Summer weeds in Arizona

Pigweed time in the desert! About a couple weeks ago, we left the hose on too long, and the irrigation waters burst through the berms, spilling water all around the garden, giving a good soak to all that bare ground.

It is amazing: everywhere the water spilled, pigweed is growing now. Pigweed is quite distinctive because of its pink/purple underside.

Its purple hue gives it away: just like its magnificent large and purple "tame" cousin, grain Amaranth, pigweed is in the amaranthus family. The two common pigweeds are "careless pigweed" and "tumble pigweed". My advice: get the pigweed while it is young.

As it gets bigger, pigweed stems get really tough, making them hard to tear down or tear out later. This is especially true of the "tumble pigweed".

Not to be confused with the Russian Thistle, which is the true "tumbleweed".

I keep my main gardening area bare ground, so I can just scrape a hoe over the topsoil, killing them while they are seedlings. I just leave them there to decompose on the ground, which has resulted in a nice layer of topsoil as well.

The common purslane remains soft as it grows, so it is less of a nuisance later. Sometimes I will even let it grow quite big for awhile, letting nature provide me with some good compost biomass.

The "prickly lettuce" weed will be big and seed-headed now, if it survived as a garden volunteer from your spring planting.

Lots of "puncturevines" will pop up in your watered areas now too. As you can tell from the name, you really don't want to let "puncture vine" mature. They produce those "sharpy thorns" that make your kids cry when they step on 'em.

The UA book has this to say about "puncturevine":

"It is abundant, one of the most obnoxious weeds in southern Arizona, and is found throughout the state, principally in July and August. Each plant produces innumerable burs ... Home owners and their dogs probably dislike puncturevine more than any other weed because the stout spines can easily penetrate shoes, bicycle tires, and dogs' feet."

If you have an Palo Verde or Palm trees nearby, there is a good change you are getting tons of their seedlings pop up as well. Rip the Palo Verde seedlings out quick. As soon as they get just a little big they get barbs all over 'em.

Winter Weeds Blooming and Seeding

I love winter weeds. I have the most beautiful winter front lawn thanks to 'em. I call it clover, but I really have no idea if it is a true clover or not. Whatever it is, it makes the nicest most soft lawn. It is coming up with these pretty little yellow flowers right now. (I love it now, but it will produce these nasty sharp pointed seed pods later.) Here it is:


And this weird grass stuff, that if you let it grow, is more like sorghum or wheat stalks. This stuff is just awesome! I am totally going to harvest its seeds this year. If anyone knows what it is actually called, let me know. Here are some pics:

Dealing with Weeds and Grass

Everything got massive this week. The spring heat, I guess. The radishes, the lettuce, the peas, the weeds, everything! It like doubled in size overnight. Crazy.

I am harvesting the weeds for my compost pile. I am also letting it grow, a natural green manure crop to be tilled under in a couple weeks.




It'd be cool to identify these little buggers. They look like nasturtium leaves, except with ragged leaf edges instead of the nice round ones of the nasturtium.

The bermuda grass, now that is another story. That stuff will take over your area, any area that is watered, in summer. Years ago I used them to my advantage, keeping tomotoes going through August by letting them become a ground cover to keep the garden floor cool and moist as I irrigated every day. The downside is, all that work you did is totally undone, as grass has totally colonized your garden again. I am a big fan of bermuda grass for a lawn, but it is tough to garden with that stuff around.

This year, I am just tilling it under. I am doing an experiment to see how well that works. In a couple beds, I am just tilling, but in a couple others, I am tilling then running through the loose soil by hand to remove as many of the cut-up roots as possible. I honestly don't know how much of it will survive the tilling process. I'd love to say, none of it, but more like, all of it.

That stuff is tough, and the underground root structure is incredible (as you can see in the picture). You could look at a bare patch of dirt and think you were clear, but underneath, its all grass roots, just waiting for a drop of moisture. Luckily, it doesn't go much deeper than 4-6 inches, so a tiller is enough to thoroughly shread the root structure.



When getting rid of it by shovel, here is a nice trick: Get the spade under the roots, then just dump it upside down on the ground. Don't try to remove the roots from the dirt right away, the moist soil just clumps around the roots. Wait a day, till it has dried a bit, then step on the clumps. The soil just falls away, leaving the big nasty roots sitting there on top. I gather them up and burn them at that point. Mwah ha ha, revenge at last!