Curl Up in the Garden
by Michael Lockman (michael(at)we-design.net)
Copyright Michael Lockman. All Rights Reserved.
Herb spirals accommodate plants of every nature in compact, colorful form.
Suggesting both the ordered form of a conch shell and the disarray of an English garden, an herb spiral is ideal for growing herbs in small spaces. Compact and colorful, and busy with honeybees and other insects, the raised, spiraled garden bed built up with rocks and soil is a unique collection of culinary, medicinal, and fragrant plants that provides food for the mind, body, and soul. The herb spiral is truly an ecosystem unto itself, filled with beautiful and useful plants.
Spirals range in size from 4 to 5 feet across and 2 feet high to 10 to 15 feet across and 3 feet high. One benefit of the raised, spiraled shape is that you can grow in one small space plants requiring a variety of growing conditions. The herb spiral has two diverse microclimates, ranging from a sunny, dry area on the upper southern half to a shaded, moist area on the north and around the base. The raised top drains quickly, and the base gets all the water run-off. As a result, you can grow herbs, greens, medicinals, bulbs, and flowers on one spiral. And the spiraled bed provides more growing area than garden rows.
Siting the Spiral
Because most herb spirals serve culinary purposes, they should be placed close to the kitchen. When deciding where to place your spiral, notice where you walk every day: from the car to the house, to the mailbox, to the bus stop with the kids. By integrating the herb spiral into your daily traffic patterns, you are more likely to enjoy and maintain your garden regularly, harvesting and using what you grow.
Integrating a path across larger spirals (6 feet or more across) allows access to the center from various directions and makes maintenance and harvesting much easier. Use small stones, bricks, or rocks to create places to step into the herb spiral. The path may be nothing more than two or three steps, one on each level of the spiral, that allow you to harvest from the center.
An herb spiral offers at least two microclimates for herbs. Mediterranean herbs, which require well-drained soil, are ideally suited for the upper half. They benefit from the rocks, which capture heat during the day and release it into the soil at night. Herbs that do well in these conditions include rosemary, thyme, lemon thyme, marjoram, oregano, artemesia, and sage. The base and lower areas of the spiral are perfect for growing herbs that can tolerate shade and water runoff. Mint, lemon balm, pennyroyal, chives, chamomile, mayflower, and summer savory are a few herbs perfectly suited to this microclimate.
There is always room to include Italian and curly parsley, sorrel, salad burnet, mustard, chard, and kale greens. These self-seeding annuals will provide a constant supply of salad greens until the herbs fill out the spiral and shade them out. Edible flowers such as nasturtium, calendula, and borage do well at the base. They will eventually roam all over the spiral, providing beauty, increased opportunities for pollination, and edible garnishes. Egyptian or "walking" onions are also a great bulb addition. As the name suggests, the 18-inch tall seed stalks bend to the ground as they wither in the fall, depositing 'sets' that form atop the stalk to grow next year's onions. Each year they spread a bit further, providing fresh onion greens and the occasional shallot-like bulb.
Soil: a fertile mix of , topsoil, and sand recommended for fill or mounding applications, approximately ½ a yard for a small (4'x4'x2') spiral; and a full yard of soil for a larger (10'x10'x3') spiral.
Rocks: approximately 20 rocks, ranging from football to softball size.
Plants: 15 and 20 plants for a small spiral: one each of oregano, thyme, lemon thyme, rosemary, sage, chives, summer savory, chamomile, lemon balm and mint; two to four starts of parsley, kale, sorrel; seeds of calendula, nasturtium, and borage to be planted throughout the spiral, particularly around the base and in any open spots.
Making the spiral
- Place a garden hose on the ground in the shape of a circle. Mark this outside circular edge by digging a shallow trench as wide as the rocks you are using, and about 3 inches deep. Remove the hose.
- The key to a stable herb spiral is making sure the rocks are set; if they are not set the spiral may settle or even fall apart. Create the first layer of rocks for the base by stacking them 2 to 4 inches deep, as close together as possible, and pack dirt around the rocks so that 1/3 to ½ of each rock is buried and remains firm when you try to move it. Once you have the first course of rocks set, pack dirt inside the circle to form a level bed up to the height of the rocks. Your goal is to create a round bed that is level with the rock border. Use the end of a hand tool or a stick to tamp the soil until firm.
- Begin the second layer of rocks, spiraling as you go and again filling in with dirt to create a level surface. Continue this as you wind upwards, using smaller rocks as you approach the top and making sure to tamp the soil until firm.
