When is the best time to trim this plant back? It’s gotten so high!

Question

Hello and help! When we had our backyard professionally landscaped a couple of years ago, they planted three what they told me were “astilbe” plants. The plants took root wonderfully but now are so tall and wide they’re just taking over. I was wondering about when and how I could trim them back. I looked online for information about astilbes but all I found were smaller flowering plants. I’m totally clueless about this so would appreciate any help you can give me! I don’t want to accidentally kill the beauties! I’ll attach pictures of the plants from now and when they first were put in.

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Answer 1

There are different varieties of astilbe, with different heights.

https://www.gardeningknowhow.com/ornamental/flowers/astilbe/types-of-astilbe.htm

The best time to prune is after the flowering cycle. Do a light to moderate height reduction by selective shaping. Don't take more than 25% of the foliage at one time.

https://www.gardeningknowhow.com/ornamental/flowers/astilbe/growing-astilbe-plants.htm