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The Wetlands pages are now located on the Neighbors of Seahurst Park site, clicking the menu items will redirect you there.
This page lists many of the plants and animals that have been seen in Seahurst Park. If you know of something that isn't listed on this page please feel free to use the contact address at the bottom of this page to report it. Hopefully we'll be able to add photographs of many of them, either from the Park, or from other sources.
Most of the names are links that will take you to other sites with more information about that item.
Also see the separate section at the bottom of the page about Invasive Plant Species.
- Eastern Gray Squirrels: A Wikipedia page about them, and a WDFW page about all the types of squirrels in Washington, with maps showing their territory. Eastern Gray Squirrels are not native to the area, they were introduced about 1925.
- Douglas Squirrels
- Mountain Beavers
Details coming once someone spots them. We know they're there, they love wetlands.
Yes, snakes. Snakes are actually very common in Western Washington and are an important part of the ecology. But they're shy and don't want to be seen, so you are unlikely to spot one. They eat insects, mice, small birds, frogs and more. The ones I've seen in Seahurst Park haven't been big enough to eat much more than insects though. I think they've all been garter snakes, but I'm no expert.
The only dangerous snake in the State of Washington is the Western Rattlesnake, and it doesn't live in Western Washington, so you will not find a dangerous snake in Seahurst Park. The Washington Department of Fish and Wildlife has an excellent page about snakes.
Many of the names in this plant list came from a video on YouTube. You can see what they look like by watching the video. Maximum Millipede also has an excellent collection of photos taken in Seahurst Park online at Flickr. We'll be adding links to pages about the specific plants as we have time.
Bushes, shrubs and groundcover
Check King County's Noxious Weed list for a very complete list of invasive plant species. Unfortunately if they're in someone's yard nearby, they're probably in the park. Not all are technically classified as Noxious, they also list many common plants that are becoming problems as they spread.
The invasives can crowd almost everything else out. Even large trees will disappear. Invasive plants spread by several methods, and birds can carry the seeds for miles. They often grow during most or all of the year, giving them a big head start on the native plants. They have no natural predators in the area and aren't a good food source for our native species. In many cases the invasives grow so densely that native plants can't germinate and grow underneath them, so new trees and plants don't grow up to replace the ones that die. And we end up with holly thickets, ivy deserts, tangles of Old Man's Beard and impenetrable blackberry mounds.
The South African Agricultural Resource Council had a very good writeup of the problems that can be caused by invasive plants. It's not just a NW problem by any means.
It takes a while for invasives to build up to the point where they take over. At first you'll just see a few patches that spread slowly. But eventually there are enough of them that the coverage starts increasing rapidly. When they reach critical mass for seed generation, and the patches start growing together, they explode. Parts of Seahurst Park are being overrun with ivy and it's spreading rapidly. Holly is also spreading through some areas and a few sections have very heavy infestations of Old Man's Beard [Clematis]. Shorewood and Eagle Landing Parks are smaller and have been working at control for a couple of years so they're in better shape overall. All the parks (especially Seahurst) have some pristine areas that invasives haven't spread into yet and it's much easier to keep them out than it is to remove them and replant native species. A very large park in Portland has over 1,000 acres covered in ivy and they project that they need to hire a permanent crew of 70 to remove ivy at a cost of $1.5 million per year. The PI has an article from 2005 about problems caused by invasive plants.
Controlling invasive plants can be very difficult. The first priority is to prevent these plants from spreading into new areas. Once they're established they're hard to remove. Anything reasonable that prevents them from going to seed (or at least prevents the seeds from maturing) is an excellent step. And working at the edge of patches to keep runners from extending the boundary is very helpful. Once you stop the spread, then you can try to recover invaded areas. Some invasives can simply be chopped down for a few years and they'll die off. This works pretty well for Himalayan Blackberries. It's even relatively effective with Ivy. Others seem to grow more aggressively when they're cut back. This is especially true for Holly and Old Man's Beard.
Please do NOT cut holly trees unless you have talked to the Parks Department. Cutting these trees down just makes them sprout suckers from the stump and the roots.
This is a very short list of the most common invasive or problem plants in Seahurst Park, there are far more than this. I've included the Noxious Weed status for some of them, but the lists do not always agree. King County's Noxious Weed list is probably the one you should go by, but if it's included as a higher ranked weed on the State list, I've tried to link to that since it's an indicator of a more serious potential problem. The Washington State Noxious Weed Control Board has detailed information on the laws and regulations, as well as lists of regulated weeds. Remember that the term
weeds as used in this case can include tall trees.
English Ivy is a Class C Noxious weed.