- Lay out the plants (still in their pots) on the spiral to determine spacing, giving careful thought to their growing habits. Rosemary, for instance, can get quite large and should be placed at the top or on the upper backside. In contrast, creepers like thyme and marjoram should be planted so that they can cascade down the front. Mint, lemon balm, and pennyroyal need lots of running room to spread, so plant them around the base. In general, herbs in rows should be planted 12-24" apart. On an herb spiral the plants can be closer because there are different levels on which to grow. Plant herbs that will grow on the same level at least 18" apart and stagger placement so that herbs on one level are not growing directly above or below herbs on another. Intersperse with kale, parsley, broccoli and other annuals to provide cutting greens and vegetables until the herbs fill out.
- Begin planting at the top of the spiral. Use a small trowel or soil knife to dig a hole slightly larger than the herb's pot and collect the soil in a bucket. Pop the herb out of its pot and place in the hole. Use soil from the bucket as needed to fill spaces around the plant. Press the dirt firmly with your hands and move down the spiral.
- Thoroughly water the spiral. Water the spiral once a week during the first summer to help the herbs get established. Once the herbs are established you should only have to water in drought-like conditions.
The herb spiral is the perfect design to grow all your culinary and medicinal herbs. You may wish to customize your spiral depending on your herbal preferences. Some possible themes include:
Aromatic Herbs: Lavender, sage, rosemary, and fennel
Tea Herbs: spearmint, peppermint, lemon balm, and chamomile
Full-moon Herbs: Artemesia, evening primrose, lamb's ear, and Chinese lantern.
Herbs for Relaxation: chamomile, valerian, skullcap, and hops (grow these up a trellis on the backside of the spiral).
Herbs for the Immune System: Echinacea, garlic, yarrow, and coltsfoot
Watering is essential for full production; water weekly or more depending on your location during the spiral's first year. (Once the herbs are established, you should only need to water in drought-like conditions.) The shape allows for easy watering, as one sprinkler placed at the top will water the entire spiral. Or you can hand-water the top of the spiral, and gravity will do the rest.
A number of edible '`weeds'' may find their way into your spiral. Fennel, dandelions, and chicory are three with beautiful flowers that attract bees and beneficial insects. Identify the weeds to find out if they are edible or otherwise useful before you banish them.
A handful of plants need extra care. Mint and lemon balm, for example, are herbaceous perennials that die back every winter and expand their growth footprint every warm season. Diligently remove new runners before they take over the spiral.
To give your herb spiral eye catching dimension, dig a small pond and use the unearthed soil to build the spiral. For easy construction and maintenance, place the pond at the base of the spiral. Line the pond with a rubber liner or dig a hole and bury a 20- to 33-gallon trashcan with rocks placed along the rim to maintain consistency with the spiral.
While 32-gallon trashcans are a viable pond option, the steep sides make the pond difficult, if not impossible, for birds and other wildlife to access. If raccoons or dogs are a problem, this can be used to your advantage. Use a small satellite dish or a large (10-20 gallon) plastic plant container to extend the lip of a 32-gallon trashcan. By cutting a hole in the wider edge and gluing it to the trashcan, you not only deter predators by creating a 'deep-end' safety zone for your fish, but you also allow birds to drink and bathe on the shallow sides. Appropriate fish species include goldfish and minnows.
Edible plants for your pond include watercress, water chestnuts, and arrowhead or Wapato. If your pond is at least three feet deep, you can experiment with wild rice, water lotus, and water lily. Edible reeds, rushes and grasses can be incorporated into both shallow and deep ponds, providing additional food for humans and wildlife.
Pond liner: The size of the liner will depend on the size of the pond you want to create. To calculate the amount of pond liner you need, take the depth of the pond times 2 plus the diameter of the pond plus 2 feet for Overhang. The idea is to come up with a square footage measurement. For example, if the pond is 2 feet deep and has a diameter of 3 feet then you want a square liner that is 9 feet by 9 feet. [(2 X 2) + 3 +2 = 9] Pond liner is usually available at your local hardware store or from a pond supply company.
Abotu the Author
Michael Lockman, author of Curl Up in the Garden, founded WE-Design in Seattle, WA, a landscape design business specializing in edible landscaping, backyard wildlife habitat, and water catchment. A contributing writer for magazines such as Communities, Simple Living Journal, Pacific Northwest Gardener, and mybackyard.com, he also co-teaches a month-long Sustainable Skills study course on Orcas Island, Washington. Michael is an adjunct faculty member at Antioch University Seattle's Environment and Community Master's Program, and an avid gardener and backpacker in his spare time. For a personalized herb spiral design for your garden, contact Michael at michael(at)we-design.net or visit www.we-design.net to view a portfolio of his designs.