Wow, that is a neat looking plant. I hear it when people come to visit the garden. Goats Beard is a wonderful plant. Once established it grows fairly quickly in the spring. The compound leaves kind of look like an astilbe, there is just more of them. The plant is in a mound shape that gets about 3 feet in my shaded garden. I've been told it can get to 5 feet with a bit more sun and moisture.
The creamy white plume-like flowers are a sight to behold. The plants are male and female, the males being more feathery flowers and more upright plants. Unfortunately until they flower there is no way to tell them apart. You really would not be able to tell in a mass planting any way. Goats beard would work any where you need a shrub but have a lot of leaves to clean up in the fall. Goats Beard dies down to the ground so you don't have to worry about cleaning tree leaves out of it like most shrubs. It is also a great backdrop plant for a woodland garden. I do have one at the edge of a walk and it works well as an edge plant there. It holds the bank in place.
Goats beard prefers moist soil with lots of organic matter but seems to tolerate a drier soil if watered until it is established. Along a stream bank would be a good home. If you are trying to get rid of invasive honeysuckle it would work well to hold the honeysuckle back. It is worth a try anyway as the root system is tough,
Goats beard is an insect magnet. If you need to do an entomology collection you can get quite a bit of it done by visiting to this plant. Insects use it for its nectar in the early summer. Aruncus dioicus is a larval host and or nectar source for Dusky Azure Butterfly. This makes it valuable in the pollinator garden.
Propagation is relatively easy from seed. The difficulty lies in knowing when the seed is ripe. The flowers turn green and then brown seed heads form. Just before they turn brown you need to harvest the seed head. I dry the head and plant before winter sets in. They will germinate in the spring. I tried to divide one once. You would need a jack hammer to separate that root ball. Much easier to grow from seed.
Goats beard flowers at the same time as Bowman's Root making it a good companion plant. Green and Gold at the base planted at least 4 feet away is also a great companion. Plant with spring ephemerals such as Spring Beauty, Virginia bluebells, and Toothwort. Put in White or Blue Wood Aster and Blue Stemmed goldenrod for the fall.
