The plant information tags at nurseries, list the size of trees and shrubs at 10 years old. To insure you allow healthy space in your garden, do further research to find the actual size at maturity.
Plants in the Pacific Northwest may grow 15 to 20% larger than other areas!
For instance, the Western Sword Fern (aka Polystichum munitum), a Pacific Northwest native, is usually described as 3′-4′ wide and tall and is a popular “tough” fern. Yet, when growing in its favorite habitat – dappled shade, moderate rainfall, as an understory plant beneath Douglas Fir (Pseudotsuga menziesii) trees – Sword Ferns frequently reach 5′ tall and 7′ wide or even larger!
And those Douglas Fir trees that Sword Ferns love to grow under that start out so cute and tiny? Well, at 10 years of age they easily reach 25′ tall, by 40 years, can exceed 125′ feet, and very old trees reach 300′ tall!
A great place to see some mature plants and how they grow in our area is at Naturescaping Wildlife Botanic Gardens at 11000 NE 149th St., Brush Prairie, WA. Many of the plants are labeled and there is good connectivity so you can read more about the plant while you stroll through the gardens, too!
Wildlife Botanical Gardens web site: naturescaping.org
[Image: B.R.; Hint: T.J.]