How to Grow Onions with Other Crops: Garlic & Potatoes Guide

Growing your own onions, garlic, and potatoes gives you steady access to fresh ingredients that add flavor to everyday meals. You can grow onions and garlic by planting sets or cloves in well-drained soil, keeping them watered, and harvesting once the tops fall over. Potatoes grow best from seed potatoes placed in loose soil, covered as they sprout, and dug up once the plants yellow and die back.

These crops don’t need complicated care, and they often thrive when planted together in the right conditions. Onions and garlic help deter pests, while potatoes make use of the same garden space in a complementary way. With the right timing, soil preparation, and attention, you can enjoy a harvest that keeps well into the year.

By learning how to plant, care for, and store these vegetables, you set yourself up for a reliable supply that reduces trips to the store and makes your meals more flavorful. Once you understand the basics, you’ll find that growing these staples is both practical and rewarding.

Key Takeaways

• Learn simple steps to plant and grow onions, garlic, and potatoes
• Understand how to care for crops to keep them healthy through the season
• Harvest and store your vegetables to enjoy them long after picking

Essential Steps for Growing Onions and Garlic

Onions and garlic need the right variety, healthy soil, and proper planting methods to produce strong bulbs. Paying attention to these details helps you grow onions and garlic that store well and taste fresh.

Choosing the Right Onion and Garlic Varieties

Start by matching the variety to your climate. Onions are grouped into short-day and long-day types. Short-day onions, such as Red Creole or White Bermuda, grow best in southern regions with mild winters. Long-day onions, like Yellow Sweet Spanish, are suited for northern areas with longer summer days.

Garlic comes in hardneck and softneck varieties. Hardneck garlic, such as German Red, produces a flowering stalk called a scape and thrives in cooler climates. Softneck garlic, like Artichoke types, grows well in warmer regions and stores longer after harvest.

If you are new to growing onions, using onion sets (small bulbs) gives you a head start compared to seeds. For garlic, plant individual cloves from a full bulb. Avoid using grocery store bulbs since they may be treated to prevent sprouting. Instead, buy certified seed garlic or onion sets from trusted suppliers.

Preparing Soil for Optimal Bulb Growth

Onions and garlic both need loose, well-drained soil that allows bulbs to expand. Aim for a soil pH between 6.0 and 7.0. Heavy clay soil should be improved with compost or aged manure to increase drainage and fertility.

Choose a sunny location with at least 6 hours of direct light each day. Standing water or compacted soil can cause rot, so raised beds or mounded rows are helpful in wetter areas.

Before planting, remove weeds and till the soil to at least 8 inches deep. Mix in organic matter evenly. Adding a balanced fertilizer with moderate nitrogen supports early leaf growth, but avoid over-fertilizing since too much nitrogen reduces bulb size.

Crop rotation is also important. Do not plant onions or garlic in the same bed year after year. Rotating helps reduce disease and pest problems that build up in the soil.

Planting Techniques for Onion Sets and Garlic Cloves

Plant onion sets in early spring when soil can be worked. Place them 1–2 inches deep with the pointed end facing up. Space sets 4–6 inches apart in rows about 12–18 inches apart. This spacing allows bulbs to grow without crowding.

For garlic, plant cloves in the fall in most climates, about 4–6 weeks before the ground freezes. In warmer regions, you can also plant in early spring. Set each clove 1–2 inches deep, pointy end up, and space them 4–6 inches apart with rows 6–8 inches apart.

Water both crops after planting to help roots establish. Keep the soil evenly moist but not soggy. Mulching with straw or leaves helps conserve moisture, suppress weeds, and protect garlic during the winter months.

For more details on variety selection and planting schedules, you can review guides such as how to grow garlic and onions that outline climate-specific recommendations.

Cultivating Onions and Potatoes Together

Onions and potatoes can share the same garden bed when you manage spacing, soil health, and timing carefully. Both crops prefer full sun, loose soil, and steady moisture, but their root systems and nutrient needs require thoughtful planning.

Selecting Compatible Potato and Onion Varieties

Choose potato varieties that produce well in your climate, such as Yukon Gold or Russet. These types grow reliably and handle mixed planting conditions. For onions, sweet varieties like Walla Walla or Vidalia are often recommended because they compete less aggressively for nutrients.

Avoid pairing long-season onions with late-maturing potatoes. This reduces the chance of one crop overshadowing the other. Instead, match early or mid-season onions with potatoes that mature in 70–100 days.

