Companion Planting: A Simple Vegetable Garden

Written By Melissa Guzowski

Hey all! I am writing a simple garden guide on how to grow the most common vegetables. If you have a small garden in your backyard, this article will provide you with a guide on how to companion plant your herbs and vegetables to encourage growth, prevent plants competing for nutrients, keep pests away and avoid pre-mature bolting.

I am a huge advocate of a permaculture style garden. Creating a healthy growing environment where plants aide each other and create an environment of permanent agriculture that will not only out live you, but also demand less work of you while you maintain it and benefit from its fruitful prosper. Companion planting is a great start to creating that kind of environment, as is no digging up and closing your garden at the end of the year! Many of your plants will reseed themselves, saving you money on seeds and starts for the next season. I have annual plants that I let go to seed and self seed in my garden the next year, coming back stronger than the year before with absolutely no work on my part, outside of maintaining it while it grows and picking the flowers and fruits it provides for me.

All of the plants in this article can be started from seed before gardening season if you are all in and commit to seed starting trays in February/March (except lettuce which can be seeded at any time throughout the season for baby greens.) But, especially for our beginner gardeners these 7 plants listed below do best started early, so you want to buy starts (or already started plants) that are strong and developed by the time gardening season begins in Spring. Tomato, Eggplant and Pepper plants all take time to develop and mature before they are ready to produce fruits. If you plant them from seed in your garden in the spring, your growing season will be drastically shortened by the time the plant takes to develop. You want starts for plants like this that have been started in February so they are ready to produce by the time they are transplanted into your garden.

Why Companion Plant?

There are many reasons why we should all companion plant in our home gardens. Some plants attract the same pests and should not be planted together to avoid an infestation. Some plants suffer from the same ailments and should be kept apart to avoid a widespread infection that will call both plants as it spreads throughout the soil, leaving you with a dead garden and infected soil that will need to be replaced the following season. Some plants will stunt each others growth, leaving you will no fruit and sad plants that go straight to seed and then die off. Some plants compete for the same nutrients from the soil, so you want to keep them apart. Companion planting teaches us to grow plants that replenish nutrients next to plants that require them. Some plants just don’t like each other, just like people. Our plants have friends in the garden, and learning about their companions will help you big time in the long season of gardening and a deeper understanding of how to keep your plants happy, healthy and fruitful.

1. Tomato

Tomatoes are not the most commonly grown home garden plant for no reason, it is because they are so easy to grow. While they are so easy to grow and prosper despite how much effort put in, I can’t tell you how many times I see people grow tomatoes hoping for a big bushy, leafy plant. Tomato is a VINE! This plant only needs its upper most leaves to photosynthesize- the lower leaves, although they make our plant look bushy and full, are a waste of the plants energy if you are looking for a large fruit production. Pick off your lower leaves. Tie your vine to a stake or trellis. A friend taught me to do it with old pantyhose as it doesn’t damage the plant and it works like a charm. Watch your fruit prosper. Pick off the shoots that sprout from in between leaflets and vine when they are small to encourage fruit production and a single tall, stalky vine instead of a bush. Keep a regular watering schedule to avoid your fruit splitting.

Add Epsom Salt to your watering schedule once a week to aid your plants growth and fruit health. Tomatoes are one of the most ‘social’ garden plants. They have a ton of companions that aide their growth, improve their flavor and love to grow alongside! It also has a few plants it does not like to be planted with. For example: Tomatoes and Potatoes both are prone to blight which will kill your plants. The blight can spread through the soil from plant to plant. Most Tomatoes will die from blight by the end of a season, so delaying this as long as possible is through maintenance and picking off leaves that look infected, since as we said before we don’t need the lower leaves anyway this will not hurt your plant to prune it. Don’t be afraid to prune your plants! So many are afraid to do this, but it is beneficial to your plants in the long run.

