The Best Companion Plants for Asparagus and What to Avoid

Asparagus thrives for 15 years or more when planted with the right neighbors. Good companions help repel pests, improve soil, and maximize space, while poor choices compete for nutrients or harbor harmful insects. After decades of growing asparagus in my California garden, I’ve learned which plants enhance its health and which to keep at a distance.

Table of Contents

Best Companion Plants for Asparagus

Tomatoes

Tomatoes are classic asparagus companions. They repel asparagus beetles with solanine, while asparagus deters nematodes that attack tomato roots.

Tip: Give both crops full sun and rich soil; plant tomatoes on the south side to avoid shading.

Basil and Parsley

Both herbs attract beneficial insects like ladybugs and hoverflies, natural predators of asparagus beetles.

Tip: Interplant small clusters of basil or parsley between asparagus crowns for pest control and fresh herbs.

Marigolds and Nasturtiums

Marigolds deter nematodes, and nasturtiums attract aphids away from asparagus ferns.

Tip: Border your bed with these flowers for color and natural pest management.

Comfrey

Comfrey’s deep roots pull up nutrients and improve soil fertility when leaves are chopped and used as mulch.

Tip: Keep comfrey at the edge of the bed to avoid crowding asparagus crowns.

Spinach and Lettuce

These shallow-rooted greens mature before asparagus spears emerge fully, providing an early-season harvest without competition.

Tip: Sow as a quick spring crop before spears fill in.

Plants to Avoid Near Asparagus

Alliums (Onions, Garlic, Leeks)

These strong-scented plants can inhibit asparagus growth and compete for nutrients.

Potatoes

Heavy feeders that disturb the soil during harvest, stressing asparagus crowns.

Fennel

Releases compounds that inhibit the growth of many vegetables, including asparagus.

My Experience and Key Takeaways

Pairing asparagus with tomatoes and basil has been especially successful in my garden—fewer beetles, healthier ferns, and tastier tomatoes. Avoiding potatoes and onions near my beds has prevented nutrient competition and ensured consistent spear size year after year.