Though there are a number of plants referred to as buttonbush, this guide will focus on the common buttonbush, or Cephalanthus occidentalis. These shrubs contain cephalathin, which is toxic when ingested.
Light
Buttonbush prefers partial to full sunshine. It often grows better in full sun exposure but it can be a delicate balance. Shrubs planted where the sun readily dries out the soil will struggle to thrive.
Soil
Buttonbush is perfect for low-lying, wet areas where other plants may not grow well. It adapts to various soil conditions even though it is most often found in alluvial areas with sand and silt. Buttonbush prefers a neutral to slightly acidic soil with a soil pH level of 6.8 to 7.2 and does not perform as well in alkaline soil.
Water
These plants prefer wet conditions and do not tolerate drought. They can even grow in flooded areas. When located in an ideal spot, watering may not be required. However, if they are placed in an area where conditions may dry up, they will need regular watering. Aim to keep the soil moist at all times.
Temperature and Humidity
The hardy nature of buttonbush shrubs contributes to their success in USDA hardiness zones 5 to 11. They are heat-resistant, cold-resistant, and extremely resilient when faced with overly wet conditions. This makes them great for a wide range of climate. They look their best in temperatures ranging from 61 to 75 degrees F. and are tolerant of high levels of humidity as long as there is plenty of water available. Dry, arid conditions are not suitable for growing buttonbush.
Fertilizer
Buttonbush does best in nutrient rich soil and will benefit from yearly fertilizing. Add a slow-release fertilizer in the spring to encourage new growth and summer flowering. For new shrubs, it is best to wait until the following year to fertilize, as this gives them enough time to properly establish.
Types of Buttonbush
‘Bailoptics’: This cultivator is a small variety, only reaching about 6 feet high and 6 feet wide, making it great for smaller spaces. ‘Bieberich’: This variety reaches up to 12 feet high with a similar spread. It displays unique pale pink or pinkish-white blooms rather thanthe usual white flowers. Its leaves also turn a bronze color in the fall. ‘Sugar Shack’: This densely foliaged dwarf variety only reaches up to 4 feet high and 4 feet wide. Each spring and fall, its leaves take on a reddish tone..
Pruning
Because of its size, many people prefer to keep buttonbush pruned. When left to grow untrimmed, the shrub takes on an irregular shape. Wayward or scraggly branches can be trimmed away for a more manicured look. Alternatively, these shrubs can be limbed-up, which refers to removing lower branches to establish a more tree-like shape. If it becomes unmanageable, simply cut the shrub down to the ground in early spring. Because it is such a fast grower, it will produce new growth very quickly.
Propagating Buttonbush
Buttonbush can easily be propagated through stem cuttings. It is best done in the spring when new growth appears. You will need a small pot, moist soil, rooting hormone, and a sharp knife. Then follow these instructions:
How to Grow Buttonbush From Seed
Starting buttonbush from seed is simple. The seeds do not require stratification and can therefore be planted directly into the ground or in small starter pots. You will need moist soil and small pots. Then follow these instructions:
Potting and Repotting Buttonbush
Buttonbush’s large size makes it a bit tricky to keep in pots. However, young, small shrubs or dwarf varieties can be kept in large pots. If you choose to keep a buttonbush in a pot, choose container material that helps the soil stay moist, such as plastic or coated ceramic. Steer away from terra cotta, as this material wicks away moisture and dries the soil. Despite its adaptation to extremely wet soils, the pot should have drainage holes. If you choose a standard potting mix, adding a handful or two of perlite or sand will help to mimic the plant’s native soil conditions. Once the shrub fills the container, tip it on its side to gently slide the shrub out. Plant into a larger container or into the ground in moist soil. Keep in mind that potted buttonbush plants will need consistent watering since they do not have access to underground water sources.
Overwintering
Because these shrubs can handle temperatures that dip below 0 degrees Fahrenheit. they don’t need much extra care to survive cold winters. Potted shrubs should be moved to a protected area, For shrubs in the garden, simply apply mulch around the plant to help insulate the roots and retain moisture.
How to Get Buttonbush to Bloom
Buttonbush is known for its uniquely round, spiky flowers that appear in late summer, generally June through August. Though these flowers only last around 3 to 4 days, they offer plenty of visual interest. After the flowers fade, they produce small, brown, button-like seed balls that last through the winter. To encourage flowering, be sure to plant the buttonbush in an area that receives full sun. Give a slow-release fertilizer in the spring to encourage summer blooming.
Common Problems With Buttonbush
Buttonbush is known for its extremely easy care requirements and its hardy nature, meaning there aren’t many problems growing these plants. The biggest problem is too little water.
Leaves Falling Off or Wilting
Leaf loss or wilting is a sign of drought. Because these shrubs grow near sources of water or in very wet soils, too little water can be a big problem. Be sure to increase the amount of water the plant receives. Alternatively, you may want to relocate the plant to an area that receives consistently more water, such as next to a pond or river.
