17 Leek Companion Plants (and Some to Avoid)

If you’re growing leeks this season, the secret to a thriving, healthy garden might be found in the plants growing right beside them. In this companion planting guide, we’ll explore the best leek companion plants to boost growth, attract beneficial insects, and provide natural pest control, whether you’re working with a small garden design or growing leeks in containers. You’ll also learn how to plant leeks, improve your soil, and discover a few clever leek gardening tips for success from seed to harvest. Ready to learn what leeks are, how to grow them well, and even how to prep leeks for your next meal? I’ve got all that for you, plus a handy leek companion plant chart. Let’s dig in!

What Are Leeks?

Leeks are mild, sweet vegetables in the onion family. They have long white stalks and green tops and are often used in soups, stews, and savory dishes for a delicate onion-like flavor. I like to use them in soups (keep reading for an easy leek soup recipe). I’m always looking for plants that will grow well in my USDA Plant Hardiness Zone 8b yard and garden. Most recently,

I planted some leeks amongst some strawberry plants in a border bed on the edge of our driveway. There are many good companion plants for leeks (and a few plants to avoid). If you’re interested in adding leeks to your garden repertoire, read on!

Leek Companion Plants: Flowers

Some of the best leek companion flowers help attract pollinators, deter pests, and add beauty to your garden. Great choices include:

Marigolds – Repel nematodes and aphids while brightening the bed.

Calendula – Attracts beneficial insects like hoverflies and ladybugs.

Chamomile – Improves the flavor and health of nearby leek plants.

Nasturtiums – Work as a trap crop for aphids, keeping leeks safe.

Alyssum – Draws in pollinators and beneficial insects for natural pest control.

Leek Companion Plants: Fruit

While most leek companion plants are vegetables or herbs, a few fruiting plants can also make excellent companions. The best leek companion fruit options include:

Strawberries – Their shallow roots don’t compete with leeks, and they help suppress weeds.

Tomatoes – Provide light shade in hot climates and benefit from leeks’ pest-repelling scent.

Melons – Leeks help deter aphids and beetles that often target melon vines.

Cucumbers – (Technically a fruit!) Grow well with leeks for mutual pest resistance.

Leek Companion Plants: Herbs

Some of the best leek companion herbs not only boost flavor but also help with natural pest control and attracting beneficial insects. Top choices include:

Thyme – Deters cabbage worms and complements leeks in cooking.

Sage – Repels carrot flies and enhances soil health.

Mint – Helps repel aphids and onion flies (just keep it contained).

Dill – Attracts ladybugs and other beneficial insects for a healthy garden.

Leek Companion Plants: Vegetables

Some of the best leek companion vegetables can help boost growth, improve soil health, and provide natural pest control. Great choices include:

Carrots – Benefit from leeks’ pest-repelling scent and loosen soil for better growth.

Celery – Grows well with leeks and helps retain soil moisture.

Beets – Thrive alongside leeks without competing for nutrients.

Lettuce – Makes great use of space and provides a living mulch for leeks.

What Not to Plant with Leeks

Here’s a quick guide on what not to plant with leeks:

Legumes (peas and beans) – Compete for nutrients and can stunt leek growth.

Alliums (garlic, onions, shallots) – Attract the same pests, increasing risk of disease.

Brassicas (broccoli, cauliflower, cabbage) – May attract pests that also target leeks.

Keeping these plants away from leeks helps reduce pest problems and ensures a healthy, productive garden.

Leek Companion Planting Chart

Leek Companion Plants
Leek Companion Plants: Flowers	Leek Companion Plants: Fruit
Alyssum	Cucumbers
Calendula	Melons
Chamomile	Strawberries
Marigolds	Tomatoes
Nasturtiums
	Leek Companion Plants: Vegetables
Leek Companion Plants: Herbs	Beets
Dill	Carrots
Mint	Celery
Sage	Lettuce
Thyme
	Worst Leek Companion Plants
	Beans
	Broccoli
	Cabbage
	Cauliflower
	Garlic
	Onions
	Peas
	Shallots

 

Growing Leeks in Containers

Here are some brief tips for growing leeks in containers:

Choose a deep container at least 10–12 inches to allow long roots to develop.

Use loose, rich soil mixed with compost for good drainage and soil improvement.