Problem: Ivy on the ground will smother everything else. The roots are shallow and won't hold on a slope, increasing the risk of landslides. When ivy grows on fences and buildings the rootlets work their way into the surface and can cause damage. Ivy growing on trees blocks air and light from the trunk, and helps cause rot because the tree doesn't dry out. A thick ivy mat in a tree can add as much as 2,000 pounds of weight. When that gets covered in snow, or just wet, or catches heavy winds in the winter when other trees are leafless, it's even worse. Eventually the taller trees and plants fall, and nothing can grow back up through the ivy, so we end up with ivy deserts. Since ivy has no natural predators in this area, it runs rampant. The only ones who benefit from ivy patches are rats, for whom it's as good as a freeway system. If you have ivy, you almost certainly have rats. For humans, working with ivy can cause rashes and breathing problems.
Removal: When ivy on the ground is young it can be rolled up like a carpet and left to decompose. Pull the roots under the last section, trim the edge of the roll to free it from the ground, then roll it back onto a cleared section. If possible turn the pile occasionally to prevent the bottom of the pile from rerooting. On steep slopes remove ivy in alternate sections to reduce the potential for erosion. Always be careful to work around any native plants so that you don't damage them.
It's effectively impossible to remove ivy from trees once it's established. But you can kill it and let it drop off the tree. The best way to do it is to remove the leaves from the stems from the ground to as high as you can safely reach. Then, starting at shoulder height, cut all the vines that are growing up the trunk. Pull those vines off the tree, peeling them down towards the ground. Do not try to pull vines out of the upper tree, you could pull down branches or even a hornets nest. If the vines are small enough pull them out of the ground up to 6 feet away from the trunk. If they're too large [they can be 6 inches or more in diameter] cut them off as low as you can. They'll grow back into the tree, but it will take a while. Always wear a long sleeved shirt, long pants, boots and gloves. Coming in contact with the leaves can cause rashes for some people, and even breathing the dust from them can cause problems, so consider a dust mask. See IvyOut.org for more detailed information about removing ivy. Another site with good information is Ivy Out. I have a photo album showing the results of clearing a group of trees of ivy.
Control: Ivy spreads by runners and seeds. The runners can be pulled out of the ground, rolled up and left to dry out. Ivy only goes to seed when it's growing vertically, so the most effective way to control it's spread is to kill it in trees, and trim it on fences and walls once it flowers but before the seeds mature so that they don't spread the problem. Like with most of our worst invasives, birds eat the berries and carry them away to start a new patch of ivy in a whole different area. Ivy berries are ripe in early spring. King County has a lengthy page on English Ivy.
English Holly King County's Dec 2006 Weed of the Month It is a Weed of Concern
Please DO NOT cut down holly trees. We have hand tools that can pull out holly trees as much as 2 1/2 inches in diameter. But many have been cut in the past, then suckers grow from the stump and the roots resulting in a cluster of holly trees and bushes. A single large tree is much easier to deal with than a cluster of smaller trees that are all connected. We're working on getting them all eventually.
Problem: Holly spreads very aggressively and creates impenetrable thickets that eventually crowd out everything else. Holly will grow up through almost anything, but once holly gets established nothing will grow up through it. We recently cut down and hauled away a large, berry covered tree. The tree was about 30 feet tall and covered a circle about 25 feet in diameter. Once the holly was removed there was absolutely nothing growing underneath it. Holly bushes send out runners underground that will sprout into new bushes. Every branch that touches the ground firmly will put out roots. These two methods combine to create large, dense thickets of holly.
Removal: Small holly bushes may be pulled out by hand. Weed Wrenches work very well for larger plants. If the soil is loose and wet you can pull out trees up to 2 1/2 inches in diameter [with the largest weed wrench] without causing much disturbance to the soil. If the soil is dry or the tree is too large then you need to treat it. You can do it manually by cutting down the tree, and any associated plants, then aggressively going after any regrowth until the roots eventually die. Or you can treat it with poison. Holly leaves do not absorb herbicide well, so treating them is not very effective. The best way is to frill or girdle the trunk and paint the herbicide on the trunk using a small brush. Or the tree can be cut down and the herbicide painted on the freshly cut stump. The cut must be fresh.
Control: Only female holly trees produce berries. If you know of a holly tree that has berries, tell the Parks Department where it is so that we can treat it in the summer so that it dies completely. If a holly tree is loaded with berries, and it can be cut early in the fall, we can leave at least a 4 foot high stump so that it can be re-cut in the summer and treated. If the branches with the berries can be cut before they ripen, the branches can be left to rot as long as they're not in good contact with the ground. Berries ripen in late winter/early spring. If they're too ripe to leave, we try to haul them away.
