Horseradish Companion Plants: Best Partners, Worst Neighbors & Pest Benefits

ByStephen Albert

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Horseradish is one of the most useful companion plants I grow—not just for the spicy roots, but for the way it supports the rest of the garden. After decades gardening in Sonoma Valley and observing horseradish in raised beds, perennial corners, and container plantings, I’ve found it to be a strong natural ally against pests and a steady, low-maintenance neighbor for many vegetables.

In this guide, I’ll walk you through the best companion plants, the worst neighbors, and the pest-suppressing benefits that make horseradish a powerful addition to a productive vegetable garden.

🌿 Why Horseradish Makes a Good Companion Plant

Horseradish grows aggressively underground and forms a strong, sulfur-rich root system that naturally repels several pests. It also grows as both an annual and perennial, giving you flexibility to match it with seasonal crops.

Benefits of Growing Horseradish Near Other Vegetables

  • Repels pests such as aphids, whiteflies, blister beetles, and some soil-borne pests
  • Deters fungal issues due to its antimicrobial compounds
  • Attracts beneficial insects when grown with flowering herbs
  • Thrives on garden edges, saving prime bed space
  • Adds deep taproots that break up compacted soil over time

🌱 Best Companion Plants for Horseradish

After trialing horseradish near dozens of crops over 30 years, these are the combinations that consistently work well.

1. Potatoes

One of the oldest and best companion pairings. Horseradish helps reduce:

  • Colorado potato beetles
  • Aphids
  • Early blight pressure
  • General insect stress

I often plant a single horseradish at the end of each potato row.

2. Brassicas (Cabbage, Broccoli, Collards, Kale)

Horseradish supports brassicas by:

  • Repelling cabbage worms
  • Reducing flea beetle pressure
  • Acting as a perimeter pest deterrent

Avoid crowding—give brassicas their own space, but nearby is ideal.

3. Fruit Trees (Especially Apples and Peaches)

Horseradish helps suppress soil-borne diseases and attracts beneficial insects to orchard edges. I keep horseradish planted at the drip line, never close to the trunk.

4. Beans and Peas

Legumes benefit indirectly from reduced aphid pressure and improved soil tilth. Horseradish doesn’t compete much aboveground, making it a compatible neighbor.

5. Asparagus

Both crops prefer full sun and rich soil. Horseradish’s strong scent helps deter asparagus beetles.

6. Herbs

Especially:

  • Mint
  • Rosemary
  • Oregano
  • Thyme

These drought-tolerant herbs and horseradish coexist well and create a pest-resistant zone in the garden.

🚫 Worst Companion Plants: What to Avoid

While horseradish is adaptable, it has a few incompatibilities.

1. Other Deep Root Crops

Avoid planting close to:

  • Carrots
  • Parsnips
  • Salsify
  • Burdock

Horseradish competes strongly underground and can distort nearby roots.

2. Shallow, Delicate Greens

These include:

  • Lettuce
  • Spinach
  • Arugula

Horseradish’s bold growth can shade them and overwhelm bed space.

3. Fennel

Fennel and horseradish are both allelopathic and should be kept far apart to prevent mutual inhibition.

4. Tomatoes

In my experience, horseradish attracts tomato hornworms rather than repelling them. Keeping tomatoes separated avoids additional stress in hornworm-prone areas.

🐛 Pest Control Benefits of Horseradish

Horseradish emits a strong sulfur-rich aroma and produces compounds that naturally repel or confuse pests.

Repels or discourages:

  • Aphids
  • Whiteflies
  • Cabbage worms
  • Potato beetles
  • Blister beetles
  • Some nematodes

May help reduce:

  • Soil-borne fungal diseases
  • General leaf-feeding pressure on brassicas and potatoes

Planting horseradish at garden edges, row ends, or interspersed between key crops is a strategy I rely on every season.

🧑‍🌾 How to Place Horseradish in the Garden for Best Results

1. Perimeter Planting

Plant on the borders of beds to protect brassicas, potatoes, and greens.

2. Row-End Placement

A classic potato-growing practice that still works exceptionally well.

3. Dedicated “Pest Defense” Corners

Place horseradish in corners of raised beds to create a protective scent barrier.

4. Orchard Integration

Grow at the drip line of fruit trees to support long-term pest resistance.

🌾 My Recommendation

If you’re new to companion planting with horseradish, start by growing it near:

  • Potatoes
  • Cabbage family crops
  • Beans or peas
  • Orchard trees

Avoid planting near carrots or other root crops, and give horseradish room to grow without overwhelming delicate greens.

Horseradish Learning Hub

       Start here: How to Plant and Grow Horseradish: A Complete Guide

Varieties & Growth Methods

Planting & Site Preparation

Garden Companions & Benefits

Care & Maintenance

Pests & Disease Management

Harvesting & Long-Term Patch Management

Storage & Culinary Use

Stephen Albert is a horticulturist, master gardener, and certified nurseryman who has taught at the University of California for more than 25 years. He holds graduate degrees from the University of California and the University of Iowa. His books include Vegetable Garden Grower’s Guide, Vegetable Garden Almanac & Planner, Tomato Grower’s Answer Book, and Kitchen Garden Grower’s Guide. His Vegetable Garden Grower’s Masterclass is available online. Harvesttotable.com has more than 10 million visitors each year.

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