24 May 2013, written by Barbara Pleasant
From spring to fall, vegetable gardens undergo constant change. When spring crops are ready to be picked in the middle of summer, a big change happens because there is room for new plants. But what should they be? What to plant after early potatoes? What to plant after peas?.
You might think these questions are too soon, but you need to answer them now if you want to make the most of the next big planting window. Having strong seedlings ready to plant as soon as the old crops are gone is often the best way to get the best results and not waste any valuable growing season time. This is known as succession planting or relay planting. For instance, if you start leeks, squash, kale, or Brussels sprouts seeds in the next few weeks, you can put them in the ground as soon as there is room.
Of course, you’ll want to switch between plant families to keep the soil healthy and prevent the spread of diseases that come from the soil. And there is another factor to consider when planning midsummer vegetable crop rotations. If you grow garlic, shallots, or any other onion family plant, and then leave bits of root in the soil, they may stop some legumes from growing. On the other hand, they may help leafy greens and tomato family plants grow.
Onions are a tasty and easy-to-grow vegetable that no garden should be without. But once your onion crop is finished, you’re left with empty space in your vegetable beds. So what should you plant after harvesting onions?
Following onions with the right crops is important for maintaining soil health through crop rotation. By rotating different plant families through the same beds, you can disrupt pest and disease cycles while balancing soil nutrients.
In this article, I’ll share 15 great options for what to plant after onions I’ll also discuss optimal crop rotation schedules and companion planting combinations to get the most out of your garden!
Why Crop Rotation Matters After Onions
Onions and other alliums like garlic and leeks are heavy feeders that deplete nutrients like nitrogen and phosphorus from soil. They are also susceptible to fungal diseases that can linger in the soil.
Continuously replanting onions or related crops in the same spot allows pests and diseases to build up, resulting in declining yields over time.
That’s why crop rotation is so important for onion beds. Rotating to unrelated plant families helps “reset” the soil, disrupt disease lifecycles, and restore a balance of nutrients.
Following a 3-4 year rotation schedule is ideal for optimal onion harvests. You should avoid sowing onions, leeks, garlic, or chives in the same area for at least 3-4 years.
15 Excellent Options for Rotating After Onions
Here are some great plant choices for your post-onion rotation:
1. Tomatoes
Juicy tomatoes are a warm season crop that makes a perfect onion follow. As a nightshade, tomatoes help disrupt allium pests and diseases. Tomatoes also occupy garden space during onion dormancy.
2. Peppers
Another nightshade, peppers complement onions in a rotation scheme. Their deep roots improve soil structure while deterring onion-specific pathogens.
3. Broccoli & Cabbage
These brassicas flourish after onions and other heavy feeders. Their shallow roots accumulate leached nutrients, and sulfur compounds deter allium pests.
4. Carrots & Parsnips
Carrots and parsnips thrive when lightly fertilized soils follow nitrogen-hungry onions. Their feathery leaves also improve soil structure.
5. Beets
Another root veggie that performs well after onions and other heavy feeders. Beets have a broad nutrient profile, deterring specific diseases.
6. Sweet Corn
A grass-family crop, corn makes an excellent rotation choice after onions or any allium. Tall corn stalks outcompete weeds while extensive roots improve soil.
7. Beans & Peas
Legumes like bush beans and peas are great onion followers. They fix nitrogen into the soil and don’t share common pests with alliums.
8. Spinach & Lettuce
Quick-growing greens like spinach and various lettuces flourish in post-onion beds. Shallow roots accumulate minerals, and many deter allium diseases.
9. Radishes
Another fast grower, radishes are great for filling empty onion beds for a quick harvest. Fast growth outpaces diseases while aerating soil.
10. Turnips & Rutabagas
Turnips and rutabagas share onion pests but occupy different seasons, making them less susceptible. These root crops appreciate onions’ soil conditioning.
