If you've sown your desert wildflower seeds over the past month or so, and given them a bit of water, they should be germinating and sprouting about now. Take a look around the garden and you'll find all sorts of little green bits poking their heads up.
But, as the poet says, not all that glisters is gold. In the Desert Garden right now, not all that is green is good. Many of those sprouting plants are, in fact, weeds.
The conditions that favor wildflowers also favor annual weeds, and it can be difficult to distinguish between the two when they're in the seedling stage. Our goal with weeds is always to pull them while they're small, and the amount of time and effort needed to cull weeds when they're new is but a fraction of the work it takes to get them when they are established.
The only way to get rid of the weeds while keeping the wildflowers is to learn what each looks like when it's in the seedling stage. That's not as hard as it sounds; as with much of gardening, it's really just a matter of attention to detail followed by a little practice.
To get you started, I've appended some photos of several common desert wildflowers and several common weeds, each in the seedling stage. Click on any picture to view a larger version. Some of the photos are a bit blurry, but it was early in the morning and I'd consumed prodigious amounts of coffee.
Wildflower: Desert Marigold. It's a fuzzy photo, but then it's a fuzzy plant. The first (seed) leaves are easily mistaken for a weed but the first true leaves are silvery and pubescent. Again, note the palm seed for scale.
Wildflower: Desert Bluebell. Another distinctive wildflower seedling, the Desert Bluebell tends to have very small dark, almost purplish, spots on even the seed leaves. Once you spot a few of these, you won't confuse them with any other plant.
Weed: Bur Clover. This is an unpleasant weed, forming little spiral burs, actually seed cases, covered with very sharp spines. These burs are painful to step on and the number-one most likely things to get stuck in your dog's pads. Note that the seed leaves are elongated ovals, the first true leaf is a one-leaf clover, and the second leaf is a three-leaf clover. These seed leaves are easily confused with a wildflower, so it's best to wait until you see at least one true leaf before pulling.
Wildflower and Weed: Scarlet Flax on the right, and Bur Clover on the left. Note that the seed leaves (lowest pair) on each of these plants are very similar. As noted above, wait for some true leaves before deciding to pull or keep.Weed: Cheeseweed. Perhaps the most distinctive seed leaves of all, these are heartshaped on thin petioles. Pull these when you see them; they are a bear when they get bigger and they re-seed fast.