Weigela (Weigela florida) is a deciduous shrub desirable for its profusion of flowers, which are pink, white or red, according to the University of Connecticut. Often called "Old-fashioned Weigela," this plant is native to Japan and thrives in U.S. Department of Agriculture (USDA) zones 5 through 8. Good companion plants for weigela are those that grow in the same USDA plant hardiness zones, have the same care needs, and compliment the appearance of the weigela rather than compete or blend in with it.
Peonies (Paeonia sp.)
Peonies make excellent companion plants to dwarf varieties of weigelas, according to Monrovia. They are perennial plants and will return to bloom year after year along with the weigelas. The elegant form and tall, large blooms of peony plants are beautiful when placed behind a row of short, 3-foot weigelas, especially if the shrubs are used to line a walkway or border. Use peonies in a contrasting color for maximum visual impact, or use the a similar-hued variety in a color-themed planting bed.
Hydrangea (Hydrangea sp.)
Hydrangeas are very similar to weigelas. Like weigelas, they prefer cool, moist climates, have large, interesting leaves and bloom with showy clusters of flowers. These shrubs have flowers that are white, pink or blue, depending on the acidity of the soil. Hydranges are usually larger than most weigelas, so tuck your weigelas around and under your hydrangeas. This pairing makes an excellent specimen group in any home garden.
Barberry (Berberis sp.)
Use barberry as a companion plant to large varieties of weigelas (those that get up to 6 feet tall). "French Lace," for example, is a weigela cultivar that reaches heights of over 6 feet. This variety has bright-green, variegated leaves, which contrast nicely with any plant that has burgundy foliage, according to Monrovia. Japanese barberry (Berberis thunbergii) is a small shrub with foliage that remains a bright burgundy color throughout the growing season. In addition, it has the same temperate-climate culture needs. Alternate barberry bushes with weigela shrubs for a colorful hedge that will remain beautiful from spring to fall.
Delphinium (Delphinium sp.)
Delphinium flowers tower majestically above most varieties of weigela. The beauty of these perennials is that many varieties of delphinium come in shades of blue, which contrast stunningly with the white, pink or red flowers of weigela shrubs. Go patriotic in your garden this summer. Create a red, white and blue theme by planting blue delphiniums behind red and white flowering weigela varieties.