How to Make an Herb Spiral

Imagine a garden design that offers an ingenious way to cultivate a variety of herbs while maximizing space and reducing maintenance. Enter the herb spiral, a sustainable and accessible gardening concept that has captured the imagination of garden enthusiasts. They are like mini herb gardens that you can build in a small space, and they have some unique benefits for gardening. We’re going to give you a step-by-step guide that will show you how to make an herb spiral.

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The top photo is of an herb spiral in the Master Gardner’s test garden in Frederick Maryland.

Understanding the Herb Spiral Concept

Herb spirals are known for their space-efficient design, making them a perfect fit for both urban and suburban gardens. In the center the spiral is the tallest and as it expands around it gets shorter. The concept is very simple. But the result is magical! In 3 or 4 square feet of ground space, you can get as much as 12- to 15-square feet of gardening space.

They maximize the use of available space, making them ideal for smaller yards or even balconies. A significant attraction is the accessibility herb spirals offer. The design allows for easy reach and maintenance of herbs, reducing the strain on the gardener.

They are in essence, spiral shaped raised beds. One of the advantages they share is that you can build healthy soil on top of the ground. This is not only a no-dig gardening method, it also gives you maximum control of your soil.

Herb spirals provide a creative way to grow a wide variety of herbs in a relatively compact area. This diversity not only enhances culinary experiences but also supports garden biodiversity. The spiral’s structure also promotes water conservation, reducing the need for excessive irrigation. These are just a few ways that herb spirals align with sustainable and regenerative gardening practices.

Planning Your Herb Spiral

The importance of Planning

Before you dive into the construction of your herb spiral, it’s crucial plan carefully. Planning helps you make the most of your available resources, whether it’s space, materials, or time. Thoughtful preparation ensures that you won’t waste any of these valuable assets.

Careful planning helps you avoid common mistakes that could hinder the growth of your herbs or the functionality of the spiral. If you have miscalculated important aspects, like sunlight and available space, it’s difficult and, frankly, disheartening to have to tear it all apart. So, measure twice, cut once, as the carpenter says.

Optimal Location Considerations

• Sunlight Exposure: One of the most critical factors when planning the location for your herb spiral is sunlight. Herbs typically require a certain amount of sunlight to grow and thrive. You’ll need to select a location that receives adequate sunlight throughout the day. This ensures your herbs get the energy they need to flourish.
• Accessibility and Convenience: You also need to choose a location that is accessible and convenient for you, the gardener. It should be a place where you can easily reach the herbs for planting, maintenance, and harvesting. This accessibility reduces the effort required for tending to your garden.
• Microclimates: Microclimates are different areas of your yard that may have slightly different conditions. They can result from factors like sunlight, wind, shade, nearby structures, or low-lying areas. To evaluate these microclimates in your garden observation is the key. Notice how the sunlight moves during the day, and areas that are exposed to wind. Nearby structures can create shade or temperature differences.
• Adapting the Herb Spiral: The herb spiral’s design allows for flexibility. The spiral itself creates microclimates. It’s possible to incorporate them by adjusting the orientation and positioning of the herbs. This adaptability is one of the unique benefits of herb spirals.
• Proximity to the Kitchen: If it is important to you, a location close to the kitchen can be convenient for culinary herb gardening. When I’m cooking and I need fresh herbs, it is so convenient to step out to the herb spiral right outside the door.

The planning phase is probably the most important, and it is unique to every garden. There is no wrong or right way to plan the spiral, as it all depends on your particular location. This tailored approach ensures that your herbs will receive the optimal growing conditions for a successful garden.

Materials and Tools Needed for Your Herb Spiral

Herb spirals can be created out of several types of materials. Many people find landscaping bricks like the ones in the top picture convenient. They easily form a circular wall as you stack them. You can use bricks, cement blocks, or stones. Stones will take a little more trial and error getting them to fit together and be sturdy.

One of the eco-friendly benefits of herb spirals is the repurposing of things you might consider waste. Old bricks, blocks, wood, broken cement, and anything else you can reimagine. Look at this herb spiral made with stones and old wine bottles! That’s clever recycling. Image curtesy of Instructables.

I was “gifted” with several longs by a landscaper who dumped them (unwanted) along with the wood chips that I did request. I made an herb spiral out of the smaller logs. See the picture below. It works just fine. (Fortunately, the logs were birch, which are a hardwood, so we split the rest and now have firewood for winter.)

