Marry Your Flowers and Veggies: Companion Planting Guide to Your Garden

By Linda Ly

Gardeners know that a diverse mix of plants, from annuals and perennials to flowers and vegetables, makes for a healthier garden. But did you know that the right (or wrong) combination of certain plants could actually make them more (or less) productive?

The process is known as companion planting. It is believed that growing certain plants in close proximity to others may help deter pests, promote growth and even improve flavor—or on the opposite end of the spectrum, certain plants, when planted close to one another, may actually stunt each other’s growth.

Learn which flowers and veggies work well together, and which ones should be planted far from one another.

What are Companion Plants?

Companion plants are plants that complement one another in terms of growth and production. For example, one plant may attract an insect that might protect a companion plant. Another plant may act as a repellent for a bug that might be harmful to the plant next to it.

It is also important to look at the nutrients individual plants need. A companion plant may need less of one specific nutrient while its neighbor desperately needs it to thrive. In this case, companion planting would eliminate the competition between the two plants.

Benefits of Companion Planting

There are many benefits to companion planting. Most gardeners would agree, the more help you can get to achieve a productive, fruitful garden, the better! What and how can companion planting help?

• Natural Supports – Plants and flowers that grow tall and strong will lend themselves as natural, organic supports to crops that grow low or sprawl. An example of this would be planting tall sunflowers next to cucumbers or snap peas. The sprawling crops can use the taller plants as a trellis.
• Plant Health – Growing plants next to their companions can improve the overall health of both plants. By eliminating competition between plants, you allow one to absorb what it may need without depriving the other. Additionally, as nutrients are pulled from the soil by one plant, the result can actually change the entire biochemistry of the soil. And when done right, the soil can then change or improve the flavor of other plants in the area.
• Optimize Soil – A plant’s root system can easily affect the soil it is in. Plants with long taproots like parsnips and carrots will lift nutrients from the depths of the soil. The nutrients can then benefit those plants with shallow root systems. Nitrogen is also important to many plants, and some, such as peas and beans, actually help to draw nitrogen in, making it more available in the soil for the plants that need it.
• Prevent Weeds – Alternating upright plants and sprawling ones can create a thicker cover across the majority of the open land in your garden area, which will ultimately prevent weeds.
• Regulate Shade & Wind – Too much sun can damage tender and fragile plants. Companion planting can help prevent this by offering shelter as taller plants protect smaller ones. The same is true for wind. The taller and larger plants will offer protection from harsh winds.

Popular Companion Plants for Vegetables

• Dill and Basil – Dill and basil are natural protectants for tomato plants, keeping away the dreaded hornworm.
• Marigolds – One of the best companion plants out there, marigolds help virtually any vegetable. They are particularly helpful for tomatoes, repelling the nematodes that like to attack the roots of vegetables.
• Mint – Mint repels both ants and cabbage moths.
• Nasturtiums – Nasturtiums help prevent insects, particularly aphids, from attacking other plants. Aphids love Nasturtiums and will surround them instead of their neighboring plants.
• Sage – Another helpful herb in the garden, sage can protect from cabbage moths.
• Zinnias – Zinnias are excellent companion plants and attract ladybugs into the garden. Ladybugs are known to control unwanted pests like cabbage flies.

Companion Planting Chart

Type of Vegetable	Friends	Enemies	Special Notes
Asparagus	Basil, carrots, coriander, dill, marigolds, parsley, tomatoes	Garlic, onions, potatoes	Marigolds, parsley and tomatoes protect against asparagus beetles.
Basil	Asparagus, beans, beets, bell peppers, cabbage, chili peppers, eggplant, marigolds, oregano, potatoes, tomatoes	Rue	When basil is grown about 1 foot from tomato plants, it will increase the tomatoes yield. It also improves the flavor of lettuce.
Beans	Beets, carrots, chard, cabbage, corn, cucumbers, peas, radishes	Garlic, onions	Nasturtiums and rosemary deter bean beetles
Beets	Broccoli, Brussels sprouts, bush beans, cabbage, cauliflower, chard, kohlrabi, onions	Charlock, field mustard, pole beans	Pole beans and beets will compete for growth. Composted beet leaves add magnesium to soil when mixed. Magnesium plays an important role in photosynthesis.
Broccoli	Basil, beets, bush beans, carrots, celery, chamomile, cucumber, dill, garlic, lettuce, marigolds, mint, nasturtiums, onions, radishes, rosemary, sage, spinach, Swiss chard, thyme	Asparagus, cantaloupe, climbing beans, mustard, peppers, pumpkins, strawberries, sweet corn, watermelon	Rosemary repels the cabbage fly that is detrimental to broccoli.
Cabbage	Beets, celery, chard, lettuce, spinach, onions	Kohlrabi, tomatoes	Hyssop, mint, and sage deter cabbage moths
Carrots	Beans, lettuce, onions, peas, peppers, tomatoes	Dill	Chives improve flavor, rosemary deters carrot flies
Corn	Climbing beans, cucumber, marjoram, peas, pumpkins, squash, sunflowers, zucchini	Tomatoes	Tomato worms and corn earworms like both plants. Beans and peas supply nitrogen.
Onions	Cabbage, carrots, chard, lettuce, peppers, tomatoes	Beans, peas	Chamomile improves growth and flavor
Potatoes	Basil, beans, celery, corn, garlic, horseradish, lettuce, marigolds, onions, peas, radishes, spinach	Asparagus, broccoli, Brussels sprouts, cabbage, cauliflower, carrots, cucumbers, eggplant, kohlrabi, melons, peppers, raspberries, squash, sunflowers, strawberries, tomatoes	Cucumbers, tomatoes and raspberries attract harmful pests to potatoes. Horseradish increases disease resistance.
Pumpkin	Beans, corn, marigolds, nasturtiums, squash	Potatoes	NONE
Radishes	Beets, cabbage, carrots, chives, cucumbers, kale, lettuce, spinach, squash	Hyssops	Radish plants will work as a trap crop to protect against certain beetles.
Squash	Beans, corn, dill, marigolds, nasturtiums, peas, radishes, strawberries, sunflowers	Potatoes	Squash has similar traits to pumpkin in terms of companion plants.
Strawberries	Bush beans, caraway, chives, lettuce, onions, sage, spinach, squash	Cabbage family, eggplants, peppers, potatoes, tomatoes	NONE
Tomatoes	Asparagus, carrots, celery, onions, parsley, peppers	Corn, dill, kohlrabi, potatoes	Basil, mint, and bee balm improve growth and flavor
Zucchini	Beans, corn, dill, garlic, marigolds, nasturtiums, oregano, peas, radishes, spinach	Potatoes and pumpkin	NONE

Tips for Watering Companion Plants

When growing different varieties of plants side by side, try to group them together by water needs. Deep-rooted vegetables like tomatoes and asparagus should be placed in the same bed, as they will thrive with less frequent (but more thorough) watering that soaks deep into the soil.

On the flip side, shallow- to medium-rooted plants like beans and chard benefit from more frequent watering that saturates just the first few inches of soil. Wind soaker hoses around your plants and attach them to dual outlet electronic timers to easily manage your watering schedule for different beds.

Companion planting is a great way to ensure you have a garden that will grow healthy plants and produce large bounties. A lot of work goes into maintaining a productive garden, so it is worth the time, effort and research it takes to grow like-minded plants that will help each other out. And with Gilmour’s guide to companion planting, we take some of the guesswork out of the process for you!