Companion Planting with Onions: Plants to Grow With and Avoid
Onions are fantastic companion plants that can improve garden health by repelling pests and enhancing growth. But not all plants thrive when grown near onions. After decades of gardening experience, I’ve learned which neighbors work best and which to keep apart.
Best Plants to Grow With Onions
- Carrots: Onions repel carrot flies; carrots loosen soil for better onion roots.
- Lettuce: Onions can deter aphids and other pests that target leafy greens.
- Beets: Both have different nutrient needs and don’t compete heavily.
- Tomatoes: Onions can help repel aphids and other tomato pests.
- Strawberries: Onions improve pest resistance and don’t compete for resources.
Plants to Avoid Planting Near Onions
- Beans and Peas: Legumes and onions inhibit each other’s growth.
- Sage: Tends to stunt onion growth when planted too close.
- Asparagus: Both have strong flavors and allelopathic effects that reduce growth.
- Fennel: Strong allelopathic properties make fennel a poor neighbor for onions.
My Experience Tip
Planting onions alongside carrots and lettuce has consistently reduced pest issues in my garden, leading to healthier crops and higher yields.
Companion Planting Chart for Onions
| Good Companion Plants | Why They Work Well | Plants to Avoid | Reason to Avoid |
|---|---|---|---|
| Carrots | Onions repel carrot flies; improve soil | Beans & Peas | Inhibit each other’s growth |
| Lettuce | Onions deter aphids and pests | Sage | Stunts onion growth |
| Beets | Different nutrient needs, minimal competition | Asparagus | Allelopathic effects reduce growth |
| Tomatoes | Onions repel tomato pests | Fennel | Strong allelopathic properties |
| Strawberries | Improve pest resistance, no competition |
Onion Growing Hub
Start here: The Ultimate Onion Growing Guide: From Seed to Harvest
🌱 Planning & Varieties
- How to Choose the Best Onion Varieties for Your Region – Match flavor, storage, and climate to your garden.
- Daylength and Onion Growth: Understanding Short, Intermediate, and Long-Day Varieties – Pick the right type for your latitude.
- Growing Bulb Onions: Pick the Right Variety for Your Garden – Choose the right variety for where you live.
- Onion Sets vs. Seedlings vs. Seeds: Which Is Best for Your Garden? – Pros and cons of each planting method.
🌿 Planting & Starting
- Step-by-Step Guide to Starting Onion Seeds Indoors Successfully – Timing and troubleshooting for strong transplants.
- Planting Onions Seeds and Sets – Here’s how to get started.
- How to Grow Onion Sets – You can grow your own onion sets from seed for next year.
- Growing Onions in Containers: Soil, Pots, and Care Tips – Small-space planting success.
- How to Grow Green Onions, Spring Onions, and Scallions – Learn how these alliums differ.
- How to Plant, Grow, and Harvest Welsh Onions – Learn to grow these mild-flavored members of the onion family.
🌞 Care & Maintenance
- Watering Onions for Optimal Growth: Techniques and Tips – How much and how often to water.
- Feeding and Fertilizing Onions: Organic and Synthetic Options – Nutrient needs for strong bulbs.
- Companion Planting with Onions: Plants to Grow With and Avoid – Beneficial pairings and plants to avoid.
- Onion Family Growing Problems: Pest, Disease, and Problem Controls – Natural control of thrips, maggots, and more; identifying and treating fungal or bacterial problems.
🧅 Harvest & Storage
- How to Harvest Onions at Peak Maturity for Best Storage – Signs onions are ready and how to cure.
- How to Harvest and Store Onions – Here are the basics for harvesting and storing onions.
- Onion Storage Techniques: Keep Your Harvest Fresh for Months – Best environments for long-term keeping.
🍳 Using Your Onions
- Cooking with Onions: Recipes and Tips to Bring Out Flavor – From fresh salads to caramelized dishes.
- How to Make Onion Soup with No Recipe – Enjoy this tasty classic!
