peas and beans.
As with any companion planting strategy, understanding the symbiotic relationships between plants is key. Planting garlic strategically amidst other crops can reduce the need for chemical interventions, promoting a more organic and sustainable gardening approach.
Conclusion: Garlic’s Role in a Healthy Garden
While garlic might not be a one-size-fits-all solution for all garden pests, it undoubtedly offers benefits in the realm of organic pest control. Integrating garlic into a garden promises a delicious harvest and might lead to a healthier, more balanced ecosystem.
Brian Sheridan has an allotment in Edgbaston and is a competitive grower. Brian is also a keen photographer and loves cooking. Brian and his wife Mary will also be running a stall at Edgebaston artisan market this year, selling products made from the allotment, including his award-winning relish!