This is a good time to talk about weeds. The rain has been very generous this year, bringing lots of seedlings along with it, but it can be hard to tell which are weeds and which are plants we want to keep. When sowing seeds in the ground, the safest bet is to germinate a few in a pot so you know what the seedlings look like. If that’s not an option, getting to know local weeds is a good idea.

TPF’s former director of horticulture, Madena Asbell, put together a lesson on seedlings and most of these pictures and some of the text are from her. Thanks, too, to Jacob Goetz for sharing seedling pictures!

Bad Weedling: Mustard (Brassica species)

Mustard covers much of our wild lands and is a very prolific weed. It’s best to remove mustard wherever you can.

 

Mustard seedling, by Madena Asbell

Mustard in early flower, by Madena Asbell

 

Bad Weedling: Red-stemmed filaree (Erodium cicutarium)

These low-growing weeds have naturalized throughout the state.

Red-stemmed filaree seedling, by Madena Asbell

Red-stemmed filaree in flower, by Madena Asbell

 

Bad Weedling: Russian thistle or tumbleweed (Salsola species)

In addition to being a noxious weed, Russian thistle is a fire hazard so it is best not to let it establish on your property.

Russian thistle or tumbleweed seedling, by Madena Asbell

Russian thistle or tumbleweed seedlings, by Madena Asbell

 

Good Seedling: California poppy (Eschscholzia californica)

Poppies are fairly easy to recognize. The very first “leaves” to emerge (the cotyledons) are slender and forked. The true leaves that follow are bluish in hue and deeply divided like the leaves of a carrot.

California poppy seedlings showing cotyledons (with fallen manzanita petals)

California poppy seedling, by Madena Asbell

 

Good Seedling: Clarkia species

Clarkia seedlings can be recognized by the red veins and margins of the leaves on the plant on the right. Notice the weed seedling on the left. The leaves are narrower and serrated. Clarkia are a good example of how a desirable plant can become unwelcome in the garden (a weed, in other words). Most gardeners find they have to thin Clarkia seedlings or they become overrun with them.

Clarkia seedling, by Madena Asbell

 

Good Seedling: Wishbone or four o’clocks (Mirabilis laevis)

This California endemic is native to Los Angeles County and puts on a wonderful spring bloom.

Wishbone or four o’clock seedling, by Madena Asbell

Wishbone or four o’clock in flower, by Madena Asbell

 

Good Seedling: Yarrow (Achillea millefolium)

Yarrow seedling, Ohio State University Weed Guide

Yarrow seedling, by Weeds of Australia

 

Good Seedlings

California buckwheat (Eriogonum fasciculatum) seedling, by Madena Asbell

Bladderpod (Peritoma species) seedling, by Madena Asbell

Chia (Salvia columbariae) seedling, by Madena Asbell

Lupine (Lupinus species) seedling, by Madena Asbell

California fuchsia (Epilobium canum) seedlings, by Jacob Goetz

Hooker’s evening primrose (Oenothera elata) young seedling, by Jacob Goetz

Hooker’s evening primrose (Oenothera elata) seedlings, by Jacob Goetz

Red monkey flower (DIiplacus puniceuIs) seedlings, by Jacob Goetz

California bee plant (Scrophularia californica) seedling, by Jacob Goetz

Seaside woolly sunflower (Eriophyllum staechadifolium) seedlings, by Jacob Goetz

 

Seedling or weedling?

Here’s where it gets hard: telling one from another. The tidy tips seedling on the left has bright green linear (long and straight) leaves with lobed margins (edges). The unidentified weed has lanceolate (lance or arrow-shaped) leaves with serrated margins (edges) and small purple spots.

Tidy tips (Layia species) seedling, by Madena Asbell

Unidentified weed seedling, by Madena Asbell

Russian thistle has needle-like leaves while California poppy has carrot-like leaves.

Russian thistle or tumbleweed seedling, by Madena Asbell

California poppy seedling, by Madena Asbell

Chia has deeply lobed leaves with a warty surface texture. Its petiole (leaf stem) is often light purple/red and its leaf texture resembles laciniato kale. Filaree has alternating leaflets attached along a greenish-yellow petiole (leaf stem). Individual leaflets resemble cilantro or parsley.

Chia seedling, by Madena Asbell

Red-stemmed filaree seedling, by Madena Asbell

Mustard seedling on left with a Phacelia seedling on right. Phacelia campanularia leaves often have reddish veins, margins and petioles (leaf stems). Mustards do not.

Mustard seedlings, by Madena Asbell

The leaves of grasses and blue-eyed grass (Sisyrinchium bellum, Iris family) look very much alike when very small. Seedlings of blue eyed grass will develop, flat overlapping leaf bases. The leaves of true grass seedlings do not form into a flat shape. You’ve probably seen enough unwanted grass seedling to recognize them in your sleep.

Blue eyed grass seedlings

Unidentified grass seedlings

 

Seedling or … seedling?

Sometimes it can be hard to tell one seedling from another. Poppy and yarrow both have finely divided leaves so color may be the easiest way to tell them apart. Poppy is much bluer while yarrow is “spring green”.

California poppy seedlings

Yarrow seedling, by Weeds of Australia

 

There are many more weeds that we could cover. UC Extention has a useful online identification guide for identification. Happy weeding!