Can You Plant Onions and Potatoes Together? A Guide to Growing these Companion Crops

Onions and potatoes are two of the most popular vegetables to grow in home gardens. They have similar soil and sunlight requirements, making them great candidates for companion planting. But is it really a good idea to plant onions and potatoes together?

In this article, we’ll explore the pros and cons of growing onions and potatoes together. You’ll learn about ideal spacing, timing, and layout to maximize the benefits of this pairing. We’ll also go over what varieties work best and how to avoid common mistakes when interplanting onions and spuds.

The Benefits of Onions and Potatoes as Companion Crops

Onions and potatoes can be very successfully grown together Here are some of the benefits this combo can provide

• Pest control: Onions help repel aphids, potato beetles, cabbage worms, carrot flies, and other common garden pests. The pungent sulfur compounds they release mask the scent of the potatoes.

• Reduced disease Onions have antifungal properties that can suppress soil fungi and reduce instances of blight

• Space efficiency: The shallow roots of onions don’t compete much underground with potato tubers. Above ground, the onion tops die back before the potato vines spread out.

• Flavor enhancement Some gardeners report better taste from potatoes and onions grown together

• Weed suppression: Dense plantings of onions helps block light and suppress weeds.

When interplanted properly, onions and potatoes can boost yields and growth for both crops.

Potato and Onion Companion Planting Considerations

While onions and potatoes generally make great companion plants, there are a few things to keep in mind:

• Spacing: Do not plant onions and potatoes too close together. Overcrowding causes competition for nutrients, light, and moisture.

• Shading: Onion tops will shade out very young potato plants if planted too closely.

• Soil needs: Potatoes and onions both prefer nutrient-rich, loose, well-draining soil. Ensure the bed has plenty of compost worked in.

• Water: Consistent moisture is important for both crops. Mulch and diligent watering is key.

• Crop timing: Onion’s early harvest works well with potato’s longer growth habit. But potatoes do best planted a few weeks before onions.

With good spacing and timing, onions and potatoes can thrive together. Avoid overcrowding for best results.

Ideal Onion Varieties to Grow with Potatoes

The key is choosing mild, non-bulbing onion varieties so the onions don’t take up too much space underground:

• Scallions: Easy to tuck in around potatoes. Harvest while small.

• Bunching onions: Grow in dense clumps with shallow roots.

• Evergreen bunching: Doesn’t form bulbs. Long harvest window.

• Chives: Compact perennial. Mild onion flavor.

• Garlic chives: Flat leaves with garlic flavor. Tolerates shade.

Avoid large bulbing onion varieties like Copra or Red that need more underground space. Focus on compact onion types that play nice with potatoes.

Best Potato Varieties for Onion Companion Planting

When selecting your spud variety, prioritize shorter season, compact plants. These potatoes will mature around the same time as onions:

• Yukon Gold: Classic yellow potatoes. Compact plants, 65-75 day maturity.

• Red Norland: Early season red skin potatoes, 60-70 day maturity.

• French Fingerling: Small oblong tubers, 65-75 day maturity.

• Baby Creamer: Round mini potatoes, 60-70 days.

• Purple Viking: Dark purple skin, round tubers. 65 days.

Avoid long season potatoes like russets. Focus on quick maturing potatoes that won’t sprawl out.

5 Tips for Planting Potatoes and Onions Together

Follow these guidelines to successfully plant onions and potatoes together:

1. Loosen the soil and mix in several inches of compost or aged manure before planting.

2. Plant potatoes first 2-3 weeks before onions to give them a head start. Space rows 12-18 inches apart.

3. Wait for potato sprouts to emerge, then plant onion sets, seeds or transplants around them.

4. Allow 6-8 inches between onions and potato plants to prevent crowding.

5. Hill potatoes carefully to avoid disturbing onion plants. Mound soil up around stems.

With good timing and proper spacing, you can avoid competition between your onions and potatoes.

Common Mistakes to Avoid with Onion and Potato Companion Planting

When interplanting onions and potatoes, be sure to avoid these common mistakes:

• Planting onions and potatoes too close together leading to crowding and reduced yields.

• Using long season onion varieties that need more underground space, causing competition with potatoes.

• Sowing onions and potatoes at the same time. Potatoes need a 2-3 week head start.

• Blocking sunlight from potatoes by planting onions too close to young plants.

• Forgetting to hill potatoes which can cause tubers to push up above ground.

• Neglecting to provide even moisture. Inconsistent watering causes stress and reduced yields.

• Not preparing soil well by loosening and amending with compost before planting.

With attention to timing, plant selection, placement and care, onions and potatoes can thrive together. Avoid cramped quarters for best results.

Sample Onion and Potato Companion Planting Layouts

Here are two sample layouts that make efficient use of space while avoiding overcrowding:

Layout 1: Onions between potato rows

• Space potato rows 12-18 inches apart
• Once sprouts emerge, plant onion sets in between rows
• Allow 6-8 inches between onion sets and potato plants

Layout 2: Onions on one side of bed

• Plant two rows of potatoes on one side of bed
• On the other side, plant a block of onions
• Leave 12-18 inches between potato rows and onions

The key in both layouts is ensuring adequate space between the onion plants and potato mounds for care and growth.

Growing Onions and Potatoes in Containers

It’s possible to grow potatoes and onions together in pots, but tub crowding can be an issue. Follow these tips:

• Use at least a 15-20 gallon container.
• Add compost to potting mix for nutrition.
• Plant onions along edges of pot.
• Place 3-4 potato pieces in center with 8 inches between onions.
• As foliage grows, keep onions trimmed to prevent crowding.
• Hill up potting mix around stems as potatoes grow.

Even with good spacing, yields are lower when grown this way. In-ground planting is better for bountiful harvests.

Harvesting and Storing Onions and Potatoes Together

• Onions can be harvested after tops yellow and flop over.
• Cure bulbs for 2 weeks protected from rain before storing.
• Potatoes are ready to dig once vines die back and skin is set.
• Cure potatoes 1-2 weeks in cool, dark place to maximize storage life.
• Both can be stored together in mesh bags or crates in cool, dark place.

Curing and proper storage helps both crops last for months after harvest!

Frequently Asked Questions About Companion Planting Onions and Potatoes

Still have questions about growing onions and potatoes together? Here are answers to some common queries:

Why shouldn’t onions and potatoes be planted close together?

Too close proximity causes competition for nutrients, moisture and space. It can reduce yields and growth for both crops.

What are the best potato varieties to plant with onions?

Choose shorter season, compact varieties like Yukon Gold, Red Norland and fingerlings. Avoid long season potatoes.

Is it better to plant onions from seeds or sets with potatoes?

Onion sets are recommended as they mature faster than seeded onions. You want onions that bulb quickly with potatoes.

Can you plant garlic with potatoes?

Yes! Garlic works just like onions as a beneficial companion for potatoes. Follow similar guidelines for spacing and timing.

What about shallots or leeks planted with potatoes?

Shallots and leeks also make great companions for potatoes! Space them appropriately and avoid crowding.

The key is remembering that both onions and potatoes need sufficient space to grow underground and above ground. Pay close attention to spacing, crop timing, and variety selection. With smart companion planting, your onion and potato harvest will be bountiful.