Please be careful not to confuse young holly bushes with our native Low Oregon Grape and Tall Oregon Grape, they can look very similar. The most distinctive difference is that the leaves on Oregon Grape are directly across from each other on a branch, where holly leaves are offset.
Various Laurel trees
Many species of laurel have been used as ornamental tress. Some are particularly suited as hedges because of their aggressive, dense growth. But that also makes them a real problem in the park. Controlling laurel is very similar to controlling holly except that laurel flowers in the spring instead of the fall. The berries ripen in the summer. Laurel is harder to pull out of the ground because it has larger, heavier, wider roots than holly. Pulling anything much larger than a seedling causes a lot of soil disturbance. Laurel may be controlled by cutting repeatedly over a period of many years if it hasn't spread too much. The most common ones known to be in Seahurst Park are English Laurel which is a Weed of Concern in King County and Portugal Laurel which is not listed. English Laurel spreads very aggressively by several methods including roots, branches that touch the ground, and seeds. Portugal Laurel does not seem to spread as aggressively in it's immediate area, but there are large trees deep in the wetlands area of the park.
Spurge Laurel was King County's February 2007 Weed of the Month. It is a Non-designated Class B noxious weed in King County and a Class B Noxious Weed on the State list.
This relatively new and unrecognized invasive is present in Seahurst Park. The good news is that it's slow growing. The bad news is that birds and rodents spread the seeds far from the point of origin, and all parts of the plants are poisonous to humans, dogs, cats and many other animals. Handling the plant can cause a rash so you need full protection when working with it. Once established it's very hard to get rid of. The State Noxious Weed Board lists some control methods, along with other information.
Himalayan Blackberry was King County's October 2007 Weed of the Month. In 2009 it was added as a Class C Noxious weed on the updated State Noxious Weed list [PDF version] along with Evergreen Blackberry.
Small vines can just be pulled out of the ground if you have a pair of good gloves. Please be sure you're not pulling up the native Trailing Blackberry which also grows in the park. Larger blackberry vines can be cut off near the base and the vine will die if it hasn't rooted further out. Just doing this will slow it's creeping spread and prevent the vines from going to seed, which stops it spreading via birds and animals.
The larger vines often grow in clumps once they're become established and these clumps of root ball can be dug out of the ground. Often the hardest part is getting to them without being ripped to shreds. I start at the edge of a thicket or mound and smash down the pile of old vines until I can reach new growth. The old dead vines simply break into pieces and fall to the ground. Be careful not to damage any native plants while doing this. A long handled shovel works pretty well, or even a small, heavy log about 8 feet long that you can stand on end then drop on the pile. As you get further in and can cut the large green stems the pile will continue to collapse as it's support is removed. I cut the stems about a foot above ground so that there's something to work with when digging them up. Long handled loppers will extend your reach. Even better is a pole saw/lopper that can let you reach as much as 10 feet into a mound and cut vines off at the base.
Clematis vitalba (Old Man's Beard) Class C Noxious weed.
This plant has the potential to be more invasive than almost anything else in the park at the moment. It grows many feet per year, spreads aggressively by several methods, chokes out trees and plants, grows as much as 100 feet up into trees, and ends up creating a dense mat of vines along the ground that nothing else can grow up through. It flowers in the summer, and seed heads set in the fall, lasting through the winter. The King County page has information about how to control it. See this 1999 Noxious Weed Board write up for more technical information.
Herb Robert is also known as Stinky Bob, and there's a reason for that. Class B Noxious weed
As a good example of how difficult it can be to classify introduced plants [this one came from Europe] it's listed as Threatened or Endangered in 3 States that are trying to protect it, and an invasive in Washington State. Stinky Bob must be pulled and removed from the site because it will reroot from any parts that are left in contact with the ground. It should be disposed of in the garbage, not the compost. Stinky Bob is rapidly spreading through the park.
Canada Thistle Class C Noxious weed
The Noxious Weed Control Board has an extensive page about Canada Thistle. It spreads aggressively by root and seeds. Biological control is available according to King County.
Creeping Buttercup Not classified by the USDA, but is a Weed of Concern in King County.
Creeping Buttercup originated in Europe is now found in most of North America. It spreads aggressively by a number of methods, adapting it's method to the conditions. It will crowd out other species, but needs good light to grow, so it's mostly in open areas and along borders of woods. It's very difficult to control, seeds can be dormant for up to 20 years, and it comes back from any part that is left in the ground. Click it's name above to be taken to King County's page about it.