Tomatoes and summer squash practically epitomize summertime’s bounty. Planting these two summer veggies is a no-brainer since they are both easy to grow and require even less work in the kitchen.
Whether you’re looking forward to the comfort of a ripe tomato sandwich or planning a more elevated ratatouille, there is something extra special about homegrown.
If you plan to grow these two vegetables this season, consider conserving space in your garden by planting them together. Let’s look at how these two crops work together and decide whether it’s a good idea to make companions of tomatoes and squash.
The Quick Answer
Tomatoes and summer squash have very similar environmental needs. While they may not offer stellar benefits to each other, they certainly go well together, and planting them near one another will save time and space. With no known disadvantages, this is a good companionship!
The Detailed Answer
Companion planting is the science and art of planting two or more crops close to each other. This ancient farming method has been used for centuries to maximize symbiotic relationships between crops.
Native Americans used this process often, with one particular combination used so prolifically that it earned the nickname “The Three Sisters.” The sisters are corn, squash, and beans. They were planted together because they all benefit each other in a way that increases the yields of all three crops.
- The corn is a support for the beans to climb on.
- The beans are nitrogen-fixing, so they add nutrients to the soil for the others.
- The squash helps shade the roots and prevent weeds with its large, low leaves.
We can use the same philosophy behind The Three Sisters to create our garden comradeships.
Companion Planting Benefits
When choosing crops to be companions, first consider whether the species benefit each other or do the opposite. Some of the potential benefits of companion planting are:
- Space Saving – Perhaps the most obvious reason to plant crops together is to maximize real estate in your garden. Some plants can be incorporated into underused areas. For example, carrots are great for filling small spaces between other crops.
- Physical Support or Protection – Some crops offer physical benefits to others by providing shade, wind protection, or a place to climb, as in the relationship between corn and beans.
- Scent Masking – Certain herbs and flowers can cover the scent of your vegetable plants, acting as a pest deterrent. Marigolds are good at this, as is rosemary.
- Attracting Pollinators – Species that attract pollinators tend to make excellent companions. Planting some African blue basil or anise hyssop in the middle of your vegetable garden will surely draw pollinators, increasing your yields.
- Soil Improvement – Legumes gradually improve nutrient availability for their neighbors, so you may not need as much fertilizer over time. They draw nitrogen from the air, fixing it in the soil to be used by nearby crops as the legume roots break down.
- Flavor Enhancement – Some crops are known to improve the flavor of others simply by proximity. Basil is reputed to make tomatoes more flavorful in the garden and the kitchen!
Companion Planting Drawbacks
Not all plants make great neighbors, though. Certain crops may not play well with others and prefer to grow independently! Some of the causes of bad companions are:
- Environmental Incompatibility – Not all crops have the same needs regarding water, sun, soil type, and planting season. You wouldn’t plant potatoes with squash because they will compete for space.
- Reduced Yield – Some crops are fertilizer hogs and will rob the soil of nutrients faster than their neighbors can absorb what they need. Nightshades and brassicas are notoriously heavy feeders that need to be fertilized regularly.
- Shared Pests and Diseases – Plants that attract the same pests or are vulnerable to the same diseases do not make good companions. This places them both at a higher risk of destruction. This is one time when you don’t want to kill two birds with one stone.
Tomatoes and Squash Together
So, how do tomatoes pair with zucchini or other types of summer squash, and how well does it stand up to the tests of what makes a good companionship? Let’s take a look at some of the most critical factors.
Season
Both crops are summer-bearing vegetables. They can be planted simultaneously, which means less disruption of their roots.
They both mature at nearly the same rate and continue to produce for several weeks (sometimes months) during the late spring and summer.
Sun Exposure
Squash and tomatoes both like full sun. Both can tolerate a lot of heat and need all that sun to produce the greatest amount of fruits.
Squash has large, low leaves that help shade the ground, which means more moisture is retained in the soil. These broad leaves also maximize photosynthesis beneath the dappled canopy of a tomato plant.
Moisture
Tomatoes need 1”-2” of water per week. They thrive when the soil is kept lightly moist. Watering once daily should be fine in the early weeks, but as the temperature rises and your plants get larger, they may require watering twice daily.
Squash are better at conserving water because their leaves block sunlight from cooking the water right out of the soil. However, they will also be content with consistently moist soil and may reduce the water needed for their tomato neighbors.
Soil
Both plants like fertile, well-drained, loamy soil. They need soil that retains some moisture but doesn’t stay soggy. It would benefit both plants to mix in some organic compost or worm castings before planting to enrich the soil.
Nutrients
Tomatoes are heavy feeders, which means they need to be fertilized regularly. A slow-release, all-purpose fertilizer or Tomato-Tone plant food can promote more plump, juicy tomatoes.
Squash doesn’t need quite the same level of nutrients, but it won’t burn out from the amount of fertilizer a tomato plant needs. The two plants are compatible in this way. Squash is not a pushover, so heavy-feeding tomatoes won’t deprive them as long as you keep it coming.
Space
Squash and tomatoes both need space to spread out but in different directions. Summer squash tends to creep along the ground rather than grow upright.
Most of the foliage on a tomato plant will be above the tops of squash plants, particularly if you trellis them. Tomatoes may cast a bit of shade on your squash, but they should be harmonious nonetheless.
Pollinators
Squash plants produce big, beautiful golden blossoms highly treasured by native bees and honeybees. Commercially, honeybees pollinate most of the squash, but you’ll notice many different bees waist-deep in your squash blossoms if you watch closely.
This is wonderful for tomatoes, which are also pollinated by bees. Tomatoes have less flashy blossoms that the bees can visit even without having squashy neighbors nearby. But the big squash blossoms are a powerful lure for bees, and they will also stick around for tomatoes after they visit the bigger, more prominent blooms.
Adding a borage plant to this combination will increase the number of pollinators even more, as bees love the blue blooms on this herbaceous perennial.
Final Thoughts
Squash and tomatoes match up across the board, making them very good companions. This pairing will appreciate all the same environmental factors, and planting them together will maximize your space. Squash may have more to offer to tomatoes in this pairing, but it doesn’t seem to mind. These plants are great neighbors!
