There’s no question that garlic and tomatoes are a great combo in the kitchen, but do they work well together as garden companions?
Companion planting is the practice of growing certain plants together to create a beneficial, symbiotic relationship – and it’s as old as agriculture itself.
In varying forms, intercropping was embraced by a range of cultures from North American indigenous nations to ancient Chinese and Egyptian farmers and is still practiced around the world today.
Companion planting is one of the best ways to ditch commercial insecticides and enjoy the benefits of organic gardening.
For a pair of garden and kitchen classics like garlic (Allium sativum) and tomatoes (Solanum lycopersicum), it creates a match made in heaven!
Planted together, these favorites thrive in one another’s company.
The pungent A. sativum invigorates the soil and provides pest-repelling properties while the tender tomatoes keep the soil loose and improve drainage, which helps to prevent basal rot in the garlic.
This dynamic duo is an excellent choice for healthy, pest free crops, but care needs to be taken in how and when they’re planted to ensure both crops have the best possible conditions.
Are you ready to learn about this beneficial buddy system? Then let’s dig into the delicious subject of growing garlic and tomatoes as garden companions.
Here’s a quick look at what’s ahead:
Pungent Pest Fighters
Garlic makes an amazing companion to most plants thanks to its pungent aroma and many sulfur compounds.
Compounds like diallyl disulfide and diallyl sulfide have powerful properties that interfere with the sensory receptors of insects and other pests, causing confusion, disorientation, and even death.
These compounds also act as a strong deterrent to the feeding and egg laying habits of many marauding bugs.
Other compounds, like allicin, have a strong odor and also contain antimicrobial and antifungal properties, which help to repel disease-causing pathogens as well as pests.
It’s these compounds that give garlic the well-earned nickname, the stinking rose!
As garlic plants grow, sulfurs accumulate in the soil, acting as natural fungicides that help to protect crops from soil- and airborne pathogens.
And garlic leaf agglutinin (ASAL) is toxic to some pesky sapsuckers, protecting plants from notorious garden raiders like aphids and whiteflies.
Studies have shown that intercropping with A. sativum can help to improve the soil by stabilizing nutrients and pH, which in turn, improves the growth and nutrient content of tomatoes planted nearby.
Pests from aphids and ants to slugs and spider mites are put off by the pungent smell of garlic.
As for bigger critters, deer and voles don’t like the smell either and A. sativum is toxic to rabbits, so they stay away too.
You can learn more about using garlic as pest control here.
And as a bonus, if the scapes of hardneck varieties are allowed to flower, the clusters of tiny lavender, magenta, purple, or white flowers are highly attractive to pollinators like bees.
Clearly there are many benefits to using this fantastic flavor intensive as a companion plant!
Tomatoes have their own beneficial properties as well, keeping the soil loose which improves drainage, helping to prevent bulb rot.
But most of the advantages of this combination are for the tomatoes!
Hardneck or Softneck?
When you’re planning your garden, there is a slight complication as the planting timeline is different for both these species, depending on where you are located.
Hardneck Varieties
In regions with cold winters, the types of bulbs usually sold are the hardneck varieties which have outstanding cold hardiness and can be grown in Zones 2 to 9.
Hardneck varieties have the same delicious flavor, health benefits, and pest-busting properties as braiding or softneck varieties, but they’re planted in fall and harvested from early to midsummer.
This leaves the tomatoes without protection during the crucial fruit set and ripening phases.
Solanum varieties are hot weather plants, and in areas with cold winters, typically aren’t planted out until mid to late spring, depending on winter’s length.
You can intercrop by planting the tomatoes in a bed where garlic is already established, but this can be tricky.
Care needs to be taken to avoid disturbing the existing root systems.
The further away you have to plant the tomatoes, the less beneficial impact the sulfur compounds from the garlic will have.
You can also sacrifice some or all of your hardnecks and bypass harvesting altogether, allowing the scapes to bloom and attract pollinators.
This gives a longer period of protection, but the flavor, texture, and quality of the bulbs diminishes when the plants are allowed to flower or when they’re left in the soil too long.
You can also try to plant hardnecks at the same time as the tomatoes go out, but they don’t generally do well in summer’s heat.
In hot conditions, they falter and struggle, and the stunted growth is less effective at repelling problem insects.
An easy workaround is to use softneck varieties.
Softneck Varieties
Softneck varieties don’t produce stiff flower scapes and the floppy foliage is easily braided for curing and storage.
And because softneck types typically have a better storage life than hardnecks, they’re the ones most readily available in grocery stores.
Softnecks don’t tolerate freezing temperatures as well as hardnecks do, so they are suitable for cultivation in Zones 5 to 9.
Depending on the region, they’re planted in fall, late winter, or spring, then harvested from spring to midsummer.
For all-season protection, you’ll need to sow the softnecks at the same time you plant out the tomatoes.
Since they have better heat tolerance than hardnecks, they can be left in the ground over summer to be harvested later in the growing season.
The bulbs might not grow quite as large as ones that were planted in early spring, but they’ll still have the same amazing flavor and powerful pest repelling properties as early plantings.
The hitch is, if you garden in hardneck territory it can be hard to find softneck bulbs in spring. I look every year, but they’re never available at my local garden stores.
However, they are readily available from many reputable online garden suppliers. Choose from ‘Polish Red,’ ‘Chet’s Italian Red,’ or ‘Nootka Rose,’ among others.
Another option is simply to buy a few softneck bulbs from your grocery store or market to plant out with the tomatoes.
If you go this route, I suggest using only organic produce.
Non-organic bulbs that come from overseas sources have often been treated with chlorpropham (CIPC), an herbicide and growth regulator that inhibits sprouting.
Planting Together
Tomatoes and garlic make great companions, and both enjoy a full sun location with moderate amounts of water.
But when planting, you want to keep an eye on spacing and placement to ensure plants aren’t competing for nutrients, have enough room to grow, and to prevent the taller plants from casting a shadow on the garlic.
To plant out, prepare the garden soil by loosening it to a depth and width of 18 to 24 inches, incorporating enough room for both species.
Mix in a shovelful of compost to enrich the soil plus a shovelful of grit to improve drainage if needed, using materials such as pea gravel or stone chips.
Use a tablespoon of bone meal per plant to give the roots a strong, healthy start and improve bud set.
Plant and space S. lycopersicum as outlined in our guide to growing tomatoes.
If growing indeterminate varieties, set cages or stakes in place for each plant as needed.
Grow the A. sativum on the south side of the bed or in front of the tomato plants to ensure they receive full sun.
Plant out as per our garlic growing guide and space the cloves six inches apart and six to 12 inches in front of the toms.
In areas with very hot summers, you can orient the garlic to the west or southwest so they’ll receive some light afternoon shade cast by the taller plants as the sun travels.
After that, water, fertilize, and mulch the combined plants as you would for individual crops.
If you like to grow your tomatoes in containers, simply pop two to four cloves six to 12 inches in front of the toms when planting, placing them on the sunny side of the container.
Beneficial Buddies
Planting garlic and tomatoes together as companion plants is a smart and easy way to keep pesky pests at a minimum.
Locate the cloves at the front of the tomatoes so they get full sun or give them a western orientation for some light afternoon shade.
This companion planting system gives excellent protection for your Solanum plants, and planting softneck varieties at the same time is the best way to give them potent cover for the entire growing season.
What types of garlic do you folks use for interplanting with tomatoes? Let us know in the comments section below.
And for more information about growing garlic in your garden, check out these guides next:
