Crop rotation is the practice of changing or alternating the crops in a given area of the garden. Rotating crops will keep soil nutrients from running out and keep pest and disease problems from getting worse.
Plants that need more nutrients can be switched out for plants that don’t need as much, like legumes, that feed quickly and improve the soil.
If you plant plants from the same family in the same spot in the garden more than three or four times, you can cut down on pest and disease problems.
Onions are a delicious and nutrient-dense vegetable to grow. But after harvesting your onion crop, you’re left with open space in your garden beds. Choosing the right follow-up plants is crucial for maintaining soil health.
Certain crops make excellent onion successors through crop rotation. By thoughtfully sequencing different plant families in the same soil, you can replenish nutrients, prevent diseases, and optimize yields.
Here are 15 great options for what to plant after onions.
Why Crop Rotation Matters
Onions and other alliums like garlic and leeks are heavy feeders. They rapidly deplete nutrients like nitrogen and phosphorus from soil.
Continuous onion planting also allows specialized fungal diseases to accumulate year after year This can severely reduce bulb size and quality.
That’s why crop rotation is key for ongoing onion success. Rotating to unrelated plant families helps restore nutrient balance and break pest and disease cycles in the soil.
15 Ideal Post-Onion Crops
Here are some excellent vegetable choices for rotating through former onion beds:
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Tomatoes – As a nightshade, tomatoes help disrupt onion pests and diseases. Their long summer growth utilizes space during onion dormancy.
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Peppers – Another nightshade, peppers make a great onion rotational partner. Their roots improve soil while deterring allium-specific pathogens.
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Broccoli & Cabbage – These shallow-rooted brassicas thrive after heavy feeding onions. They accumulate leftover nutrients and deter onion pests.
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Carrots & Parsnips – Root crops perform well in lightly fertilized post-onion soils. Their feathery foliage also enhances soil structure.
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Spinach & Lettuce – Quick-growing greens flourish after onions, accumulating minerals in their short roots and deterring allium diseases.
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Beans & Peas – As legumes, beans and peas fix nitrogen back into the soil. They also disrupt disease and pest cycles from alliums.
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Sweet Corn – A grass crop, corn is a great onion follower. Its extensive roots improve soil structure and nutrition.
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Potatoes – Another root crop, potatoes still make a fine onion follower if spaced a few years apart. Their deep roots rebuild soil.
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Melons & Squash – Vining cucurbit crops cover ground and deter weeds after onions, using deep soil nutrients.
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Turnips & Rutabagas – Although susceptible to some shared onion pests, these roots thrive in post-onion conditions later in the season.
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Radishes – Fast-growing radishes are perfect for temporarily occupying empty onion beds before longer season crops.
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Garlic & Leeks – Separate onion relatives by 4+ years in rotation, as they are still susceptible to related soil diseases.
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Cover Crops – Use onion down time to sow soil-enhancing crops like clover, buckwheat, and rye.
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Flowers – Cheerful blossoms like marigolds, nasturtiums, and zinnias improve soil, deter pests, and beautify post-onion beds.
When to Plant After Onions
With proper timing, you can avoid leaving empty space for weeds after clearing onion crops.
In most climates, onions are harvested by mid-summer. Directly follow them with warm season vegetables like tomatoes, peppers, beans, squash, and corn.
For cool weather crops, begin seeds or seedlings 4-6 weeks before your last frost. This gives greens, roots, brassicas and more time to establish before onion harvesting opens up space.
Overwintering onion varieties allow you to further broaden rotation options. After harvesting bulbing onions in summer, plant hardy greens and roots for fall harvesting. Then sow cover crops to enrich the soil throughout winter.
Companion Planting
Strategic companion planting boosts your post-onion crops’ growth and pest resistance:
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Dill, basil, catnip, and marigolds help repel insects on carrots, brassicas, and nightshades after onions.
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Quick growing radishes and salad greens act as pest-attracting trap crops.
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Legumes provide “nitrogen credit” to benefit heavy feeding corn, brassicas, and nightshades.
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Flowers like nasturtiums and calendulas beautify the former onion bed while improving soil.
With mindful crop selection and rotation sequencing, you can keep your garden productive after onion harvests. Proper rotation maintains soil nutrition and prevents disease issues. Combining compatible companion plants further optimizes soil health and plant vigor.
Sample Crop Sequence
Here is an ideal 4-year crop sequence with onions:
Year 1 – Onions
Year 2 – Tomatoes, beans, carrots
Year 3 – Broccoli, lettuce, beets
Year 4 – Corn, cabbage, radishes
Year 5 – Onions again
This alternates plant families to maximize benefits. The year after onions, nightshades tomatoes and beans benefit from reduced onion diseases while fixing nitrogen. Year 3 allows short rooted brassicas and greens to flourish. And the 4th year, extensive rooted corn improves soil before replanting onions.
