The dizzying beauty of a herb spiral right in your own garden

Herbs, today, are definitely among favored options when planting an ornamental garden. Purple basil, the many varieties of oregano and thyme, graphic-leaved fennel… All these fragrant wonders turn flower beds into olfactory landscapes, too! Most even have no fear of drought or excess sun: they’ll just keep growing even in rocky soil, flower beds, sneak along between tiles on a terrace or plump out a windowsill garden box!

1- What makes an herb an herb?

“Herb” is a term that brings together a great diversity of plants that all share a common trait: some part of them has a high concentration of essential oils, be it the root, leaf, flower or seed. In cooking, they complement and modify the taste of other ingredients. In alternative medicine, their therapeutic properties help alleviate ailments and more. The list of herbs is very long, and each country has its own traditions and customs.

Generally, it’s recommended never to over-use an herb. Even if the plant itself isn’t toxic, if eaten in large amounts and high doses it might still lead to trouble.

Shrubs, perennials and annuals, a compendium of all herbs

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  Shrubby herbs such as thyme and rosemary are generally considered native to the Mediterranean basin. As a result,they’re ideal to form low edges or to fill in patches of color in a checkered tile garden. Creeping rosemary varieties (Rosmarinus officinalis ‘Pointe du Raz’) will gracefully flow and cover a mound or low wall.

These shrubs need pruning in February, or just after the blooming. Of course, you can always snip a twig off now and then for your cooking. They demand full sun and don’t need any help overcoming drought.

• Perennial herbs more or less all wilt away during the wintertime. They call for a back-to-the-ground pruning every month in spring and summer. Usually, a lot of water is needed to keep them lush, and they grow best in part shade, except for fennel.

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  Annual herbs require sowing every year, much of which occurs naturally as they go to seed and die away. Trim them often and water them abundantly after planting. The longer you water, the later they will flower and bear seed. They all love full sun, except for chervil which prefers shade.

• Biennials such as parsley typically need 2 years to develop. Over the first year, they just produce leaves, but then flower and bloom the second year. It doesn’t matter to them whether they’re in full sun or in the shade.

2- Main herbs and spices

There are exceptions, but generally speaking herbs can be classified as follows:

Shrubby (sun, dry soil)

• hyssop (Hyssopus officinalis)
• bay (Laurus nobilis)
• lavender (Lavandula angustifolia)
• english lavender
• marjoram (Origanum vulgare)
• rosemary (Rosmarinus officinalis)
• savory (Satureja montana)
• sage (Salvia officinalis)
• wild thyme (Thymus serpyllum)
• thyme (Thymus)

Perennials (part sun, cool soil)

• lovage (Levisticum officinale)
• agastache (Agastache)
• chives (Allium schoenoprasum)
• tarragon (Artemisia dracunculus)
• fennel (Foeniculum vulgare): dry soil
• mint (Mentha)
• lemon balm (Melissa officinalis)
• sorrel (Rumex arifolius)
• rhubarb (Rheum x hybridum)

Annuals (full sun)

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  dill (Anethum graveolens)

• basil (Ocimum basilicum)
• borage (Borago officinalis)
• chervil (Anthriscus cerefolium): shade
• coriander (Coriandrum sativum)
• cumin (Cuminum cyminum)
• annual savory (Satureja hortensis)

Biennials (part sun, sun)

• garden angelica (Angelica archangelica)
• caraway (Carum carvi)
• parsley (Petroselinum sativum)

3- Making a herb spiral

Here is a landscaping arrangement designed to give each herb exactly the soil and exposure it needs. The trick is to build up a mound with a spiral and a rock wall. Then, settle the plants in the spot that suits them best.

How to build it

• Stack up soil into a cone about 5 feet tall (160cm) and 3 feet wide (1m). This size is perfect to harvest the herbs without needing to actually climb into the herb spiral. For the base and the center of the spiral, use poor soil, and what’s most important is that it drains very well (mix in gravel, rocks, sticks…).
• Mark due North, and then from the tip of the cone start tracing a spiral with a rock ledge, as shown in the picture. Make sure the stones are sunk at least ¼th into the soil for stability. The rocks, preferably chalk or limestone, help absorb heat and reduce temperature swings.

The planting

• Climbing up the spiral, with particular consideration to the exposure of each spot, plant the following species:

1- watercress 2- parsley 3- mint 4- pennyroyal 5- sorrel 6- celery 7- dill 8- savory 9- chives 10- basil 11- lemon balm 12- tarragon 13- sage 14- hyssop 15- rosemary 16- oregano 17- thyme

The spiral itself provides cooler, shaded spots on one side, and warmer, sunnier spots on the other. Remember to add a mini-pond at the bottom of the spiral to catch runoff: you can plant watercress or water mint.

• The tip of the spiral is where dry-soil plants should go, like thyme, rosemary, lavender, hyssop and sage.
• The middle section is reserved for basil, chives, burnet, oregano and tarragon.
• The lower base is where plants that need the most water live: chervil, cumin, dill, parsley, lemon balm and mint.

Go ahead and cut back clumps that grow too large in order to give every plant the same growing space.