Ultimate Guide to Companion Planting in the Vegetable Garden: Everything You Need to Know

There are so many great reasons for companion planting and so many benefits for your garden that it's hard to think of reasons why you wouldn't. From natural pest control to improving soil quality and just making your beds look nicer, companion planting is a great way to improve your vegetable garden.

But while that's all well and good, companion planting problems can crop up on occasion. Because of this, it's important to learn about the downsides of companion planting as well as the beneficial aspects before practicing this common vegetable gardening technique.

Let’s dig into the basics of what companion planting is, some of the pros and cons of this organic gardening practice, and the best vegetables to grow side by side.

What Is Companion Planting?

Companion planting is the practice of growing two or more plants together in order to benefit one or more of those plants. This is a common gardening technique that offers a number of purported benefits, including pest control, improved flavor, increased yields, healthier soil, and more.

There isn’t much scientific backing to support the benefits of companion planting. But there are generally few drawbacks to trying it in your garden. It’s a popular practice in many organic gardens.

Many companion plants are ones you may already grow together in your garden. By simply taking the time to plot out where you plant them first so the companions are together, you can potentially improve your garden’s performance.

Benefits of Companion Planting

Companion planting is all about using plants to benefit other plants. Here are some of the ways companion plants can help one another.

1. Natural Pest Control

Pest control is one of the most common uses for companion planting. Some companion plants deter pests with their strong scents. Others actually attract pests, but by planting them in your garden you draw harmful bugs away from your precious veggies. These types of companion plants are called trap crops.

Using companion plants as natural pest control is a centuries-old practice. Of all the companion planting benefits, this one is among the most practical and crop-saving. Examples of companion plants to control pests include marigolds, which help suppress nematodes, and nasturtiums, which pull aphids away from tomato plants.

Other companion plants attract beneficial insects, which will help keep destructive insects in check. You can also use companions to attract beneficial insects, such as using dill or fennel to attract ladybugs, predators that eat pests. These uses for companion plants help to decrease the amount of pesticides you use and the effort it takes to keep your garden pest-free.

2. Extended Blooming

Companion planting benefits can also be purely aesthetic. Plant the right flowering perennials together in a bed and you will get continuous blooms from spring through fall. Mix ornamental and edible plants for a gorgeous vegetable garden that looks good all season.

3. Natural Trellis

Some plants go well together because one grows tall, strong, and upright while the other needs a trellis for support. Grow corn next to pole beans, for instance, and the beans have a natural support system.

4. Improved Soil Fertility

Some companion plants work to make your soil richer. For example, including legumes like clover or peas in a bed will add nitrogen to the soil to help enrich it and benefit other plants in the bed. Grow companion plants that improve your soil for a natural dose of fertilizer.

5. Nurse Cropping

Growing two crops together that benefit each other is called nurse cropping. An example is growing lettuce with broccoli. The broccoli grows early and quickly, and provides shading leaves for the slower-growing lettuce. The shade protects the lettuce and prevents it from bolting.

6. Increased Yields

Another benefit to companion planting is that it can increase harvest yields. This may happen for a number of reasons, like extra protection, improved soil, or lack of pests. But no matter the exact cause, when vegetable plants are happy and healthy, they produce bigger and healthier crops. This means you get more food from the same space.

Drawbacks of Companion Planting

Though companion planting is a common practice, its apparent benefits aren’t backed by science. This doesn't mean I'm totally against the idea of planting companions in the garden – in fact, I quite often do. But for anyone toying with the idea, you should be aware that there are downsides of companion planting, too.

1. It's Not an Exact Science

As previously stated, most companion planting advice is not backed up by proven scientific fact. Most claims are just that – based on information passed down through the years. Because of this, results differ from place to place and gardener to gardener. Although some people claim certain plants to be good and useful, to others these same plants can prove to be nightmares.

Take those nasturtiums, for example. They are said to ward off many pesky insects but they attract aphids. So if you plan on adding them to the garden alongside your crops, plan on losing your harvest to aphid pests.

Marigolds, too, aren't always a sure bet. I have planted them for years with my tomatoes and other vegetable crops in the hopes of warding off would-be offenders only to still have the plants fall victim to the very insects the flowers were meant to repel.

2. Efficacy Can Vary by Environment

Temperature, soil moisture, soil pH, sunlight, and nutrient availability all differ for each plant and these variables can also continually change in the garden. So while you may think your plants may happily grow together, less adapted species may not survive. These variables can also influence the growth of other plants more equipped to thrive in areas where those before did not, like weeds.

3. Not All Plants Are Compatible

Most plants that share similar growing conditions are considered to be good companions. When you take on companion planting, the plants must be compatible and, frankly, there are a number of plants that don't like each other.

They must have similar growing conditions and share nutritional needs. Not all of them do. Without taking the time to research beforehand, it can be difficult to know which plants work well together until it's too late.

There are other factors to take into consideration too. For instance, some plants, like sunflowers, release toxic compounds that can affect others growing nearby. These allelopathic toxins can inhibit seed germination and growth, which may be good for reducing those overactive weeds but not good if you're hoping to grow seeds or seedlings there.

Does Companion Planting Actually Work?

There are many reasons to try companion planting in the garden and these far outweigh any disadvantages you may come across. That said, you need to be aware that it may or may not work for every individual.

It may take a little extra time and consideration, but companion planting will help you get the most out of your garden if you do your homework to ensure that each plant in the garden will "play nice” with its neighbors. As long as you don't expect perfect results every time, companion planting is a beneficial practice any gardener can easily try.

Best Plants for Companion Planting

Here are the best companion planting options to try for common vegetables.