11. Melons & Squash
Vining cucurbit crops cover ground and outcompete weeds after onions. They utilize deep soil nutrients while deterring allium pests above and below ground.
12. Potatoes
A fellow root crop, potatoes still make a good onion follower if spaced 3-4 years apart. Their deep roots accumulate leached nutrients and improve structure.
13. Garlic & Leeks
Although in the same family as onions, garlic and leeks are less susceptible to diseases. A lengthy 4-year-plus rotation is still advised between alliums.
14. Cover Crops
Use the post-onion window to sow cover crops like clover, rye, or buckwheat. They’ll boost soil nutrition for the next hungry allium crop.
15. Flowers
Blooming annuals like marigolds, zinnias, or nasturtiums make the onion bed aesthetically pleasing while improving soil health.
This covers a wide range of plant families suited for following onions! Combine appropriate cool and warm season crops to keep beds occupied.
When to Plant After Onions
Timing your crop rotation correctly ensures beds aren’t left empty for weeds to take over.
In most climates, onions are harvested by mid-summer. This opens up space for warm season crops like tomatoes, peppers, beans, melons, squash, and corn. These can be planted immediately after clearing spent onion plants.
For cool weather crops, sow seeds or transplant starts 4-6 weeks before your last spring frost. This allows time for broccoli, cabbage, greens, root crops, and more to establish before onion harvesting.
Overwintering onion varieties expand your rotation options. After harvesting bulbing onions in summer, follow with cold hardy greens and root crops for fall harvest. Then plant cover crops to enrich the soil over winter.
Companion Planting With Post-Onion Crops
Rotating compatible plants together boosts growth and deters pests. Some smart companion plants for post-onion crops include:
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Dill and chervil to repel pests on carrots, beets, and brassicas after onions.
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Marigolds, nasturtiums, and catnip as insect-repelling complements to tomatoes, broccoli, melons.
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Legumes to provide “nitrogen credit” to heavy feeding corn, potatoes, and brassicas following onions.
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Quick growing radishes to serve as trap crops, luring pests away from other vegetables.
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Basil and other aromatic herbs to disguise the “empty” onion bed from pests.
Using companion planting principles when rotating crops maximizes the benefits of your onion crop sequence.
Through mindful crop sequencing and rotation, your garden soil can recover from onion crops while producing abundant other vegetables. Use this guide to select the best suited followers when planning onions into your beds.
Proper rotation keeps soils healthier and prevents buildup of onion diseases. And combining compatible companions deters pests for optimal plant growth.
What to Plant After Lettuce and other Leafy Greens?
The first crops to lose quality and bolt are leafy greens like lettuce, mustard, spinach, and arugula. The plants grow longer and bloom as the days get longer faster, which quickly earns them a spot in the compost heap. Most gardeners agree that bush beans are the best vegetable to plant after lettuce because they grow quickly in warm soil and produce a lot in late summer. After planting lettuce, you can also grow carrots, cucumbers, squash, or a second crop of basil to last you all summer. And if you’ve always wanted to grow Brussels sprouts, your spring salad garden might be the right spot for them.
What to Plant After Garlic or Onions?
Like leafy greens, garlic and onions get ready to be picked when the days get longer. The garlic bulbs are ready to be lifted and cured in midsummer, and the onions a few weeks later. Even before that, I have room to plant again once the winter onions and leeks I planted in the fall have been brought inside.
You don’t have to plant an onion or a legume after garlic or onions. There are many other things you can do. In my climate, I can plant winter squash or pumpkins that grow quickly after garlic, but only if I have strong seedlings growing in containers that are ready to plant as soon as the bed has been tilled to add new compost and balanced organic fertilizer. Rutabagas direct-seeded into a bed previously occupied by alliums works well in terms of time, too. If you live in a place with a long growing season, you can plant peppers and tomatoes after garlic or onions. In cooler climates, Chinese cabbage or bok choy may be the perfect choice.
