The Portland Parks & Recreation website says "the more than 2,500 rhododendrons, azaleas, and companion plants in the Garden have all been donated by volunteers and interested individuals, or purchased with specially donated funds. Beginning in early spring and continuing into summer, they provide a magnificent display of color, giving visitors the opportunity to view many varieties rarely seen in the Pacific Northwest. During the fall, many companion trees add dramatic coloring. Spring-fed Crystal Springs Lake surrounds much of the garden, attracting many species of birds and waterfowl."
It really is a wonderful place to view resident and migrating waterfowl, see Red-winged Blackbirds hiding among the yellow iris, and of course - as the garden's name suggests - take a stroll through a very extensive collection of rhododendrons. The sheer number and variety of rhododendrons, azaleas, and other plants on display in the garden (most of which are labeled), make this a very interesting place to visit.
To see some more recent photos I took in the park, take a look at this post.
Info from the website:
April 1-September 30: 6:00am-10:00pm
October 1-March 31: 6:00am-6:00pm
Admission is free to all from the day after Labor Day through the month of February.
A $3 admission fee is charged between 10:00am-6:00pm, Thursday through Monday, March through Labor Day.
Admission is free for children under 12 and Friends of Crystal Springs Rhododendron Garden.