Native Plants of the Issaquah Alps: Interview with Dan Hintz

Visitors to the Issaquah Alps are drawn to the trails for different activities, all of which take place within the backdrop of a forested escape outside of the city. While all of us enjoy immersing ourselves in the wooded Alps and enjoy the peace of the local flora and fauna, it’s easy to pass through this forested oasis without really looking at what’s around us. Have you ever wondered which trees, exactly, you’re walking under? Or forgotten your hiking snack and been tempted to nibble some berries beside the trail, only to question if they are actually safe to eat?

To learn more about the native plants within the Issaquah Alps ecosystem, I spoke with Dan Hintz, the Restoration Projects Manager for the Mountains to Sound Greenway and an expert on Washington-area native plants. Learn more about Dan--and his plant knowledge--below and take some of his wisdom with you on your next trip to the Issaquah Alps.

Bri: What is your relationship to the Issaquah Alps and the Issaquah Alps Trail Club?

Dan: I have been an Issaquah resident for over 2.5 years and have been working near the Issaquah Alps with the Mountains to Sound Greenway Trust for 5 years. I feel so lucky and privileged to be able to walk from my apartment to trailheads on Squak and Tiger Mountain. I visit the Big Tree on Tradition Plateau at least a few times a month and my wife and I love hiking the East Side trail on Squak Mountain where we have seen such amazing wildlife! 

I have learned more about IATC by attending forums, reading newsletters, and making connections with board members and staff. The history of conservation in the Issaquah Alps is so important to me and I want to do what I can to carry that legacy forward and connect more people with these beautiful mountains and forests. That being said, there is still much work to be done to restore these forests and make sure there are sustainable recreation opportunities accessible for all communities. I am excited to lead several guided hikes this summer as part of the IATC hiking program, with a focus on forest health. I look forward to finding more ways to help supports IATC’s mission. 

Bri: How did you learn about plants and how do you use this knowledge for fun and for work?

Dan: [Native plants] are a job, hobby, and passion. My role with the Greenway Trust is the restoration projects manager, which requires strong knowledge in both native and noxious (or invasive) plant ID. While we do some work in upland forests like the Alps, most of our projects are focused on habitat improvement along salmon bearing streams like Issaquah Creek. It is one thing to be able to identify plants, and another step to be able to understand their ecology and benefits or threats to our ecosystems. I studied environmental horticulture at UW so that is really the foundation of my knowledge, but like anything, it requires practice and constant learning (and re-learning). Right now in the heart of spring everything is so lush and beautiful, but I find myself having to work each year to remember all the beautiful forest wildflowers and other annual and biennial plants that emerge then disappear over winter. It is a pretty amazing feeling to walk through a forest and “know” plants by name. Makes you feel really attached to your environment. 

Bri: Can you give us an overview of the Issaquah Alps forest ecosystem?

Dan: The Issaquah Alps are obviously forested, but can vary quite a bit in their composition depending on elevation, aspect, and proximity to moisture from creeks and ravines. We also must remember that all of the Alps have been altered by timber practices over the past hundred plus years. Forest stand ages can vary a lot throughout the alps, and many areas may have less biodiversity with one dominant species of tree (often Douglas fir) coming back after timber harvests in dense, uniform age stands. While these are still issues we are working to improve, it cannot be overstated how amazing IATC and other partners have been at getting land into public ownership and keeping the landscape in the Alps from being too fragmented. The wildlife corridors between Tiger, Squak and Cougar are so important for wildlife. While we rarely see them, the fact that bear and cougar and other wild animals thrive in these hills is very special to me!

Bri: I love all the big trees in the Issaquah Alps. I’ve tried to identify them, but it’s difficult: to a non-expert, many species appear indistinguishable. Could you explain the main trees we’ll find in the Issaquah Alps forests?

Dan: I would say there are five dominant tree species in the Issaquah Alps. Three of them are evergreen (conifer) trees, and those are Douglas fir, western redcedar, and westsern hemlock. Douglas fir is probably the most common conifer and does really well colonizing distubred sites with more sun exposure (conditions common after timber harvests). Western redcedar prefers more shade and moisture and can often be found along creeks. Western hemlock is a later successional species that requires shade and lots of organic soil. These are the trees you often see growing on top of nurse logs and stumps. 

As for deciduous trees, the two most common are big leaf maple and red alder. There is also a bit of black cottonwood along creeks and wetter areas of the Alps. Red alder is a very important early successional species, and somewhat like Douglas fir, will colonize disturbed, sunny open areas, preferring more soil moisture than Douglas fir. Red alder’s are the “rock stars” of our native trees as the grow fast and die young (alders might only live 50-75 years while our conifers can live 500-1000 years or more!). Red alders also fix nitrogen from the atmosphere into the soil which is SO important for plant life. Big leaf maple also lives up to its name and has the biggest leafs of any maple trees on the planet. They are often covered in moss and licorice ferns. It is a great time of year to look at the Alps and see the darker green conifer trees along with the much lighter green of leaves just emerging on our Alders and Maples. I love to look at Tiger Mountain from a distance and ponder why certain trees are growing in certain locations. 