Let’s talk about the things that benefit our tomato plants and the reasons why. Tomatoes and basil aren’t planted together for no reason, yes we love to eat them together, but they also love to grow together! Basil improves the flavor of your tomatoes and it also promotes the plants growth. Plant your basil next to your tomatoes every. single. time. Planting garlic near your tomatoes helps repel spider mites from your tomato plants. Planting carrots between your tomato plants creates space in the soil for water and air to get to your tomato plants roots, which they love. Planting borage near your tomato plants deters tomato horn worm, which is a common tomato plant pest (and borage flowers are edible and attract pollinators!) Oregano is a socialite of the garden and improves the growth of anything planting near it. Growing chives near your tomatoes improves the flavor of your tomatoes. Asparagus and tomato also love each other and are best friends in the garden, plant your perennial asparagus crown in an area next to where you will always grow your tomatoes and watch they flourish together- they benefit each other reciprocally. Nasturtium near your tomatoes repels garden pests and attracts pollinators (Nasturtium is the most underrated garden plant in my personal opinion, the leaves are spicy and edible, similar to arugula, and the flowers are edible, peppery and gorgeous!)

I could clearly talk about tomatoes forever, but let’s move on.

Plant With: Basil, Chives, Oregano, Parsley, Borage, Marigold, Nasturtium, Peppers, Asparagus, Carrots, Beans, Garlic, Celery, Lettuce, Onions

Keep Away From: Dill, Corn, Potatoes

2. Cucumber

The first thing I want to say about cucumbers is that they are climbers. Do yourself and your cucumbers a favor and give them a trellis to climb on. I like a bridge style trellis and I plant my cucumber plants in a row that is parallel to the trellis to they can climb all the way over to the other side, but can hang from the arch for airflow. I avoid letting my viney vegetables sit on the ground to rot on the soil if I can prevent it. Cucumbers like space and air to thrive. You can plant cucumbers under your corn or sunflower plants to use those tall plants as a natural trellis for your cucumbers as well!

For those who don’t know or haven’t yet grown cucumbers at home: they’re prickly.

I wrote about this garden pair in 10 Garden Pairs That Are Meant For Each Other, but cucumbers and radishes truly belong together. Radish repels cucumber beetle and cucumber improves radish growth, so they are a mutually beneficial garden pair.

Dill is also an incredible companion for cucumber as it attracts predatory insects to pollinate your cucumber flowers (and is one of the few things dill can be planted alongside). Nasturtium improves the flavor and growth of your cucumbers, and is a fun edible (both leaves & flowers) to add to your garden, deter pests, attract pollinators and bulk up your salad green growth. I love to make a vinegar from Nasturtium flowers, which I will be posting a link for soon.

Things you want to keep away from your cucumbers are potatoes and sage. Cucumbers and sage do not like growing next to each other. Potatoes and cucumbers compete for the same nutrients from the soil so you also want to keep those plants away from each other so they both have access to the amount of nutrients they require to thrive.

That last key to growing healthy cucumbers that thrive in a long growing season is by delaying the onset of powdery mildew on your cucumbers leaves. If you have grown cucumbers you have certainly seen powdery mildew before. Powdery mildew grows on cucumber and squash leaves, and it will kill your plant if you let it. Luckily, there are ways to keep it at bay. Water feeds the mildew so keeping your leaves and stems dry will work to your advantage. When watering your cucumber plant. Try to lay your hose on the ground to just water the soil and roots- avoid getting water on your above ground plant material if you can help it. The more you can avoid it, the happier your cucumber will be. Sometimes it is unavoidable, but it is something to be aware of.

Plant With: Radish, Beans, Cabbage, Corn, Asparagus, Brassicas, Celery, Dill, Kohlrabi, Lettuce, Onion, Peas, Sunflowers. Nasturtium, Borage

Keep Away From: Potatoes, Sage

3. Squash

Same watering rule applies to squash. Squash leaves are also prone to powdery mildew, so you want to avoid getting water on the above ground plant parts as often as you possibly can. When you do see powdery mildew on your squash plants, cut off the leaf and stem ASAP. It will spread like wildlife on your squash plants. Squash is similar to tomato in that it LOVES to be pruned and only needs its uppermost leaves to photosynthesize. This means leaving the newest growth at the top and picking off the rest of your squash leaves, especially when they have any sign of mildew. This refocusing the plants energy on producing ‘fruit’ instead of growing foliage (leaves).

Water your squash by putting the hose on the ground to just water the roots and soil. This will also help prevent rot, maggots or unwanted pests inhabiting your squash stems.

Companions: Borage is an incredible companion for squash. Borage improves the flavor of squash and improves the plants growth.

I always keep these close in my garden. Borage also produces edible flowers which I’m sure I've already mentioned previously but it is beneficial for you as much as it is for our dear pollinators we’d like to draw into the garden. Nasturtium, as I’ve probably mentioned a million times throughout this article already, is a great companion for squash and repels unwanted pests. Marigold does the same and is a great companion for squash as well.

