How to Easily Build an Herb Spiral Garden

If you stopped by my garden for a visit one day and I gave you a tour of the front yard you’d likely stop, point and ask, “What’s that?”

“Oh, that’s my herb spiral!”, I’d reply.

And then you’d start asking me how I built it. (And I’d be happy to share!)

This scene plays out over and over again in my garden each year when friends, family, and neighbors get my two cent tour. My herb spiral is a conversation piece!

I decided to build it when I was expanding my front yard garden and was worried that too many square and rectangular beds would make the garden feel too linear.

Around that time I was reading The Vegetable Gardener’s Guide to Permaculture: Creating an Edible Ecosystem, which is packed with simple projects for the home gardener. An herb spiral was one of the things that caught my eye in the book and I thought it would be a perfect way to add a softer and more organic shape to my front yard garden.

Several years later it remains one of my most favorite things I’ve ever built in my garden (along with these easy DIY trellises) and it was so easy! You don’t need any special tools, talent, or know-how to build one in your own garden.

In fact, after teaching my herb workshop throughout the winter to garden clubs and Master Gardener groups, where I show people how to build their own herb spiral, I often get a few emails in the spring from people who’ve taken on the project and built one themselves after being inspired by my class.

Here’s a quick overview on how to build an herb spiral, including a fun time-lapse video filmed by a PBS show that visited my garden while I was constructing mine.

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Why You Should Build an Herb Spiral

First, let’s talk about the reasons why you might want to build an herb spiral.

Compact. You probably already know that growing up is an efficient way to fit more food in the same space in your garden. Besides growing plants on trellises and arbors, using an herb spiral, depending on its design, can help you grow more herbs in a smaller space.

Water drains naturally. Many of the common herbs like sage, thyme, and rosemary originated in warm and dry Mediterranean climates. This means that they aren’t going to be happy in wet conditions. Because an herb spiral is elevated, it will shed water and keep those herbs happy and healthy.

Retains heat. Many herb spirals are made from bricks or stones. Their solid mass collects heat from the sun during the day and then release it all night long. This is great for northern gardens like mine, which often see cooler nighttime temperatures. I find that my heat-loving herbs grow like gangbusters in the herb spiral.

Adds structure and interest. Our vegetable gardens can easily turn into very linear environments with square and rectangular beds planted with straight rows of vegetables. Nature features lots of soft and rounded shapes, so why not include some in your vegetable garden design?

How to Build an Herb Spiral

Building an herb spiral is very easy – I promise! I walk you through the step by step process and in no time you’ll be out in your garden constructing your own.

Step 1: Design

The first step of building an herb spiral is deciding on your design. I highly recommend using Pinterest for this research step. You can use it as a search engine and type in “herb spiral” to see lots of different designs and materials people have used to build theirs. 

After looking around for a while I was most interested in building one made out of bricks, so that’s what I chose for my design inspiration.

Step 2: Location + Size

Next, you’ll want to decide on the location and size of your spiral. Pick a flat spot in your yard or clear an area to make it level. I wanted to incorporate my herb spiral into my garden expansion, so I situated it between two curved, rectangular garden beds.

Herbs prefer full sun (at least 8 hours/day) but will grow with less. Ideally you’re situating your herb spiral in the sunniest location possible.

You can make your herb spiral any size you’d like. It really depends upon how much space you have and what fits with your overall garden design. Oh, and how many herbs you want to pack in there!

My herb spiral is 5 feet wide and 20 inches high. I used about 120 bricks. Make sure you have about 8 inches wide of planting space to give the plants room to grow.

Step 3: Gather Materials

You should be able to find most of the materials you’ll need for an herb spiral from a local landscape supply or home improvement store. Here’s what you’ll need.

Building Materials for the Spiral
Most herb spirals are commonly made out of bricks, landscape pavers, or some kind of round or flat stone. 

To purchase the bricks for my spiral, I went to a local reuse store and loaded up my little hatchback with a pile of bricks taken from a 100 year old building. I wasn’t sure exactly how many I needed, so I just bought about 80 bricks. I did end up needing to go back for another small load to complete my spiral.

I’m more of a wing it kind of person, but if you like to calculate things ahead of time you can make an outline of your spiral with the steps below, measure the building blocks you’re using, and then try to calculate how many you would need.

Soil
You’ll need to fill the spiral with soil once you’re finished building it. I was building other beds in my garden, so I already ordered a bulk delivery of 1/2 topsoil and 1/2 compost. I don’t recommend filling the spiral with straight compost (been there, done that!) because it likely won’t have enough nutrients for healthy plants. I like a mixture of soil and compost instead.