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how to make an herb spiral: Step-by-Step Guide

Here’s what you’ll need besides bricks or stones:

Essential Materials

• Soil: High-quality, nutrient-rich soil is essential for the health of your herbs. Consider a mix of garden soil and compost to create an ideal growing medium.
• Compost: Compost adds essential nutrients and improves soil structure. It’s a key component for creating fertile soil within the herb spiral.
• Gravel or Sand: A layer of gravel or sand at the base of the spiral aids in drainage, preventing waterlogging in the lower layers of the spiral.
• Landscape Fabric: Landscape fabric can be used to line the interior of the spiral structure, preventing soil from eroding through the cracks while still allowing for drainage.
• Mulch: Mulch helps to retain moisture and suppress weeds. It’s applied to the surface of the herb spiral after planting.

I wanted to mention here that the higher center of the herb spiral is also a good place to start with a layer of twigs and branches on the bottom. Hügelkultur is a method of layering a garden bed, starting with decaying wood on the bottom. It works well in raised beds and the deeper part of an herb spiral.

Essential Tools:

1. Shovel: A shovel is crucial for digging and moving soil. A sturdy spade or garden shovel will be helpful for this project.
2. Level: To ensure that your herb spiral is stable and even, a carpenter’s level is necessary to check the alignment of the bricks or stones.
3. Trowel: A garden trowel is useful for planting herbs and arranging the soil within the spiral.
4. Gloves: Gardening gloves protect your hands while handling soil, stones, and plants.
5. Wheelbarrow or Garden Cart: These tools make it easier to transport materials like soil, compost, and stones to the construction site.
6. Measuring Tape: To ensure accurate dimensions while building your herb spiral.
7. String or Rope: Useful for marking the spiral’s shape on the ground to guide the construction.
8. Watering Can or Hose: You’ll need a watering can or hose to moisten the soil and herbs during and after planting.
9. Scissors or Utility Knife: For cutting and shaping the landscape fabric as needed.
10. Safety Glasses: When working with bricks or stones, safety glasses can protect your eyes from flying debris.
11. Spirit Level: This tool is essential to ensure the spiral’s layers are level and stable.
12. Stakes and Twine: These can help in defining the spiral’s shape on the ground before construction begins.

By having these essential materials and tools on hand, you’ll be well-prepared to build a successful and thriving herb spiral in your garden.

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Step-by-Step Instructions for building an Herb Spiral

Creating the Base and Center

1. Mark the Center: Begin by marking the center point of your chosen location for the herb spiral. You can use stakes and twine to outline the spiral’s shape.
2. Excavate the Base: Using a shovel, dig a shallow, circular trench at the marked center. This trench will serve as the base of your herb spiral. Ensure it’s level and even.
3. Add Gravel or Sand: To improve drainage, add a layer of gravel or sand to the trench. This will prevent waterlogging and keep the lower layers of the spiral from becoming too wet.
4. Place a Central Object: In the center, place a larger stone, pot, or another suitable item. This central object will help create the spiral’s height and shape.

Laying the First Layer of Bricks or Stones

5. Select Your Building Material: Choose the bricks or stones you’ll use for the first layer. Ensure they are stable and level.
6. Start from the Center: Begin the first layer by placing bricks or stones in a circular pattern around the central object. These should form a stable foundation for the rest of the spiral.
7. Check for Level: Use a spirit level to make sure the first layer is even and stable. Adjust the bricks or stones as needed to achieve a level base.

Adding Soil and Compost

8. Layer of Landscape Fabric: Line the interior of the first layer with landscape fabric. This helps prevent soil erosion while allowing for drainage. (optional but a good idea)
9. Add Soil: Fill the interior with a mix of soil and compost. The depth of this layer depends on your design, but typically it’s about 6-8 inches deep.
10. Use Organic Matter: As stated above, if you are using the Hügelkultur method, place branches, twigs, wood chips, etc. in the center where the soil will be the deepest. Not only will you save on soil and compost, you will add organic material at the bottom. The organic material will break down over time and you’ll need to add more soil as it does.

Building Layers in a Spiral Pattern

11. Layer by Layer: Continue adding subsequent layers of bricks or stones in a spiral pattern, working your way up from the base. Gradually decrease the diameter as you go up, creating the spiral effect.

