Removal of Ivy, Holly, and Laurel Under the Forest Canopy
In areas of the park under the forest canopy, success consists of what is not seen – ivy, holly, and laurel. It won’t last forever without ongoing restoration (see below), but for now, it’s a pleasure to walk most of the forest trails and enjoy the native trees, shrubs, and forbs without the glaring presence of those three evergreen invasives.
The ivy in this area once buried everything beneath a tangled mass of vines three feet deep. Cleared in 2017 and re-weeded in 2019 and 2022, the naturally regenerating native shrubs and forbs are beginning to fill the understory.The ivy, holly, and laurel in this area were removed in 2012 and re-weeded in 2017.
Installations of Trees and Shrubs
Most of the one-gallon trees and shrubs installed in the past have survived and are growing despite the weeds colonizing the ground around some of them and the lack of irrigation through this past dry season.
Shore pines and Sitka spruce trees installed in April of 2021 continue to grow amidst a ground cover of native Trailing blackberry and invasive Creeping thistle.This Shore pine in a sunny edge has not been deterred by an invasion of Sheep sorrel.This Douglas fir in a sunny edge has now survived three dry seasons, the latest without irrigation.I have hopes that Grand firs, being somewhat shade and drought tolerant, will prove to be viable options for installation in aging deciduous forests. This one is doing fine, but deer have eaten a few that we planted.This Western redcedar was planted in a grove of invasive Sycamore maples in 2012.A fairly dense planting of bare-root shrubs and rescued Sword ferns were installed in this site after clearing Himalayan blackberry. Though the site is now filling with invasive forbs, the shrubs and ferns are doing well.Red-Flowering currant is beautiful in the spring and the fall, grows quickly in sunny edges, and adds biodiversity.
This dense installation of Sword ferns from 2018 has remained essentially weed free.Fringecup is an easy rescue plant that can effectively fill small gaps.Wild ginger can form a lasting ground cover in shady areas.Oregon Grape and Salal slowly spread via rhizomes.This dense installation of Oregon Grape and Salal was maintained with selective hand weeding for a decade and has only recently begun to effectively deter weeds.Inside-Out Flower has spread nicely in one area and provides some fall color.Beach strawberry is surprisingly persistent in sunny edges, though without ongoing, selective hand weeding, it can be overrun by weeds, like those popping up in this picture.
Failures – Efforts Without Lasting Effect
Clearing too Much Ground Without Making Dense Installations of Native Plants
In just one growing season without weeding, Herb Robert, Creeping buttercup, Wall lettuce, Nipplewort and other invasive plants have proliferated in some areas, especially along sunny edges, and in areas that were overcleared without dense follow-up installations.
Creeping buttercup and Herb Robert have quickly spread into this unmaintained weed break between the forest and turf.Herb Robert continues to grow rampantly, even in spots where it was removed year after year. Only ongoing, selective hand weeding can keep it under control.This Herb Robert is blooming in December! If it wasn’t so invasive, it might be considered beautiful.Wall lettuce in unmaintained edges goes to seed and spreads thousands of seeds. My time spent removing Wall lettuce and Nipplewort would have been better spent working on invasive trees (see below).Even dense plantings don’t work everywhere. None of the dozens of installed ground cover plants survived near this trail junction.Hedge bindweed grows such persistent rhizomes that the best we can hope for is to pull the vines every single growing season to keep it from overtopping plants.Once Moneyplant becomes established, it is very difficult to eradicate.Most of my efforts to eradicate Broom by pulling were evidently futile.Clearing only part of a patch of Himalayan blackberry doesn’t work without a maintained weed break. These recently-installed Douglas firs will soon be buried by runners.
Invasive Trees That Get Too Big to Remove
I wish that I had been more persistent in removing invasive trees when they were still small enough to extract with a weed wrench or cut down with a six-inch folding hand saw.
Norway maple leaves litter the ground – pretty to look at, but unfortunate.
Without Ongoing Restoration, Ivy Will Return
Ivy plants reemerge within a year if some of their roots are left in the ground.A few new ivy plants emerge almost anywhere, the likely result of seeds deposited by birds. The same thing happens with holly and laurel.
