What is the Best Spacing for Garlic Planting?

You know I’m always looking for ways to improve my garlic harvest. What exactly do they need to grow to their fullest potential?

And as soon as the days start to get shorter, my thoughts turn to the upcoming garlic season and creating the perfect environment for my garlic babies.

So, as I was planting my garlic cloves last fall, it got me wondering: could there be a better spacing option for growing garlic?

To answer this question, I ran a garlic spacing experiment and discovered some REALLY interesting results! Today, I’m going to take you through my exact method and SURPRISING learnings from this experiment.

Why is garlic spacing important?

When it comes to growing garlic, each bulb needs enough room to grow and to access nutrients. You also want to maximize the space you have available in your garden. 

Squeeze the cloves too close together, and you’ll end up with underdeveloped bulbs; space them too far apart, and your harvest could be too small!

For background context, 6-inch is the traditional spacing for planting garlic and served as our control for this experiment. 

BUT, is this really the best spacing for garlic size and yield? 

(Hint: I may have discovered a better garlic spacing option!)

Garlic spacing experiment: 6-inch vs. 6-inch off-centre

Last year, I ran an experiment comparing 6-inch spacing with 6-inch off-centre spacing.

In that experiment, the garlic planted at 6-inch intervals had an average weight of 52 grams per head, whereas the garlic planted at 6-inch off-centre spacing had an average weight of only 41 grams per head.

Now, here’s where it gets really interesting: I was able to plant additional rows with the off-centre spacing. So, while the average garlic bulb size was a little smaller, the total yield told a different story. The total harvest from the 6-inch spacing was 4.056 kilograms while the total harvest from 6-inch off-centre spacing was 5.658 kilograms!

For that reason, this time I opted for a 7-inch off-centre spacing to see if a bit of extra room would help the garlic bulbs grow just as large as those with the traditional 6-inch spacing — I am excited to share the results with you today!

Garlic spacing experiment: 6-inch vs. 7-inch off-centre

In October, I took a piece of string and ran it right down the middle of my raised bed to split it in half. This allowed me to have two identical environments where I could test two garlic spacing options

• Step one - 6-inch spacing: On the right side of the bed, I used my Hori Hori knife to make a transplant hole every 6 inches in a grid formation.

• Step two - 7-inch off-centre spacing: On the left side, I made a transplant hole every 7 inches and then went and made an additional hole in the centre of the rows, meaning that each garlic clove has around 3.5 inches between them.

Once I had the two sides spaced out, I then prepared and planted all the garlic cloves the exact same way: 

• Step three: I put about one handful of worm castings into each hole to ensure the garlic had all the nutrients and microbes needed to develop roots over winter.
• Step four: I planted one Red Russian garlic clove into each transplant hole with the pointed tip facing up.
• Step five: I covered the bed with 3-4 inches of leaf mulch to help protect the garlic from the coldest temperatures over winter.

Now let’s fast-forward to early March, by which time the garlic plants were already 4-5 inches tall:

• Step six: I removed the leaf mulch to be able to give them a big feed for springtime.
• Step seven: I applied 1 tablespoon of 444 Superfood organic fertilizer per square foot, around the base of each garlic shoot. I also added a 1-inch thick layer of compost to the bed, providing insulation as well as a lot of nutrients and microbes for the garlic to put to use over the following months.

PS- If you’re thinking of growing garlic this upcoming season, we’ve got a really cool Garlic Kit that has everything you need to grow big and beautiful garlic!

From here, I allowed the garlic plants to grow until June, at which point the garlic scapes emerged:

• Step eight: I removed all the scapes from the garlic to make sure the plant’s energy was directed to developing the garlic bulbs beneath the surface.

So in mid-July, after nine months of hard work, it was time to start harvesting!

PS- If you’re interested in growing your own delicious garlic crop, make sure to check out my garlic growing MASTERCLASS, which has everything you need to know from planting the garlic cloves all the way through to harvest!

6-inch vs. 7-inch off-centre spacing SURPRISING results

After letting the harvested garlic dry for 14 days, I went ahead and removed all the necks, roots, and outer layers, leaving just the heads ready to be measured.

Getting started with the 6-inch traditional spacing, the total weight came up to 1.464 kilograms across 37 heads of garlic. This makes an average weight of 39.56 grams per head.

For the 7-inch off-centre spacing, the total weight came to 2.300 kilograms across 53 heads of garlic. This makes an average weight of 43.39 grams per head!

So, not only did the 7-inch off-centre spacing produce a larger total yield, but the garlic heads were actually LARGER than the 6-inch traditional spacing! 

What’s the best spacing for garlic planting?

As we know, there's no one-size-fits-all method in gardening, but this experiment has given us some really interesting learnings! While both options grew well, it turns out that 7-inch off-centre spacing might just be the secret to big garlic bulbs AND larger harvests.