I’ve build lots of gardens throughout the years and I’ve found that when I order soil to fill garden beds it’s often of poor quality and lacking in nutrients.  Most herbs are more forgiving of less than ideal garden soil, but I still recommend adding an organic fertilizer before planting. Read about which kinds of organic fertilizer I recommend.

Plants
After you’re finished constructing your herb spiral it will be ready to plant! You can grow pretty much any herb in your spiral. We’ll talk more about what to grow further along in the article.

Mulch
If you leave bare soil in your garden it will be susceptible to compaction, erosion and weed growth. This is why I don’t leave soil uncovered in my garden unless I’m waiting for seeds to germinate.

Most of my garden beds are mulched with oat straw or hay mulch, but I like something a little special for my herb spiral. I purchased a big bag of cocoa bean hull mulch a few years ago and only use it on the spiral. It smells divine right after you apply it to the garden!

I’ve also used composted leaves or partially broken down compost. There’s no reason you can’t use hay or straw, I just like using a darker color mulch on this bed.

You can read a lot more about mulch, which I’m a fanatic about, in this post: Why Mulch is the Ultimate Garden Tool.

Tools
To actually build the spiral and move soil you may need the following tools:

Tamper to level the ground if necessary

Rake

Shovel

Wheelbarrow

To plant the seeds and plants you’ll need:

Trowel (the best one ever!)

Watering Can

Organic Fertilizer

Step 4: Start Building!

Trace the outline of your herb spiral on the ground using a stick or other sharp object. Keep fiddling with it until you’re happy with how it looks.

Start laying your first course (that’s what each layer of stone is called). Take the time to get a shape you like. I used some of the less shapely bricks on the bottom since I figured they’d be mostly hidden.

When you get your first bottom course completed, you’ll start the second course by coming back to the beginning and counting in 2 1/2 bricks. You’ll start your second course at this point. See the photo below and accompanying video for more explanation.

You’re going to continue to repeat this with every layer until you run out of bricks or get the spiral to your desired height. When starting each new course, count in 2 1/2 bricks and then start laying. There’s no right or wrong here, it’s all about how you want it to look.

Step 6: Add Soil

After your infrastructure is finished, it’s time to add soil. As you learned above, I prefer a mix of half organic compost and half topsoil. If you ordered a bulk delivery, use a shovel and wheelbarrow to fill your herb spiral with soil. 

The soil will settle a few inches over time, so don’t be afraid to really top it off!

It’s not a good idea to leave bare soil in your garden because it will grow weeds and get eroded and compacted by rain and wind. After filling, you should mulch the soil in your spiral with hay, leaves, straw, or grass clippings. You can see in the below photo I used leaves.

Step 7: Plant Herbs

If it’s fall, simply mulch your spiral well to protect it over the winter and have fun dreaming about all of the fun things you’re going to plant the following spring!

If you’ve built your spiral in the spring you can start planting your herbs right away. I recommend taking a trip to your local farmers market for seedlings. For most herbs you’ll only need one or two plants since they produce a lot. That’s why I recommend purchasing plants instead of seeds.

The only herbs I plant by seed in my garden are cilantro and dill and I usually plant them in another garden bed since I like to grow large amount of of them.

You can grow pretty much any herb you want in your spiral. I have a mix of perennial herbs like thyme and mint that stay in the same place from year to year and then I intersperse annual herbs like lavender, calendula, basil, and parsley. It’s fun to change up the design every season with different combinations!

Here’s a list of what I’ve planted in my herb spiral over the years:

Basil

Lavender

Lemongrass

Mint (highly invasive!)

Onion Chives

Oregano

Parsley

Rosemary

Sage

Thyme

Maintaining Your Herb Spiral

I’ve found there’s not much maintenance involved with the herb spiral. I keep it weeded and make sure to harvest the herbs on a regular basis. I mulch once a year and have added a little bit of soil to the top as its settled over the years.

Depending on where you live, most of the perennial herbs should come back each year so you won’t have to replant. If you use annual herbs like parsley or basil you’ll have to purchase new plants each season.

You can also trim back dead parts of the herb plants in spring if you notice any.

Building an herb spiral is a simple project you can tackle any time of year! I hope this post proved to you that it doesn’t take any special tools, talents, or know-how to easily create an awesome spiral. Believe me, any gardener can do it!

And after you do, you’ll be rewarded with a dramatic focal point that will be the talk of your gardener friends!

Additional Resources for Building An Herb Spiral + Growing Herbs

VIDEOS OF ME BUILDING MY HERB SPIRAL

You can watch the video that accompanies this post for a more in depth look into how I built my herb spiral.

While I was building my herb spiral a few years ago the PBS show, Victory Garden/Edible FEAST came for a visit to my garden. They shot a cool time-lapse video of the process and also invited me to talk about using row cover to extend the fall harvest season. My segment starts at minute 13 here.