I took this picture on March 26, 2011, a year when there was a lot of rain and the river almost flooded. Hard to believe now when we haven't seen water in the river for two years, but that year it came almost up to the water's edge near the fence you see below.
As I walked to the bench to take the above picture, the poison hemlock and prickly milk thistle were up to my calves and I had be be very careful not to get scratched. It was so high, as you can see, the poison hemlock grew right through the seat of the bench. That bench is not on the ground as it appears to be. Its seat is at normal height for park benches. Who would want to walk over to that bench to sit and look at the river?
Unfortunately, in other parts of the park, along the paths, the poison hemlock is growing over my head, though most is only waist high. Closer to the riverbed on the south end of the park, there is poison oak next to the last access path to the river. One has to be careful what one touches there.
I'm not sure if the city just wants to keep the park wild for the sake of maintaining a wilderness area or if they are just not willing to spend maintenance money. Weeds are everywhere but the ball diamond and the paths themselves. Maybe the city just can't afford weed abatement and the hauling away of dead tree branches in the middle of the park as they fall from trees. I suspect the city gets grant funds to build the parks and trails, but not to maintain them.
Meanwhile those walking through the park just have to be aware of the poison weeds and hope lightning or smokers never set the dead wood by the river ablaze. If the park catches fire some dry season, the nearby residents will need gas masks to protect their lungs from burning poisonous plants.
Poisonous plants are everywhere in the North County. It pays to be able to recognize them and understand what they do. If you want a delightful read on this subject, try Amy Stewart's book below. She is an amazing writer and I've read this book and a couple of her gardening books, as well, and loved them. Wicked Plants is not a field guide, though. That's why I've suggested a highly rated field guide to poisonous plants as a supplement to it. Treat yourself to one or both today. If there's one thing I've learned, it's that having a good set of reference books around when you need them is very helpful.
Wicked Plants: The Weed That Killed Lincoln's Mother and Other Botanical AtrocitiesThe North American Guide to Common Poisonous Plants and Mushrooms