Although any pallet will serve as the backbone of your garden, it’s important to pay attention to wood quality—particularly if you plan to grow edibles. Chemically treated wood pallets have a slight green hue, especially when newly treated. Look for ‘HT’ stamped somewhere on the pallet to ensure it’s been heat-treated and is safe for vegetable production. A pallet stamped ‘MB’ means it has been exposed to Methyl Bromide— a toxin you definitely don’t want leaching into your garden soil.
Once you’ve carted off a couple of those pallets piling up behind your local grocery store (ask first!), clean them up a bit. Sand rough edges, removing any snags or hanging staples, and secure loose planks.
In addition to your pallet, here’s what you’ll need:
+ A couple bags of potting soil like Espoma Organic Potting Mix ($38 on Amazon), or a rich compost blend for growing vegetables.
+ A roll of landscape fabric ($15 on Amazon).
+ A staple gun ($14.50 on Amazon).
The landscape fabric will form the bedrock of your garden and ensure that all of your soil doesn’t spill out. First, lay your pallet down with the slats against the ground and staple the fabric securely around the pallet’s sides, back, and bottom (don’t seal up the top if you plan on propping it vertically or hanging it— this is how you’ll water your garden). Make sure the fabric is taut and not sagging. Next, flip your pallet over and fill it with soil, packing it down firmly as you go. It’s easiest to fill up your pallet while it’s lying down, slats up.
Virtually any herbs, veggies, or small perennials and annuals will grow in a pallet garden. Bear in mind that if you plant perennials, these long-lasting plants may eventually demolish the pallet’s wood and require a new fabric backing.
If you plan on propping the pallet up or hanging it from a wall, select a plant that dangles or climbs like trailing nasturtiums or morning glories (and use large caliber masonry screws to attach the pallet to the wall). Tomatoes are natural climbers too, as are cucumbers and gourds.
Consider choosing groups of plants that have similar light and moisture requirements. A hummingbird pallet garden with a slightly shady aspect might have orange nasturtiums, a few bright impatiens, and some aromatic scarlet petunias cascading down the side. A bee-magnet pallet garden could double as a hot, sunny herb garden with lemon basil, hyssop, lavender, and trailing thyme. Even cooler, how about a moth pallet garden replete with night blooming flowers like the native evening primrose, some pale four o’clocks, and a moonflower vine cascading down the side?
You can even create a succulent pallet garden, but make sure these slower growing plants have time to develop roots before setting your garden upright—3 weeks should do it.
Finally, after you plant your fruits, veggies, or flowers between the slats, remember the golden rule of these freely draining upright gardens: water, water, water!