Bri: What about other plants? The Pacific Northwest has a lot of beautiful ferns, which to me make our forests look like the set of a dinosaur film. Could you walk us through what grows under the trees?

While there are hundreds of species of plants occurring in the Alps, there are some common forest understory compositions associated with our forest types. Our coniferous forests often have dominant understory species of sword fern, and/or a combination of dull Oregon grape and salal. These plants usually aren’t more than 3-4 feet tall, but can spread out and form large patches of valuable understory habitat. 

Then you get into some of our slightly more sporadic, but beautiful understory woody shrubs. In drier forest areas, the huckleberrys (there is a red huckleberry and evergreen huckleberry) are beautiful shrubs with very tasty berries. Red huckleberry also (like western hemlock) likes to grow in nurse logs. Thimbleberry is another flowering/fruiting shrub that likes drier, but sunnier edges of the forest. In somewhat wetter areas, you will see red elderberry, salmonberry, and one of the worst plants to have to bushwack through, Devil’s club. These are really to just name a few, the understory plant diversity in the Issaquah Alps is truly astounding, and I haven’t even mentioned wildflowers like trillium, starflower, large leaf aves, fringe cup, and many more I am still learning! 

Bri: Identifying edible plants requires skill and should be explored with extreme caution, but can we eat any of the Issaquah Alps plants?

Dan: I would say thimbleberry, salmonberry, and huckleberries are the most desirable edible plants in the Alps. You will start to see salmonberries here in the next few weeks. Almost all of our fruiting plants are edible, but how desirable they are can be debated. You can eat Oregon grape berries, but they don’t taste great (pretty sour) by themselves so are often used to make a jam (sugar makes everything taste better, right?). Stinging nettle is often a trailside nuisance to people who unknowingly brush against it and all the sudden have a stinging or burning sensation on their skin (it’s not poisonous and that feeling usually goes away within a half hour for most people), but it can be very tasty (boil off the hairs that cause the skin irritation first) and has similar taste and texture to spinach. It is also used to make teas and is known to have high levels of vitamins A, C, and K. 

Bri: I was scared to try stinging nettle pesto, but it’s really good! Which plants are truly poisonous and should be avoided?

Dan: The main berry you want to avoid eating is from our snowberry shrubs. They are the only plant you will find with white berries, which is a sign you should avoid them. I do believe they can be used in the right dose as a diuretic, but probably not something you want to experiment with on your own. Ethnobotany is such a cool field (use of plants for edible and other medicinal and practical purposes) and is something I still want to learn so much more about. 

I will add the caveat that while eating a few berries while hiking is maybe not that big of a deal along a trail in the Alps, you should follow land manger foraging rules and never go off trail to forage. Eating a wild berry is such a cool way to connect with nature, but we also must acknowledge and try to limit our impacts on these ecosystems. 

Bri: Sometimes plants that are beautiful or even tasy are actually invasive and cause a lot of damage to local ecosystems. Which invasive species should we be worried about in the Issaquah Alps?

Dan: While blackberry is often public enemy number one in most people’s minds, I would say the two biggest invasive species threats to the Issaquah Alps are English ivy and English holly. You do see lots of blackberry and scotch broom on the sunnier margins (we call this edge effect in ecology) of the forests (under power lines or edge of trails for example), they often don’t escape into forests since there is too much shade. 

Unfortunately, holly and ivy thrive in shady conditions. Ivy creeps along the ground, preventing our native species like sword fern, salal, and Oregon grape from establishing. It also really prevents conifers from germinating when there is a carpet of ivy under mature trees. This can potentially have really negative effects on forest regeneration. Ivy also climbs trees and can even topple them if left unchecked. Ivy creeps slowly in forests, but birds love to eat their berries, will perch on a tree and poop, creating new infestations. It is not uncommon to see one lone tree in the Alps with ivy growing on it, but very little present on the forest floor. Birds are great, but they are vectors too! If you know what ivy is and see lone little patches, it is great to rip it out! 

English holly is an invasive tree that is spread by rhizomes and also by seeds (birds like to eat the red berries and drop them like ivy). English Holly is really difficult to remove as it can come back from small root fragments. It is a rhizomatous species, meaning roots run underground and send up new shoots which look like new trees, but are actually all part of the same specimen (kind of like Aspen tree groves). English holly is also known to have allelopathic properties, which means it releases chemicals into the soil that can inhibit growth of native plants in the vicinity. Small holly trees can be pulled out, but large infestations are best treated with chemical injections, something volunteers are plugging away at on Tiger Mountain. 

Bri: I love plant biology, but I know very little about plant identification and have been trying to improve this skill. How could a novice plant naturalist get started?

Dan: I will be leading several hikes this summer (keep an eye on the IATC Events page for incoming info!) 

There are also chapters of the Native Plant Society that often have events and resources to learn more.

This is the best book: Plants of the Pacific Northwest! Great pictures, descriptions, and information on plant ecology and ethnobotany. I also like to use the iNaturalist app on my phone, which allows you to take pictures of plants and they will give suggestions of what you are seeing. 

Thanks Dan!