Planting in a plastic liner that fits a wood, metal, or other box makes changing the plantings easy. Toward the end of the gardening season, remove annuals from the window box and compost them; transplant perennials to the garden, doing so early enough to give them time to establish themselves before winter.
- 6 to 10 herb plants in 3-inch pots (rosemary, parsley, oregano, lavendar, mint, etc.)
- Lightweight potting mix
- Compost or composted manure
- Water-retentive polymer crystals
- Window box and plastic liner sized to match your windowsill
- Watering can
1. Plan. Before planting, set the potted herbs in the window box. Arrange them as you please. Consider plant heights, as well as growth habits, such as spreading, upright, and trailing. Punch drainage holes in the bottom of the liner if there are none.
2. Fill the box halfway. Use lightweight potting mix enriched with compost or composted manure. Mix in water-retentive crystals, following directions on the package label.
3. Unpot. Unpot the plants. Gently loosen the root balls; in particular, loosen roots at the bottom of the root ball. As you set the plants in the window box, spread the roots over the soil to ensure that the roots will spread into the new soil after planting instead of continuing to encircle the root ball.
4. Plant. Set plants at the same depth they were growing in their nursery pots, spacing them about 2 inches apart. Add potting mix, filling the box and gently tamping it to settle the soil. Leave about 1 inch of space between the soil surface and the rim of the box.
5. Water the soil thoroughly. For best growth, set the box in an east or west window outdoors or a south window indoors.