Now, let’s focus on our squash flowers. Squash flowers are a gem of the garden, so let’s talk about how to identify the difference between male flowers (what you should pick) vs. female flowers (which you should let grow into squash). I chose the picture displayed above because it shows us a great example of both types of flowers. You can see in the picture above what a female flower looks like when it is small and then a larger example of how the flower dies off at the end of the zucchini as the vegetable grows larger in size. You can identify a female flower by the baby squash grow is growing attached to it instead of a stem. You want to let these grow into squash for you to pick, eat and be merry. Male flowers look different. Male flowers will not produce a squash. These are meant to be picked, stuffed and eaten. I love to stuff mine with goat cheese and fry them. There is an example of a male flower in the above picture that is closed but about to bloom. It is tall, leggy and only contains a flower attached to a thin, hollow stem. Wait for these flowers to bloom, attract pollinators and then pick pick pick! One of my personal favorites. Take our the pistol at the base on the inside of the flower, and them eat the whole thing! An edible & floral delicacy.

Plant With: Borage, Marigold, Nasturtium, Corn, Lettuce, Melons, Peas, Radish

Keep Away From: Brassicas, Potatoes

4. Eggplant

Just like tomatoes, eggplant loves to grow alongside basil. Basil helps promote growth for most of the nightshade family, so eggplants are no exception to this. Boost your eggplants growth by planting a little basil in its shade.

Eggplants also love to be planting next to the nitrogen fixing legume family! This includes everything from beans to peas and there are lots of options to companion plant with in this family. Bush beans are a favorite companion of eggplant because they not only fix the nitrogen in the soil but they repel Colorado potato beetle as well, which may pray on your eggplant. I find that Japanese Eggplant produces more than larger varieties (usually produce 5-6 eggplants).

Usually I have one of each variety in my garden, so just keep that in mind if you grow the larger varieties, you will have them few and far between with only one plant. You can grow multiple or switch up varieties to have a higher yield.

The only thing you have to worry about definitively keeping away from your eggplant is fennel, which is no surprise because nothing in the garden likes growing near fennel, it is a lone star. While our eggplants are flexible, they do still have preferences in regard to their garden companions.

Plant With: Peas, Beans, Bush Beans*, Basil, Amaranth, Marigolds, Peppers, Spinach, Thyme

Keep Away From: Fennel

5. Peppers

Growing peppers is very similar to growing tomatoes. If you can grow one, you can surely grow the other. In fact, growing peppers is probably easier than growing tomatoes, as peppers don’t even need pruning to thrive. There are so many varieties of peppers to grow outside of the common bell peppers which can take a long time to ripen. My favorite varieties of peppers to grow are Shishito, Jimmy Nardello, Banana, Jalapeño and Cayenne. These plants produce high quantity and mature much faster.

Like most nightshades, basil is a number one companion. Basil promotes the growth of peppers, so keep in mind to keep them close.

To improve the flavor of your peppers, companion plant with carrots and/or onions- both of these plants love to be planted with your peppers and will contribute to its flavor profile! This also works well when you are short on space as peppers grow up, while carrots and onions grow down- maximizing the use of your garden space.

Peppers and tomatoes also grow well alongside each other so I usually will plant a row of tomatoes in the back with stakes, a row of basil in the middle and a row of peppers in front to let both plants benefit from the basil as a companion. Parsley, Onions, Asparagus, Carrots, Eggplants, Cucumbers, Oregano or Eggplant are all plants that are happy to be thrown into the mix within this little garden community of companions.

If you have the option, water your peppers at night instead of the mornings. If you water them during the heat of the day, they may never forgive you as you will scorch the leaves with sunburn (a very dear farmer friend of mine taught me that trick!) If you’re growing spicy peppers, let them run on the drier side to increase the spice level. That’s it! Peppers are easy enough. Pick your peck of peppers and enjoy the sunshine with this low maintenance plant.

Plant With: Tomatoes, Carrots, Okra, Asparagus, Onions, Eggplants, Basil, Cucumbers, Endive, Oregano, Parsley, Rosemary, Squash, Swiss Chard

Keep Away From: Beans, Brassicas, Fennel

6. Lettuce

Lettuce is a fun, easy and replenishing garden green. There are a ton of different varieties and tons of blended seed packs to keep your salads fresh and obtainable all summer long. A common mistake gardeners make: planting lettuce in direct sun. Your lettuce likes shade, it will have a much longer growing season in the shade and it grows best in early spring or in the fall. It does not love the dead heat of mid-summer, and will most likely prematurely bolt due to the heat. Bolting- for people who aren’t familiar with the term is when the lettuce shoots up flower stalks. This is an effort to produce seed and happens when the plant is trying to spread it seed and then die off.

