Whiskey barrel gardens charm with their rustic beauty and the fact that once established, they require little investment of time and energy. If your whiskey barrel doesn't have drainage hole in the bottom, use a drill to make at least two or three 1-inch holes. Cover the holes with a piece of screen to prevent potting mix from washing through. Fill the barrel to within 2 to 3 inches of the rim with a good quality peat-based potting mix.
Hosta (Hosta spp.), suitable for growing in U.S. Department of Agriculture plant hardiness zones 3 through 8, provides an ideal focal point for a barrel in semi-shade or filtered light. These versatile plants come in various shades of deep green, blue-green or gold that are often edged or splotched with creamy white or greenish-yellow. The shape, size and texture of the leaves is just as varied, with heart-shaped or sword-like foliage and smooth or crinkled leaves ranging in size from petite 6-inch plants to giants at heights of 3 to 4 feet. Let hosta shine on its own or surround it with shade-tolerant, woodland perennials such as Johnny jump-ups (Viola tri-color), perennial in USDA zones 8 through 11, or coral bells (Heuchera spp.), suitable for growing in USDA zones 4 through 9.
Kale for Winter Color
Ornamental cabbage or flowering kale (Brassica oleracea), suitable for growing in USDA zones 1 through 11, awakens a winter landscape. Colors range from creamy white to pink or intense purple, with the color intensifying as the weather turns colder. Depending on the variety, ornamental cabbage displays feathery foliage, crinkled edges or rounded leaves. Plant the barrel in autumn to allow time for the heads to develop fully before winter. Allow 10 to 15 inches of growing room per plant.
Evergreen Focal Point
Bright annual flowers provide a stunning contrast to slow-growing evergreen such as dwarf Alberta spruce (Picea glauca albertiana), hardy to U.S. Department of Agriculture plant hardiness zones 2 through 6, or Standish yew (Taxus baccata "Standishii"), suitable for growing in USDA zones 7 through 8. Plant the tree in the center of the barrel, then fill the space around the tree with 14 or 15 plants of a single type in two contrasting colors. For example, plant pansies (Viola x wittrockiana) in shades of bright purple and yellow or petunias (Petunia spp.) in lavender and red. Although pansies are often planted as annuals, they are perennial in USDA zones 8 through 11. Petunias are tender but may overwinter in USDA zones 9 and 10.
A whiskey barrel has plenty of space to supply vegetables for fresh salads all summer. You can plant most seeds for salad vegetables directly in the barrel, but if you want to get a head start, start seeds indoors and move them to the barrel after all danger of frost has passed. You can also purchase young plants at a garden center or nursery for an instant salad garden. Plant a cherry tomato plant in the center of the garden, then surround the plant with your choice of salad vegetables. A whiskey barrel holds approximately four lettuce or spinach plants, 10 to 12 green onions and radishes and six to eight beets, turnips or carrots, along with one or two herbs such as chives or parsley.