Foolproof plant combos
The fancier your window box, the simpler the planting should be. For example, an ornate, embossed metal or terra-cotta box filled with clipped boxwood spheres or spiky blue fescue grass looks understated and elegant.
However, most window boxes call for a collection of trailing and upright plants. Depending on the size of the container and restraint of the gardener, usually four or five types of plants offer enough variety (more and the collection loses its focus). Don't rely just on flowers for interest; foliage plants offer an array of textures and leaf shapes, which prevents a mix of plants from looking too busy.
Aim for a balanced—not necessarily symmetrical—look. There is no rule that says plants in window boxes need to look like soldiers standing at attention: a long row of red geraniums faced with a long row of trailing lobelia can be boring. If you're using one tall specimen as a focal point, try positioning it one-third in from either end and let shorter ones slope down on either side. Group similar plants together instead of scattering them throughout the box to create a more graphic, dramatic look. Trailing types don't need to be evenly spaced across the front: let random areas of the front of the box peek through.
Some combinations to try:
- For shade: Japanese painted fern, miniature blue-leafed hosta, asparagus fern and one dramatic caladium
- For part-shade: Pink verbena, white and pink impatiens, tri-coloured sweet potato vine, white bacopa
- For part-shade: Purple-leafed coral bells, purple trailing sedum, parrot's beak (Lotus berthelotii)
- For part sun: Purple heliotrope, yellow trailing snapdragon, white lantana, English ivy, Australian fanflower, pale yellow petunia, blue Nierembergia
- For part to full sun: Trailing rosemary, culinary sage, chives, flat-leafed parsley, small ornamental kale
- For sun: Golden creeping Jenny, yellow French marigolds, yellow-and-white variegated coleus, bidens
- For sun: Leatherleaf sedge, gold lantana, creeping zinnia, orange dahlia, red nasturtium