Weed ecology

Late winter and spring are such busy times for gardeners! In my new garden, this has meant hours of weeding to get the soil ready for planting and to try to reduce the weed burden in future years. We have several insidious invasives that have much more to them than meets the eye. 

Oxalis pes-caprae 

has green above-ground clover-like leaves and attractive yellow flowers. They start growing in the late fall. Underground, sometimes more than two feet deep, are fat, opaque white tubers. Attached to the tubers are a few bulblets. Attached to the bottom of the green growth is a long filament at the base of which is an older bulb, covered in a papery brown skin. As the season progresses, more bulblets form seemingly everywhere and if you wait too long to dig them out, they will mature and fall off when you try to remove the plant leaving the beginnings of next year's weeds. 

I thought this was one of the worst weeds I could try to eradicate from a garden until I encountered False Garlic (Nothoscordum gracile). This plant is insane! It has long, grass-like green leaves growing from a bulb. Digging up the bulb, I often find 25? 50? tiny bulblets that have formed around the main bulb and fall off as I try to dig it out. More soil has ended up in the city compost bin than I would normally put there just trying to capture all of these tiny little bulbs. I've weeded an area, laid down cardboard, and returned in a week only to find hundreds of tiny little grass-like shoots growing from the left-behind bulbs. I have weeded the same areas 4-5  or more times this winter in an effort to dig out all the sprouting bulbs. All of this meticulous weeding has to pay off, right?! If it doesn't, I see more raised beds in our future. Of course, then you need to be super careful about moving soil around from one part of your garden to another or installing nursery plants with new weeds in the soil. 

From these two examples, I hope I've helped you understand how important it is to know the ecology of the weed you are trying to eradicate. The UC Davis IPM website has many of the most common weeds in the Bay Area and they are my first resource to learn more. Get in touch if you have questions about the weeds in your yard! 

Landscaping with natives: rewilding? ecological gardening?

Whatever you call it, incorporating native plants into your landscape design is essential if we want to help support natural systems. I've recently found some inspirational resources that are pushing me even farther towards native plant landscaping than I was previously inclined to. And that's after working in a National Park for 22 years, including at a native plant nursery, and being an avid hiker and flower-watcher. So if it's easy for me to be swayed by those showy blooms from other parts of the world, I can imagine that native plants aren't even on many people's radars! Calscape.org is a fantastic website that allows you to search by zip code in California and then narrow plant lists by sun, shade, water use, etc. The page for each plant gives you information about using that plant in landscaping! It's a game-changer. 

The California Native Plant Society's "East Bay Bringing Back the Natives tours" last spring were virtual, as was the keynote speech by Doug Tallamy. I encourage you to watch it. While Doug teaches and researches out of the University of Delaware, the talk was targeted toward California ecosystems. He recommends aiming for 70% native plants in your landscape and since 78% of land is privately owned, we all need to contribute toward supporting food webs. Each plant should be chosen for its ecosystem services, and even among natives, some are involved in more plant-animal interactions than others. These are the keystone species. Doug is an entomologist and his research looks at caterpillars' use of plants. Why? Birds eat TONS of caterpillars! If we want birds, we need to ensure the plants that grow their food are in the landscape. Also, learn which plants support specialist bees and plant for them (i.e. Sunflowers support 13 species of bees)

Doug's suggestions:

1. reduce by half the land covered by lawns 
2. remove invasive (non-native plants that displace native plant communities)
3. use keystone plants
4. build a layered landscape
5. if you need outdoor night lighting, use motion-sensing lights (ideally yellow LED)
6. preserve leaf litter
7. oppose mosquito spraying
8. reduce pesticide use
9. join your HOA and work to change rules that don't support native plants and animals

https://www.bringingbackthenatives.net/douglas-tallamy-resources

I've started making a list of native plants that support bees and butterflies and am working them into my landscape designs. Since I plan to grow so much food, I probably won't reach the 70% native goal, but I have visions of sunny wildflower meadows in my front garden. I have my eye on Salvias, sunflowers, and blue-eyed grass. We'll see what else gets added to my garden wish list! What are you putting on yours? 

Places to look for (and buy) native plants in the Bay Area (I will add to the lists as I learn about more nurseries):

http://www.baynatives.com/

http://www.eastbaywilds.com/

https://www.watershednursery.com/