Some gardeners note that onions help repel pests like the Colorado potato beetle. Planting the right onion variety can provide this natural benefit while still allowing potatoes to thrive. You can learn more about the potential advantages and drawbacks of pairing these crops from GardenerBible.

Soil Preparation and Bed Design for Mixed Planting

Both onions and potatoes grow best in loose, well-drained soil with plenty of organic matter. Potatoes form tubers underground, so the soil should be deep and friable. Onions have shallow roots, so they need a surface layer that stays moist but not waterlogged.

A raised bed or wide trench system works well. Place potatoes in rows where you can hill soil around them as they grow. Plant onions along the perimeter or in alternating rows to reduce competition.

Adding compost before planting improves fertility and structure. Avoid fresh manure, which can encourage disease. A balanced soil pH between 6.0 and 6.8 supports both crops. Detailed advice on layout and soil needs is available from Stone Post Gardens.

Planting Timelines and Spacing for Onions and Potatoes

Onions should be planted 1–2 inches deep and spaced about 6 inches apart. Potatoes need more space, with seed pieces set 12–18 inches apart and 3–4 inches deep. This spacing prevents overcrowding and ensures each crop has enough nutrients.

Plant both in early spring when the soil is workable. Onions tolerate cool weather, while potatoes prefer soil temperatures above 45°F. Staggering planting by a week or two can help manage growth rates.

Keep rows at least 18–24 inches apart to allow airflow and reduce disease risk. Regular watering is important, but avoid soaking the soil. For more spacing and timing guidance, see Plant4Harvest.

Caring for Your Crops Throughout the Season

Onions, garlic, and potatoes require steady care once planted. Proper watering, fertilizing, mulching, and pest control help ensure healthy growth and good yields. Close monitoring of plant development also prevents common problems before they reduce your harvest.

Watering and Fertilizing Guidelines

Onions and garlic need consistent moisture but dislike soggy soil. Provide about 1 inch of water per week, including rainfall. Potatoes need slightly more, about 1–2 inches per week, especially once tubers begin forming. Water deeply to encourage roots to grow downward.

Use drip irrigation or soaker hoses rather than overhead watering. This keeps foliage dry and reduces the risk of fungal problems such as downy mildew or blight.

Fertilize onions and garlic with a nitrogen-rich fertilizer every 2–3 weeks until bulbs begin swelling. Stop feeding once bulbs push soil aside, as too much nitrogen at this stage delays maturity. Potatoes benefit from balanced fertilizers with potassium and phosphorus to support tuber growth. Avoid excess nitrogen, which produces leafy plants but fewer tubers.

Mulching and Weed Control

Mulching helps conserve soil moisture, suppress weeds, and regulate soil temperature. Apply 2–3 inches of clean straw, shredded leaves, or compost around onions, garlic, and potatoes. Keep mulch light over onions to avoid smothering the bulbs.

Weeds compete heavily with onions and garlic because these crops have shallow root systems. Hand-pull weeds or use a hoe carefully to avoid damaging roots. Potatoes tolerate slightly more competition but still benefit from clean beds.

For potatoes, hilling is a key practice. As plants grow, mound soil or mulch around stems to cover developing tubers. This prevents greening from sunlight exposure and increases yields.

Pest and Disease Management for Allium Crops

Onions and garlic are prone to thrips, onion maggots, and fungal diseases. Rotate crops to new areas of the garden each year to reduce pest buildup. Interplanting onions with carrots or tomatoes can help deter thrips, as noted in onion growing guides.

Garlic is less affected by pests but can suffer from white rot and rust. Remove and destroy infected plants immediately. Avoid composting diseased material.

Potatoes face threats such as Colorado potato beetles, aphids, and late blight. Inspect plants often and hand-pick beetles or larvae. For blight prevention, water at soil level and allow good air circulation. Remove volunteer potato plants that may carry disease from previous seasons.

Monitoring Growth and Preventing Common Issues

Check your crops weekly for signs of stress. Yellowing leaves in onions may indicate nutrient deficiency, while garlic with yellow tips may need more water. Potatoes with curling leaves could signal aphid activity.

Keep track of growth stages. Onions and garlic send up flower stalks when stressed; remove these to keep energy in the bulbs. Potatoes are ready for harvest once vines die back naturally.

