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Plantgasm - I love plants too much. By Derek Powazek.



plantbomb2Life in the city can get kind of bleak. Why not add a little extra life?

My wife loves to knit and I love to plant, so we decided to combine our passions to create these plant pockets. She knits them up, I fill them with soil and plants, and we’ve started leaving them around town.

Plant-wise, the trick is to plant them with things that are hardy enough to thrive in neglect. So in these photos you can see an Echeveria and an Aeonium – two plants that do quite well unattended in our climate.

The acrylic thread should pick up water from rain and fog, but there’s so little soil in them, I’m not worried about rot. And these particular plants are happy to grow in shallow containers, and fine to go for long periods of drought.

If people leave them alone, they could grow for quite a while just fine. I hope they bring a smile to the face of anyone who encounters them.


If you’re a knitter and would like to make one yourself, Heather’s posted instructions.

San Francisco’s Newest Hidden Plant Store

Back in March, I wrote about San Francisco’s Hidden Plant Stores. Now there’s another, and it’s a gem.

If you’re into plants and live in San Francisco, you probably already know about the monthly plant sales at the San Francisco Botanical Garden. But did you know that, just last month, the SFBG opened a small plant store? The Arbor is a small shop at the front entrance to the park (on 9th Avenue at Lincoln Way). They’re open every day from 10am to 4pm.

the arbor

All the plants are grown in the park, so you know they’re going to be happy in our climate. And it’s not the usual plant store stuff – there’s an eclectic mix. They’re much cheaper than other local plant stores, and all the money goes to support our wonderful local botanical garden. And the best part is, the Arbor is staffed with passionate volunteers like myself (I’ve been volunteering in the nursery for the last few months), so you can get helpful one-on-one advice from the people who actually grew the plants.

inside the arbor

So next time you visit the garden, stop by and check it out. Tell ’em Plantgasm sentcha.

Attack of the Spider Mites

Ever noticed tiny silk webs on the leaves of your indoor plants? You may have just assumed they were spider webs, but they may not be. They may be the webs of spider mites.

The difference is important because spiders (order Araneae) are generally good for your plants – they don’t hurt the plants and eat things that do. But spider mites (order Acari) are bad for your plants. They feed on the plant, sucking the life out. And if their webs get out of control, they can encapsulate plant entirely. Kinda impressive for bugs smaller than the period at the end of this sentence.

I’ve got a lot of tropical plants in the house, which are particularly susceptible to spider mites. My lovely wife shot some video of them with a great magnifying lens. Warning: this video will make your skin crawl. Watch it fullscreen for maximum creepiness.

How to know if you’ve got ’em: Tiny webs and yellowing leaves. Sometimes you can see them in bright light – they’re tiny, but quick.

What to do: Spider mites generally aren’t a chuck-the-plant kind of problem, but they are damaging and require vigilance. Here are a few things I’ve used to keep them in check.

  1. Hands. When you’re tending your garden, if you notice the webs, just reach out and wipe them away to keep them from getting established. Don’t worry, spider mites can’t hurt you, but use a paper towel you can toss or a cloth you can wash so that you don’t inadvertently spread them to other plants.
  2. Sprays. Most pesticides don’t work very well on spider mites. Some are so harsh they can hurt the leaves, which kind of defeats the point. Worse, some insecticides can make a spider mite infestation worse, because they can kill off predatory insects.

    If you’re going to spray, go for a horticultural oil spray or use Neem if you can stand the smell (I can’t). I’ve had some luck using sprays that contain Pyrethrum, which is a poison derived from Chrysanthemums. Be sure to test any spray on one plant before using it on all of them, just in case there’s a bad reaction. And generally it’s better to spray at night when it’s cool and the leaves are out of direct sunlight.

  3. Predators. I just tried this for the first time last week. The idea is, introduce another mite that eats spider mites, but does not spin webs or eat plants. Seems like a good idea. Unfortunately, I can’t say that it worked. I’ve been looking at the leaves under magnification all week and see no sign of the “good” mites. Maybe I just got a bad batch. I may try again. Either way, this is really only a solution if you have a ton of plants like me. It’s not worth it for a couple of houseplants.

The best thing you can do is make your environment inhospitable. Spider mites like hot, dry air, so mist your plants with plain old water frequently. The misting also makes the webbing easier to see – so wipe it off when you see it. And if you have a plant with a particularly bad outbreak, isolate it so it doesn’t spread.

Sorry for any nightmares that video causes.

