Companion Planting Don'ts

A tomato plant withering

As companion planting creates a beneficial bond or “friendship” between plants in the garden, there are also plants that pose as foes to other crops.

Crops to Plant Separately

These plants may hinder or stop growth as they compete for nutrients or space.

Here are some examples of plant combinations that do not work in the garden.

  • Tomato and Cabbage

    Cabbage will stunt the growth of tomatoes and compete for soil nutrients. Plant relatives of cabbage — including cauliflower, collards, and kale — will also hinder the growth of tomatoes.

  • Asparagus and Onions

    Onions and similar plants like garlic will compete for space and can slow or stop plant growth. These plants should be placed far from each other if planted within the same garden.

    Avoid growing asparagus near potatoes for similar reasons.

  • Bell Peppers and Fennel

    Not only is there a competition for space and nutrient that may cause these plants to die or slow in growth, but these plants need different growing conditions.

    Other foes of bell peppers include kohlrabi, walnuts, and apricots.

    Fennel does not do well with other plants and should be placed on its own whenever possible.

  • Cucumbers and Potatoes

    Avoid planting cucumbers and potatoes in the same space or garden bed as they are known to be very competitive for soil nutrients.

    According to, potatoes release substances while growing which will harm the growth of the cucumber.

  • Corn and Tomatoes

    These plants are prone to common fungal infections that may occur in the garden. They also attract insects like the tomato fruit worm and the corn earworm.

Click to See Our Sources

Companion Planting for Bell Peppers” by Unwirklich VinZant,, 11/29/13

Companion Planting In Your Herb Garden” by Robin Svedi,, 1/14/14

Companion Plants: What to Grow with Tomatoes, 2014

What Not To Plant Near Cucumbers” by Casandra Maier, San Francisco Chronicle,, 2014

What to Plant Near Asparagus” by Molly Allman, San Francisco Chronicle,, 2014

What Vegetables Should Not Be Planted Next Each Other in a Garden?” by Valerie Liles, San Francisco Chronicle,, 2014


Pamela Bump

Pamela is the Audience Growth Manager for the HubSpot Blog and holds an M.S. in Media Ventures from Boston University. Before HubSpot, she was Taste for Life’s first Web Editor & Social Media Expert and Harvard Business Review’s first Growth Editor.  In her roles, she’s managed content strategy, social media, and audience growth tactics.

Although her career is focused on digital marketing and editorial innovation, she continues to write for TFL to quench her thirst for food blogging and health journalism.