Once your lettuce has bolted, its leaves are no longer ‘choice’ or ideal for eating. They become tough and bitter. You want to avoid your lettuce from prematurely bolting, and you want to delay it from bolting by keeping it cool, wet, and shaded to prolong your growing season. There are many ways to keep your lettuce cool and shaded if you would like to grow it through the heat of summer.

Planting you lettuce on the porch in the shade in pots is an option. Planting lettuce under sunflowers, tomatoes or pole beans is a natural way to use your garden resources and provide shade for your lettuce under taller crops. Building a small tent or buying one (there are plenty of options out there for lettuce shade products) can also keep your lettuce out of direct sunlight.

One suggestion I will make if you’d like to have a constant supply of lettuce in your garden all summer long is to only pick the leaves instead of digging up the whole head of lettuce, as they will grow back, and plant lettuce seed every 2 weeks as you pick it to keep a fresh supply coming in.

Another cause of premature bolting is planting parsley near your lettuce. Parsley and lettuce do not co-exist well. Parsley causes your lettuce to prematurely bolt, so you want to make sure you keep these two plants far apart in your garden.

Although lettuce has needs to thrive, it is a very social garden companion! Making sure to keep it away from parsley is priority, but there are many plants that love to grow alongside lettuce. Lettuce tenderizes radishes, so planting radish among you lettuce not only benefits your radishes, but radish greens are also edible and delicious so no harm if you mix the tops in with your greens! I love to plant cilantro with my lettuce as they grow well together. I also usually plant beets and radishes with my lettuce as well as both tops are edible and can be added to salad blends and contribute different nutrients to your fresh salad greens! Strawberries are also a friend of lettuce, cucumbers, spinach and carrots are all great companions for your lettuce.

Plant With: Cilantro, Sunflowers, Tomatoes,  Pole Beans, Beets, Carrots, Parsnips, Radishes, Brassicas, Celery, Chervil, Cucumbers, Dill, Garlic, Onions, Spinach, Squash, Strawberries

Keep Away From: Parsley

7. Strawberry

The first thing you need to know about Strawberries is that they love to be planted with chives. Chives fight off disease and keep your strawberries plants happy and healthy. This is a beneficial partnership in more ways than one, as these are both perennial plants, they will come back stronger, larger and healthier every year and benefit from their partnership. Strawberries enjoy being planted with any member of the Allium (Onion/Garlic) Family happily- so feel free to plant them next to your onions, garlic, chives or scallions. Strawberries also do very well with the legume (Peas/Beans) family, BUT the legume family and the allium family do not get along. You have to pick which you’d plant with.

As alliums benefit the strawberry plant more, that is my recommendation and my personal choice for companion planting my strawberries.

The second thing you need to know about strawberries is that they love air flow.

Strawberries are a great plant for hanging pots or planters, so the fruits have air flow. Strawberry fruits are heavy and weigh down the rest of the plant, if you don’t hang them for the fruits to be suspended, your fruits will rot on the ground in the soil they are bound to sit on. Give your strawberries the gift of space and suspension, and put them in pots so the fruits can hang off the edges or hang them in the air and use gravity as your friend.

Strawberries also enjoy being planted with lettuce, spinach and borage. If you have a pot where you grow your salad greens, don’t be afraid to throw strawberries into the mix. Borage is a plant that grows edible flowers you can eat, candy and use as a garnish. They’re gorgeous and they bring pollinators in abundance, making them a great buddy for your strawberries as you need pollinators to turn your strawberry flowers into fruits! Plant gorgeous flowers that you can also eat. Nothing makes my heart glow brighter than eating a flower.

PSA: Strawberry leaves are medicinal! Dry them out. Make tea. Thank me late. Use your plants. Don’t just eat what the grocery store tells you. Learn your garden. Reap all of its benefits, safely and knowledgeably.

Plant With: Chives, Beans, Borage, Garlic, Lettuce, Onions, Peas, Spinach, Thyme

Keep Away From: Brassicas, Fennel, Kohlrabi