Follower Crops for Onion Beds
With smart crop rotation, your garden soil recovers its nutritional balance while producing bountiful harvests after onion growing. Use this guide to pick the best followers when planning onions into your overall rotation scheme.
Proper sequencing prevents disease buildup and maintains soil quality. Combined with suitable companion plants, these onion followers deliver optimal yields from your freed-up garden space.
Small garden crop rotation
Crop rotation in small gardens can be difficult; let’s say you only have one or two planting beds. In that case, you can still rotate crops simply to differing spots. You can follow a tomato with a bean one year after the other. If you grow broccoli in the spring or fall, you can switch it out for peas or beans in the spring or summer after. You can also use a green manure cover crop that feeds the soil instead of a heavy feeder. Dwarf white clover and hairy vetch are two examples of cover crops that feed the soil.
Another way to improve or replace nutrients in the soil is to add a lot of aged compost to planting beds before the season starts, after harvest, and as a side dressing during the growing season. However, this is not the same thing as crop rotation.
Benefits of crop rotation
One way crop rotation will help vegetable crops is by keeping soil-borne pests and diseases from building up. Another way is by letting soil nutrients build up and be used efficiently.
Crop rotation means growing different vegetables in the same spot every year instead of the same vegetable or vegetables from the same family.
Plants from the same family shouldn’t be put in the same spot in the garden more than three or four years apart. This will help keep pests and diseases away and replenish the soil’s nutrients.
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Vegetable insect pests tend to feed on similar plants and members of the same plant family. For example, an insect pest that attacks and eats cabbage will lay its eggs before it dies. Insect eggs will hatch if cabbage or a cabbage-related plant is planted in the same spot the next year. The pests will then have everything they need to keep living their life cycle. Soilborne diseases–fungi, bacteria, and viruses–also can be hosted by specific plants as well. Removing host plants or alternating unrelated plants into the garden can break the cycle of pests and disease.
Crop rotation also helps prevent soil nutrients from being depleted. There are many nutrients in the soil that plants need to grow. The most important ones are nitrogen, phosphorus, and potassium. Members of the same vegetable family usually draw the same nutrients from the soil.
Rotating crops will keep the soil from wearing away. Tomatoes and other crops that are high in nitrogen, phosphorus, and potassium are followed by beans, which add nitrogen to the soil, and then onions, which are low in these nutrients.
What to plant after onions and garlic ?
FAQ
What crop to rotate after onions?
What follows onions?
What to do after pulling onions?
What is the best order for crop rotation?
Can you plant beans after onions?
After my heavy feeders or deep-rooting plants have yielded their crops, I plant the soil builders, like peas and beans, and then I go back to planting onions and even other plants in the onion or Amaryllis family, a heavy feeder, and a heavy giver. Legumes, like beans and peas, shouldn’t be planted after onions.
Should you plant onions after harvesting?
Once you have harvested your onions, you should not plant onions or other members of the onion family, asparagus, or legumes like peas and beans. Practicing crop rotation is important if you want your soil to remain balanced, keep pests and diseases at bay, and achieve optimum growth for your vegetables.
Which crops should I plant before or after onions?
These are heavy feeders. Follow lettuce family crops with soil-building legumes. Bean Family (Legume, Leguminosae): Beans and peas, clover, vetch. These crops enrich the soil and soil builders. Plant these crops before or after any other crop family with one exception–do not plant beans after onions.
Can you plant onions after pulling a legume plant?
Beans (both pole beans and bush beans), peas, and other legumes. Onions can kill the helpful bacteria that grows on bean, pea, and other legume roots, stunting the growth. Since these legume plants fix nitrogen to the soil and onions are heavy nitrogen feeders, onions are a great option to plant after pulling your legume plants. Asparagus.
What plants grow well with onions?
While many plants make great companions for onions, there are a few that should be kept separate. Peas and Beans: Peas and beans might seem like harmless neighbors, but they can actually stunt the growth of your onions. These legumes release a compound that inhibits the growth of onion bulbs, resulting in smaller yields.
Can you grow onions near Beans?
You shouldn’t farm onions or any plant inclusive in the allium family close to any beans type. They are likely to cause stunted growth to the beans. Like beans, peas are legumes. Don’t grow onions near any legume plant, including peas. Most farmers warn against growing sage alongside onions as it causes stunted growth to the latter.