The Innocent Weed

Credit: Image courtesy of KOPTERVISION

Filoli is covered in a carpet of colorful blooms, but what do Filoli’s horticulturists see?  Weeds! As much as we soak in the beauty of the Garden in spring, we aim for perfection and we’ve trained our eyes to spot enemy invaders. If you’re spending time in your garden or local parks right now, you too are seeing the eruption of weeds brought to us by California’s winter rains and spring’s warming temperatures.  

Emerson described a weed as “a plant whose virtue has not yet been discovered.”  While some weeds will test me, I will try here to provide a friendly introduction to some of our common weeds at Filoli. When you see them at home, say hello – or give them a sly smile and then yank them!

Popweed aka Hairy Bittercress (Cardamine hirsuta)

Looks innocent enough – and then it’s everywhere.  Disturbed moist soils (as in vegetable and flower beds) are popweed’s favorite hangout. The joy of popweed is this: if you get to it before the seed develops and “pops” then you can easily eliminate it with a light tug or by solarizing. Once those seeds are popping, you’ll hear and see them – then look forward to future meetings with popweed.

Petty Spurge (Euphorbia peplus)

Petty Spurge, like other Euphorbias, has a white irritating and poisonous sap that will help you to identify it. Like popweed, pulling petty spurge before it produces seed offers gardeners a great satisfaction. The greenish yellow flowers are not very showy but they are distinctive. Once you’ve learned to spot them, you can easily pluck this weed, roots and all, from shrub and flowerbeds.

Cheeseweed (Mallow parviflora)

Respect Cheeseweed for its strong taproot. In early spring it could be mistaken for a geranium but by summer it will be 3 feet tall and that taproot will firmly anchor it to the ground. Pull it now while you’re still a match for it!

Buttercup Oxalis (Oxalis pes-caprae)

Oxalis has a shamrock leaf and a bright yellow flower just in time for St. Patty’s day.  This weed has made itself at home on the coast where it competes with natives and is a real menace. It reproduces by producing tiny bulbs that hang around in the soil and sprout again after you’ve pulled the weed out. A small patch of oxalis can be successfully eliminated by repeated pulling – you can do it! Oxalis is edible and deliciously sour – it contains oxalic acid so don’t overdo it.

Do you have an unknown weed springing up right now?  Master Gardeners are working remotely to help you solve your tricky plant and pest problems.  

Much as we horticulturists might grumble, we thank the weeds for bringing us Filoli’s wonderful garden volunteers. Happy weeding!

Kate Nowell has been Filoli’s Horticulture Manager since 2015.