It's mid-July, and the Yonkers metro area is in the early stages of what's projected to be a week-long heat wave. I've been lucky, I've been working the graveyard shift, so it's relatively cool when I am out-and-about on the job. While I don't really thrive in the heat, it's wonderful for purslane, a subject which I blog about WAAAAAAY too often.
This morning, in the relatively cool 7AM hour, I picked a good sized bag of purslane in one of the on-site gardens. Purslane does extrememly well in hot conditions because it can switch from using typical C3 photosynthesis using the Crassulacean Acid Metabolism method. In wet periods, the stomata of the plant are open, and photosynthesis occurs using the C3 carbon fixation process, which involves a loss of water due to transpiration of up to 97%. During dry periods, the purslane plants can switch to CAM carbon fixation- the stomata are closed during the day, but open at night to take in carbon dioxide. The carbon dioxide that is taken in during the night is stored as malic acid, so that photosynthesis can occur the following day. In the hot, dry months, purslane can take over a garden. As commenter "Cebtoo" wrote in response to commenter "GREENGIRL" question about how to grow purslane on the "Almost Turkish" blog put it:
To GREENGRL: Try to grow something else. Water once a week lightly. Everything else will die but your purslane will thrive with or without fertilizer, in sun or shade. Once you get some growing, break it up with a hoe. Spray it with broadleaf weed killer, it loves it. That's been my approach for years here in San Antonio and probably could grow 500 pounds or so in 100 square feet if I let it run wild.
My morning-picked purslane should be pretty strong flavored, being chock-full of malic acid, but I love the stuff. One columnist asks "weed it or eat it?" My answer to that is "YES!"