Crop rotation is a centuries-old agricultural practice that helps improve soil structure, reduce the risk of pests and diseases, and optimise nutrient availability.
We previously looked at whether it’s a OK to plant garlic after potatoes, but what comes next?! After harvesting garlic and onions, it’s wise to consider which crops will thrive when planted in their wake.
Understanding Crop Rotation
Crop rotation involves planting different plant families in a sequence over several seasons or years. This breaks the life cycles of pests and diseases specific to certain crops, while also ensuring that soil nutrients are used and replenished in a balanced manner.
Why Rotate After Garlic and Onions? Garlic and onions are members of the Allium family. Continuous planting of the same family can deplete the soil of specific nutrients and increase susceptibility to pests like onion maggots or diseases such as white rot.
Ideal Successors to Garlic and Onions
- Leafy Greens and Brassicas:
- Broccoli, cabbage, kale, and Brussels sprouts are excellent choices. These plants require high nitrogen levels, which might be available after harvesting the Allium family.
- Legumes:
- Beans and peas can be planted as they help fix nitrogen back into the soil, rejuvenating it for future crops.
- Root Vegetables:
- Carrots, beets, and parsnips can benefit from the well-draining soil often preferred by garlic and onions. These crops also have different nutrient requirements, ensuring a balanced use of soil resources.
- Solanaceous Crops:
- Tomatoes, peppers, and potatoes can be considered. However, ensure these haven’t been planted in the same spot for the past couple of years to avoid issues like blight.
Plants to Avoid
- Other Alliums:
- Avoid planting leeks, shallots, or any other Allium family member immediately after garlic and onions to reduce the risk of perpetuating pests and diseases.
What to do after lifting garlic?
After harvesting garlic, the soil in which it grew is left in a state of transition, and managing it correctly can optimise its health for future plantings.
Firstly, removing any remaining garlic roots and foliage is advisable to prevent potential diseases from lingering. Incorporate organic matter, such as compost or well-rotted manure, to replenish the nutrients that the garlic has absorbed. This will enhance the soil structure and boost its fertility.
If the soil previously showed signs of pests or diseases like white rot, consider rotating your crops to prevent these issues from recurring.
Garlic, being a heavy feeder, can exhaust the soil of essential nutrients, so you might also want to test the soil’s pH and nutrient levels to ensure it’s well-balanced for the next crop.
Finally, planting a green manure or cover crop, such as clover or rye, can suppress weeds, prevent soil erosion, and improve soil health in the next planting season.
Conclusion: Planning for Soil Success
Planting the right successors to garlic and onions is a step towards sustainable gardening. By understanding the principles of crop rotation and the specific needs of different plants, gardeners can ensure a productive and healthy garden year after year. Always keep local conditions in mind, and for region-specific advice, refer to UK gardening societies and publications.
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!