Soil conditions matter throughout the season. Compacted soil slows bulb and tuber development. Lightly loosen soil around onions and garlic if it crusts over. Avoid disturbing potato roots once tubers have formed, relying instead on hilling and mulching for protection.

Harvesting, Curing, and Storing Your Onions, Garlic, and Potatoes

You need to pull bulbs and tubers at the right stage, handle them carefully during harvest, and cure them so they last in storage. Each crop has clear signs of readiness and benefits from cool, dry storage conditions to prevent rot and sprouting.

Recognizing Harvest Readiness in Bulbs and Tubers

Onions are ready when the tops fall over and begin to dry. A soft neck and papery outer skin signal maturity. If you wait too long, the bulbs may split or rot.

Garlic is best pulled when half of its leaves have browned. At this point, the bulb wrappers remain intact, which helps with storage. If wrappers break down in the soil, cloves separate and won’t keep well.

Shallots follow a similar pattern to onions. Their tops dry and flop over when bulbs reach full size.

Potatoes should stay in the ground until vines die back. Once the foliage has yellowed and dried, the skins on the tubers will be set. Immature potatoes with thin skins bruise easily and don’t store for long.

Proper Harvesting Techniques

Use a garden fork or shovel to loosen soil before pulling onions, garlic, or shallots. Grip the base of the plant and lift gently to avoid tearing the bulbs. For garlic especially, never yank by the stem, as this can damage the head.

When harvesting potatoes, dig around the plant carefully to avoid cutting into the tubers. A fork works better than a shovel for reducing cuts. Handle each potato gently, since bruises shorten storage life.

Keep harvested crops out of direct sunlight. Sun exposure can cause potatoes to turn green and onions or garlic to dry unevenly. Lay them in a single layer on a shaded surface until you move them to a curing area.

Curing and Storage Methods for Long-Term Freshness

Curing removes excess moisture and toughens skins, which prevents rot. Place onions, garlic, and shallots in a dry, well-ventilated space for 2–4 weeks. The necks should be completely dry and outer skins papery before trimming stems.

Potatoes need different conditions. Cure them in a dark space at 50–60°F with high humidity for about 10 days. This allows small cuts to heal and thickens the skin.

For storage, keep onions and garlic in mesh bags or braided bundles in a cool, dark place with airflow. Avoid sealed containers that trap moisture. Potatoes store best between 35–40°F in darkness. Keep them separate from onions, since gases from onions can cause potatoes to sprout faster.

For more detailed steps on curing and storage, you can review methods from Epic Gardening or Farmers’ Almanac.

Frequently Asked Questions

When you grow onions, garlic, and potatoes, spacing, timing, and plant pairings matter. Paying attention to soil conditions, maturity times, and compatible companions helps you avoid common mistakes and improve harvest quality.

What are the best practices for planting onions and garlic together?

Plant onions about 1 inch deep and 4 inches apart, while garlic cloves should go 2 inches deep and 6 inches apart. Rows should be spaced 12–18 inches apart to allow airflow and growth. Both crops prefer well-drained soil rich in organic matter, such as compost or aged manure.

How long does it take for onions and garlic to mature when grown together?

Onions usually take 90 to 120 days to mature, depending on the variety. Garlic often takes 8 to 9 months from planting to harvest. Since they grow at different speeds, you will likely harvest onions before garlic in the same bed.

What should not be planted next to potatoes when growing them with onions or garlic?

Avoid planting potatoes near tomatoes, peppers, or eggplants. These crops share similar pests and diseases, which can spread quickly. Potatoes also should not be grown too close to carrots, as they compete for nutrients and space.

Are there any companion plants that benefit onions and garlic when planted together?

Carrots, beets, and lettuce grow well with onions and garlic. Their presence helps maximize space and can deter certain pests. Strong-scented herbs like dill and chamomile may also improve the resilience of your alliums.

Can garlic and sweet potatoes be planted in the same garden bed?

Yes, you can plant garlic and sweet potatoes in the same bed if spacing is managed. Sweet potatoes spread widely, so give garlic its own row to avoid crowding. Ensure the soil drains well, since both crops dislike overly wet conditions.

What is the ideal time of year to plant potatoes, onions, and garlic?

Garlic is best planted in the fall for a summer harvest, especially in regions with cold winters. Onions can be planted in early spring or fall, depending on the variety and climate. Potatoes are usually planted in spring once the soil warms to at least 45°F, ensuring steady growth.