 Asparagus

• Basil
• Parsely
• Pot Marigold
• Tomatoes

Beets

• Bush beans
• Broccoli
• Brussels sprouts
• Cabbage
• Cauliflower
• Chinese Cabbage
• Garlic
• Kale
• Kohlrabi
• Lettuce
• Onions

Broccoli

• Beets
• Celery
• Cucumbers
• Dill
• Garlic
• Hyssop
• Lettuce
• Mint
• Nasturtium
• Onions
• Potatoes
• Rosemary
• Sage
• Spinach
• Swiss Chard

Brussels Sprouts

• Beets
• Celery
• Cucumbers
• Dill
• Garlic
• Hyssop
• Lettuce
• Mint
• Nasturtium
• Onions
• Potatoes
• Rosemary
• Sage
• Spinach
• Swiss Chard

Bush Beans

• Beets
• Broccoli
• Brussels Sprouts
• Cabbage
• Carrots
• Cauliflower
• Celery
• Chinese Cabbage
• Corn
• Cucumbers
• Eggplant
• Garlic
• Kale
• Kohlrabi
• Peas
• Potatoes
• Radishes
• Strawberries
• Swiss Chard

Cabbage

• Beets
• Celery
• Cucumbers
• Dill
• Garlic
• Hyssop
• Lettuce
• Mint
• Nasturtium
• Onions
• Potatoes
• Rosemary
• Sage
• Spinach
• Swiss Chard

Carrots

• Beans
• Chives
• Lettuce
• Onions
• Peas
• Peppers
• Radishes
• Rosemary
• Sage
• Tomatoes

Cauliflower

• Beets
• Celery
• Cucumbers
• Dill
• Garlic
• Hyssop
• Lettuce
• Mint
• Nasturtium
• Onions
• Potatoes
• Rosemary
• Sage
• Spinach
• Swiss Chard

Celery

• Beans
• Broccoli
• Brussels Sprouts
• Cabbage
• Cauliflower
• Chinese Cabbage
• Chives
• Garlic
• Kale
• Kohlrabi
• Nasturtium
• Tomatoes

Corn

• Beans
• Cucumbers
• Melons
• Parsley
• Peas
• Potatoes
• Pumpkin
• Squash
• White Geranium

Cucumber

• Beans
• Broccoli
• Brussels Sprouts
• Cabbage
• Cauliflower
• Chinese Cabbage
• Corn
• Kale
• Kohlrabi
• Marigold
• Nasturtium
• Oregano
• Peas
• Radishes
• Tansy
• Tomatoes

Eggplant

• Beans
• Marigold
• Peppers

Kale

• Beets
• Celery
• Cucumbers
• Dill
• Garlic
• Hyssop
• Lettuce
• Mint
• Nasturtium
• Onions
• Potatoes
• Rosemary
• Sage
• Spinach
• Swiss Chard

Kohlrabi

• Beets
• Celery
• Cucumbers
• Dill
• Garlic
• Hyssop
• Lettuce
• Mint
• Nasturtium
• Onions
• Potatoes
• Rosemary
• Sage
• Spinach
• Swiss Chard

Lettuce

• Beets
• Broccoli
• Brussels Sprouts
• Cabbage
• Carrots
• Cauliflower
• Chinese Cabbage
• Chives
• Garlic
• Kale
• Kohlrabi
• Onions
• Radishes
• Strawberries

Melons

• Corn
• Marigold
• Nasturtium
• Oregano
• Pumpkins
• Radishes
• Squash

Onions

• Beets
• Broccoli
• Brussels Sprouts
• Cabbage
• Chamomile
• Cauliflower
• Carrots
• Chinese Cabbage
• Kale
• Kohlrabi
• Lettuce
• Peppers
• Strawberries
• Summer Savory
• Swiss Chard
• Tomatoes

Parsley

• Asparagus
• Corn
• Tomatoes

Peas

• Beans
• Carrots
• Chives
• Corn
• Cucumbers
• Mint
• Radishes
• Turnips

Peppers

• Carrots
• Eggplants
• Onions
• Tomatoes

Pole Beans

• Broccoli
• Brussels Sprouts
• Cabbage
• Carrots
• Cauliflower
• Celery
• Chinese Cabbage
• Corn
• Cucumbers
• Eggplant
• Garlic
• Kale
• Kohlrabi
• Peas
• Potatoes
• Radishes
• Strawberries
• Swiss Chard

Potatoes

• Beans
• Broccoli
• Brussels Sprouts
• Cabbage
• Cauliflower
• Chinese Cabbage
• Corn
• Eggplants
• Horseradish
• Kale
• Kohlrabi
• Marigold
• Peas

Pumpkins

• Corn
• Marigold
• Melons
• Nasturtium
• Oregano
• Squash

Radishes

• Beans
• Carrots
• Chervil
• Cucumbers
• Lettuce
• Melons
• Nasturtium
• Peas

Spinach

• Broccoli
• Brussels Sprouts
• Cabbage
• Cauliflower
• Chinese Cabbage
• Kale
• Kohlrabi
• Strawberries

Strawberries

• Beans
• Borage
• Lettuce
• Onions
• Spinach
• Thyme

Summer Squash

• Borage
• Corn
• Marigold
• Melons
• Nasturtium
• Oregano
• Pumpkin

Swiss Chard

• Beans
• Broccoli
• Brussels Sprouts
• Cabbage
• Cauliflower
• Chinese Cabbage
• Kale
• Kohlrabi
• Onions

Tomatoes

• Asparagus
• Basil
• Bee Balm
• Borage
• Carrots
• Celery
• Chives
• Cucumbers
• Mint
• Onions
• Parsley
• Peppers
• Pot Marigold

Turnips

• Peas

Winter Squash

• Borage
• Corn
• Marigold
• Melons
• Nasturtium
• Oregano
• Pumpkin