Plant leek seedlings about 6 inches apart and water consistently.

Feed with a balanced fertilizer every few weeks.

As leeks grow, add more soil around the stems (called blanching) to keep them tender and pale.

Place the container in full sun for best results.

Leek Gardening Tips: How to Plant Leeks

To plant leeks, start seeds indoors 8–10 weeks before the last frost or use young seedlings. Prepare fertile, well-drained soil enriched with compost, then transplant seedlings about 6 inches apart. Plant them deep, burying the lower stem to encourage long, tender stalks, and water consistently. As they grow, hill soil around the stems to blanch them for pale, flavorful leeks.

Leeks can also be planted in the fall in USDA Plant Hardiness Zones 7 and higher. September or early October plantings of seedlings outdoors will allow enough time for roots to develop and plants to establish themselves for a winter harvest.

Common Leek Pests and Diseases

Here’s a brief guide to common leek pests and diseases and simple remedies:

Onion Fly (larvae) – Causes wilting and holes in the base. Remedy: Use floating row covers and rotate crops each year.

Leek Moth – Leaves tunnels in leaves. Remedy: Remove affected leaves and use insect netting.

Aphids – Cluster on leaves and suck sap. Remedy: Spray with water or insecticidal soap, and attract beneficial insects.

Rust (fungus) – Orange pustules on leaves. Remedy: Remove infected leaves, ensure good airflow, and rotate crops.

Downy Mildew – Greyish mold on leaves. Remedy: Avoid overhead watering and improve spacing for airflow.

How to Prep Leeks

To prep leeks, start by trimming off the dark green tops and root ends. Slice them lengthwise and rinse thoroughly under running water, fanning the layers to remove dirt and sand. Once clean, chop or slice as needed for your recipe.

Easy Leek Soup Recipe

Ingredients:

3–4 leeks, cleaned and sliced (white and light green parts)

2 tablespoons butter, avocado oil, or olive oil

1 medium potato, peeled and diced

4 cups vegetable or chicken broth

Salt and pepper to taste

Optional: cream or herbs for garnish

Instructions:

In a large pot, sauté leeks in butter or olive oil over medium heat until soft.

Add diced potato and cook for 2–3 minutes.

Pour in the broth, bring to a boil, then simmer for 20 minutes until vegetables are tender.

Blend the soup until smooth using an immersion blender or regular blender.

Season with salt and pepper, and optionally stir in a splash of cream or garnish with fresh herbs, like chopped chives.

Serve warm and enjoy!

Need More Planting Ideas?

Check out the tips for the best companion plants for eggplant to learn what to grow with those beauties. If you like the idea of companion planting, you might be interested in reading about the best companion plants for pumpkins, sunflowers, garlic, tarragon, asparagus, rosemary, radishes, beetroot (beets), thyme, parsley, lupine, borage, peonies, apple trees, or the best companion plants for lavender. Get tips for growing stunning dahlias or vintage roses. Are you a beginning gardener? Try planting some foolproof, easy-care perennials, or learning about the best companion plants for columbine. There are so many exciting plants to grow!

Keep Track of Your Garden with a Journal Logbook

Now that you have learned about some compatible companion plants, keep track of your planting ideas, goals, and plans with a printable, editable free garden journal logbook. Choose the pages you want to use and customize them as you wish to record monthly, weekly, and daily garden tasks, lists, weather, and planting arrangements. There are also grid pages for easily designing the layout of your vegetable garden, flower garden, or landscape. Print it out and put it into a notebook you can take with you to the garden (that’s what I do). It’s nice to have all of your garden information in one place.

Get the garden journal logbook!

Free Online Garden Planner Layout Template

With so many companion plant ideas, you might need a way to plan your garden layout. Whether you are planting vegetables, flowers, or herbs, this online garden planner can help you visualize your design and bring it to life. Arrange and rearrange the plants over and over, then print the layout when you are satisfied. With garden tasks that need your attention, this is one way to save time.

Have a wonderful week, and may all of your leek-growing endeavors meet with success!

Lisa Mitchell is a wife, mom, and school librarian who likes to grow fruit, herbs, vegetables, and flowers on her family’s small Pacific Northwest farm. To learn more about what this website has to offer gardeners, click on over to the Garden page.

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