12. Stagger the Bricks or Stones: To create stability and strength, stagger the placement of bricks or stones in each layer. This will help maintain the integrity of the structure.

Planting Herbs as You Go

13. Select Herbs: Choose the herbs you want to plant in the herb spiral. Keep in mind the sunlight and moisture requirements of each herb. Select herb varieties that align with the microclimates in your garden. For example, Mediterranean herbs like rosemary and thyme thrive in sunny, well-drained areas, while mint and chervil may prefer shadier, moister locations.

14. Plant Strategically: As you build each layer, dig holes for your selected herbs and place them in the appropriate locations. Place taller herbs toward the center and shorter ones near the edges to optimize sunlight exposure.

Watering and Mulching

15. Water Carefully: After planting, thoroughly water the herbs to help them settle and establish roots. Ensure the soil is evenly moist but not waterlogged.

16. Apply Mulch: Spread a layer of mulch on the surface of the soil to retain moisture, suppress weeds, and maintain even soil temperatures. This also gives the herb spiral a neat appearance.

By following these step-by-step instructions, you’ll successfully create an herb spiral in your garden. The spiral not only provides a functional and space-efficient herb garden but also enhances the aesthetics of your outdoor space.

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Caring for Your Herb Spiral

Like any newly installed garden bed, you will want to water regularly while the plants are getting established. Check the moisture levels all around the spiral by inserting your finger up to two inches. If it feels dry, it’s time to water. Most of the spiral should have good drainage due to it’s design. But still avoid overwatering to prevent waterlogged soil.

Also like the rest of your garden, you’ll want to keep an eye out for weeds and pull them before they take root. I have found that the weeds are fewer and easier to manage because they aren’t coming up from the ground in most of the herb spiral. I only have to pluck out errant weeds that come from seeds falling into the soil.

Trim and prune your herbs as needed to encourage healthy growth and maintain the desired shape of the spiral. Frequent harvesting also keeps herbs productive and prevents them from becoming too woody.

Periodically add compost or organic fertilizers to replenish nutrients in the soil. This helps sustain herb growth and prevents nutrient depletion.

Benefits of the Herb Spiral’s Design in Reducing Maintenance

• Efficient Space Utilization: The vertical design of the herb spiral condenses a variety of herbs into a small space. This design minimizes the overall garden area, reducing the time and effort required for maintenance. It’s an efficient use of space, particularly in smaller yards.
• Reduced Bending and Stretching: The spiral shape allows for herbs to be easily reachable from the sides of the structure. This minimizes the need for bending or stretching, making it a more ergonomic and accessible gardening option. Gardeners, especially those with physical limitations, appreciate this advantage.
• Self-Watering System: The higher layers of the spiral tend to shed excess water to the lower layers, creating a self-watering effect. This design helps maintain consistent moisture levels in the soil, reducing the frequency of manual watering.
• Natural Mulching: The upward spiral shape creates a natural gradient for mulch to remain in place. Mulch helps retain moisture, regulate soil temperature, and suppress weeds. Its effective use reduces the need for frequent mulch replacement.
• Companion Planting: Many herbs have natural pest-repelling qualities, and by planting them in close proximity, the herb spiral can benefit from natural pest control. This design strategy reduces the reliance on chemical pesticides.

Criticisms of Herb Spirals and My Response

Most often when you see an article about herb spirals they are linked with the practice of permaculture gardening. As a fair-weather student of permaculture, I’m not sure why. Is an herb spiral absolutely necessary for a permaculture garden? No. Are they fun to look at and work with? Sure. But they are not a “must-have” in Permaculture.

Do you need to learn how to make an herb spiral to make your garden complete? Of course not. The main advantage of herb spirals is their ergonomic, space saving design. Just like you don’t need to have raised beds to garden successfully, they sure are nice to have. It comes down to preference.

I will opine, if you don’t mind. One of the values that I see in herb spirals is that they serve as great teaching models. Through my own experience with my herb spiral I have learned about microclimates, about shade tolerances of my herbs, and about ergonomics. As I look ahead, my retirement years are not far away and I really like the ability to run right outside my back door and snip some basil and oregano without bending and stooping!

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FAQ’s About Herb Spirals

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