Wednesday, June 18, 2014

How to Build an Herb Spiral

After Bea decided to turn the ugly dead-tree laundry pole into a focal point (a bottle tree!) for our new garden, she also wanted to put in an herb spiral at its base.  Neither of us had built one of these before, so after a lot of googling, we settled on the following procedure.  All told, it took about 8 hours to build, albeit that was with only one person working, and with some breaks factored in as part of that time estimate.  It's probably a half-day project with a couple of people just gettin'-it-done.

Step 1: Find some old bricks or stones (or new ones if you prefer)

Bea found a huge pile of weathered old bricks under the overhang on the back of the outbuilding we call the chicken coop (no, we don't have chickens...yet).  She had been trying to come up with a project to use them up so we could walk through without clambering over the brick pile; this find helped inspire the herb spiral idea in the first place.

Step 2: Set up your circle

Once you have a good supply of bricks, install a stake temporarily into the spot you want to be the center of your herb spiral.  In our case, we didn't need a stake, we just worked from the dead tree/bottle tree.  Get a string or tape measure and use it to mark out a perfect circle.  Remove any weeds/vegetation growing in this area (Bea dug it up lightly to loosen the soil).  If you were doing this in the fall, you could put down cardboard or layers of wet newspaper to avoid the weed removal, but in spring when they're growing rapidly, it's best to just put in the effort to remove them.  Our circle has a 3' radius.

Step 3: Lay out your spiral

Use your bricks/stones to mark out a spiral.  Keep in mind that depending on what you plan to plant, a lot of herbs like to spread out so they'll need plenty of space.  We only built a two-layer spiral with each layer being 18" wide.

Step 4: 

Fill in your spiral with a layer of compost.  You can put compost in between the bricks too to help hold everything together.









Step 5: Cover with straw

Make sure you get straw, not hay -- hay is for animals to eat and thus contains nutritious seed-heads (which will sprout in your garden).  Straw is just dry stalks without seeds, and much more suitable for use in mulching a garden!

The straw will break down slowly and continue providing nutrients to your growing plants over time.


Step 6: Build up a second layer of bricks

Place a second layer of bricks over top of the first around the spiral.  You'll want your spiral to end up sort of like a pyramid/cone, with the center being tallest -- so taper off on stacking the bricks as you get towards the bottom.  Don't forget to stagger your bricks as you stack them, like in a brick wall!  So each brick you place on the spiral should overlap two bricks below.  If you're working with brick pieces instead of whole bricks, just do your best to overlap joints so they don't fall over and collapse.

Step 7: Fill in with compost, repeat as many times as needed

You'll repeat the brick/compost/straw layers until you either run out of materials or until your spiral reaches its desired height.  Ours is 4 layers of bricks at the top and 1 at the bottom, or about a foot and a half tall in the center.

Step 8: Get ready to plant!

Part of the beauty of an herb spiral is that it gives you multiple “planting zones" suitable to growing a variety of herb plants.  The soil at the top of the spiral will dry out quickest, while the bottom of the spiral will remain moister.  In the northern hemisphere, your southern part of the spiral will get direct sun most of the day while the raised nature of the spiral will provide some shade for the northern side.  The taller and larger your spiral is, the more customized you can make each position for your plants (just don't forget you'll need to be able to reach into the middle to harvest!).

So now you've got some choices to make -- note that some herbs do well in multiple positions:

Sunny Dry Positions (at/near the top of your herb spiral) – aloe vera; bay tree; garlic chives; lavender; marjoram; oregano; rosemary; sage; tarragon; thyme

Shady Dry Positions (on the northern side, in the shadow of your spiral and/or taller plants) – basil; nasturtium; oregano; parsley; sage; tarragon; thyme; yarrow

Sunny Moist Positions (middle/southern side of herb spiral) – arugula; bergamot; chives; cilantro/coriander; nasturtium; parsley; sorrel; spring onions; strawberries

Shady Moist Positions (middle/northern side of herb spiral) – arugula; borage; chamomile; chives; parsley; sorrel; strawberries; violets

Sunny Wet Positions (bottom of herb spiral on the southern side) – chamomile; mints

Shady Wet Positions (bottom of herb spiral on the northern side) – ginger (harvest before frost); lemon balm; mints; watercress (often installed in a shallow pool at the very bottom of herb spirals)

Chris came out to help right in time for the fun part!

You'll have best success if you plant transplants (as opposed to direct seeding) in your herb spiral, so start by placing all your plants in pots around the spiral.  This way you can move them around to space them evenly and move as many times as you need until they're exactly where you want them.  Once you're ready, just go ahead and pop them into the ground.

Since the spiral is constructed of straw and compost (both of which drain very easily), you'll need to water deeply and daily until your new plants are well-established!

East side
South side

West side
North side
Our completed bottle tree/herb spiral garden centerpiece!





No comments:

Post a Comment