Spirea are a group of spring to summer blooming, deciduous shrubs. According to Sunset Plant Finder, spirea comes in two unique types: bridal wreath spirea and shrub-type spirea. Bridal wreath spirea produces an abundance of white to cream colored, 1/2-inch wide flowers. Shrub type spirea produces sweetly scented flowers that come in red, pink, white and yellow. Spirea is fast growing and once established is fairly drought tolerant.
Choose a planting area for the spirea that will provide it with full sun. Spirea can tolerate some light shade but prefers being planted in full sun.
Turn over the soil using a spade down to a depth of between 12 and 16 inches to mix in organic matter. Lay out over the planting area a 2- to 3-inch layer of sphagnum peat moss to help acidify the soil (spirea likes slightly acidic soil). Work the moss into the soil thoroughly. If the soil drains poorly or is less than ideal, spread out a 2-inch layer of aged manure or dehydrated plant-based compost over the planting area. Mix it into the soil using a spade or a garden fork.
Dig a planting hole for the spirea that is three times the width of the planting container and 1 1/2 times its depth.
Scoop a few shovelfuls of soil back into the planting hole.
Lay the container horizontally on the ground or potting bench if you have one. If you are planting spirea from a 1-gallon pot, use a hammer or a small piece of wood and give the rim of the container a few hard taps to loosen then remove the pot from the root system. If you are planting from a 5-gallon pot, use a pair of all-purpose snips to cut along the sides of the pot, starting at the drain holes.
Remove the spirea from its planting container gently. Inspect the root system of the spirea. Loosen any encircled, matted, or knotted roots using your fingers.
Plant the spirea into its planting hole. Make sure the spirea is not sitting too deep in its planting hole. The top of its root system should be sitting at the same height, or just slightly above (about 1 inch) the level it is currently growing at. Remove the spirea from its planting hole and scoop in more soil, if necessary, until you are sure it is sitting at the correct height in the hole.
Scoop in soil to set the spirea in its planting hole. Use your foot to pack the soil down around the root system. Fill the planting hole 1/2 full of soil. Pour in 2 to 3 gallons of water and fill the remainder of the planting hole full of soil as soon as the water has fully dissipated.