Can garlic protect herbs and vegetables from pests and diseases?

This is a follow-up post on the article I wrote on garlic as a companion plant a while back. And for me, garlic is one of my go-to vegetables to grow for consumption while bringing pest-fighting benefits to my garden.

This article will summarize my findings and experiences from last year, outline my plan for this coming season, and give you actionable advice in your fight against pests and diseases.

So, did garlic help deter pests and diseases last year?

Last year was an excellent garlic year. My plants thrived through winter and even brushed off a heavy snowfall in late March.

This was last year, though we also had snowfall in March this year.

I planted most of my bulb garlic in two separate raised garden beds. I planted some cloves randomly amongst my herbs and around my wife’s roses. Refer to our article on growing garlic if you need an easy-to-follow guide.

Apart from planting cloves for bulbs, I like to grow garlic greens in water. As my garlic greens grow in a contained space like a regular glass or jar, I use organic store-bought garlic bulbs whenever I find them at a reasonable price. Where I live, it is hard to find good quality seed garlic at a fair price come early spring. 
Garlic is cold hardy, here garlic growing through snow in March
Yes, we did get snow in March this year as well

And the results were an excellent year for tomatoes, squash, dill, kale, and Swiss chard. I hardly suffered any problems with aphids, slugs, stink bugs, squash bugs, leaf miners, or fungal diseases. 

Was it all thanks to the garlic? That’s the thing about companion planting. The findings are subjective and anecdotal. But for me, the results and benefits are clear and convincing. I will continue to use garlic to deter pests and diseases in my herb and vegetable gardens.

But this year, I will use garlic in a slightly different way.

Using garlic to protect against pests version 2.0

Why differently if it was successful? Well, in short, I can get more mileage from each plant if I distribute the garlic plants across more planting boxes.

A somewhat straight row of garlic border plants
A somewhat straight line of garlic border plants

The plan is simple. 

  1. Garlic grows tall; make sure it does not shade plants unnecessarily
  2. Ensure I only plant garlic where I think it will help
  3. Remember that garlic does like full sun to thrive

My only mistake last year was that some of my garlic plants cast a shade on the area where I usually put my cherry tomato plants. It was not a massive problem as I grew most of my cherry tomatoes in pots and containers. Still, it did force me to re-do my garden plan on the fly, and I ended up with lots of pots, grow bags, and containers in an area usually reserved for leafy greens.

Solution? This year I am planting my garlic cloves at the far end of the garden beds. This way, garlic plants can grow tall without shading any other plants. 

The area will still get a lot of sunlight and should help protect more plants than last year.

What about the plants growing at the other end of the garden bed?

By default, the plants growing closer to the garlic should receive more benefits from the pest-protecting qualities of garlic. There is no way to eliminate this. 

But here, my garden plan springs into action. Many herbs, like basil, chives, mint, and thyme, offer pest-fighting properties. Thyme, for example, is a favorite to deter whiteflies, cabbage loopers, and tomato hornworms. These herbs will grow on the opposite side of the garden bed.

I will also use lavender as a border plant and let some thyme plants bloom at the far end, as it will attract pollinators that double as predators against harmful bugs and insects. 

I do like my plan.

Pollinators will often feast on unwanted pests and insects as the predators they are
Pollinator on blossoming thyme plant

One more development to my organic pest-fighting arsenal is a fantastic place to learn and share knowledge as a gardener. And this year, I will use a tip from Dave and Trish. 

I will blend garlic with my Bhut Jolokia ghost peppers (or another hot pepper like habaneros) and aromatic herbs like basil or sage. Strain the mixture into a container and add water to get my pest-fighting mix. Using a spray bottle, I will mist my plants early morning or evening to deter those nasty bugs and insects that so like to feast on my plants.

I will update you on the results next year. But I am confident it will work wonders.

Mattias Magnusson: Hello, I'm Mattias, a passionate and experienced gardening enthusiast. I am the creator of, your guide to year-round herb and veggie growing. Let's simplify green living, no matter your space or location.