Gardeners: Have you found any techniques to be particularly effective against spider mites? Please share.

Canna Bloom Timelapse

Beware of friends bearing bulbs! When my buddy Rob said he had a “few extra Canna bulbs” and offered me some, I said yes, of course. Little did I know I’d be going home with a huge box of them! There wasn’t enough space to plant them in my yard (until I remove some stuff, anyway), so they went into pots. Since then, they’ve sprung up with a vengeance. Here’s the first to flower.

This video is about two weeks, one shot every 10 minutes during daylight. It’s not quite in focus, but it’s still interesting. If you look closely, you can see life go on in the background: cats, dogs, grilling, and me wandering around in the back yard as I do.

Sex in the Garden: Tongue Orchids and their Dupes

You already know that orchids have pretty freaky sex lives. They depend on insects to carry their pollen from one flower to another, and employ a number of techniques to entice the bugs to visit. It turns out, some of those techniques are more successful than they need to be.

Take the Australian tongue orchid (Cryptostylis). The color, shape, and smell of its flower mimics a female wasp, so the male is attracted to it. Its pollinator is the Lissopimpla excelsa, or “Orchid Dupe Wasp.” (Imagine being named after your least complementary trait! Poor dupe.)

But here’s where things get interesting. In a study published in The American Naturalist in 2008, researchers found that most of these orchid-wasp pairings resulted in a “happy ending” for the pollinator. Yes, they found ejaculate in most of the flowers.

(Let’s just pause here for a moment to think about people collecting wasp spooge from orchids for science. Great job.)

The study claims to be “the first conclusive evidence of insect ejaculation in response to floral stimuli.” And they proved that these orchids have a far higher pollination rate than other orchids because of it.

This revelation led to some fascinating questions. If Dupe wasps are wasting all their valuable sperm in flowers, doesn’t that mean the female Dupes are left wanting? And wouldn’t that lead to an inevitable decline in the wasp population? And if these wasps are the only pollinators for the Cryptostylis orchids, how can they survive? Thankfully, nature always finds a way.

It turns out the Dupe wasps are haplodiploids. That means that, in addition to mating the old fashioned way, the females can also produce offspring all by themselves. When they do, those offspring are always male. So the orchids lure the male Dupes away, and the female Dupes just make more. Nature is clever, if not always kind.

Want more Sex in the Garden? Check out these fine posts from my fellow Bay Area Plant Bloggers, who all have sex on the brain today.

Photo from the study, copyright Esther Beaton.

I Always Feel Like Somebody’s Watching Me


My Pleiospilos nelii, aka Split Rock plant, is watching me.

Nasty, Nice Nasturtium

Speaking of plants some consider to be weeds, Nasturtium (which is actually Tropaeolum*) is a South American native that you can find growing everywhere in San Francisco. I’ve seen Nasturtium vines engulf whole bushes, spread over an entire park, and possibly abduct children. I pulled this guy out of a pot yesterday, where he sprung up almost overnight. You can still see the seed that started it all.


That’s the neighbor’s dog, Brutus, making a cameo in the background.

So Nasturtiums are nasty because they can be quite aggressive. But they’re also nice! Their leaves can get as large as dinner plates. In a dense thicket, they look kind of like lily pads in midair. The whole plant is edible, too. Their flowers have a crunchy pepper quality that makes them great salad toppers.

Personally, I love Nasturtium. It’s not their fault they thrive in their new environment. I came from another place, too. So I took the one in the photo above and planted him in his own pot. Everybody needs a place to call home.

corona heights north slope trail

* The plants I’ve always called “Nasturtiums” are actually the genus Tropaeolum. There is a genus called Nasturtium, but it doesn’t include them. So Nasturtiums aren’t Nasturtiums. See, this is why nobody knows plant names.

Masdevallia floribunda flowers

Masdevallia floribunda

It’s always exciting when an orchid flowers for the first time. When I got this little guy at the Pacific Orchid Expo, he was already mounted on a little bit of wood, but he wasn’t yet blooming, so this is the first time I’ve gotten to see his flowers. They’re adorably tiny.

If Loving Arum is Wrong, I Don’t Want to be Right

This post is going to have so many important disclaimers, I decided to put them first.

Disclaimer 1: Technically, everything in a state/city-owned park is owned by the state/city, and removing anything is either against the rules or outright illegal, unless you have permission, which I got from a gardener who told me I’d be doing him a favor removing the Arum since he considers it a weed (see disclaimer 2).

Disclaimer 2: The Arum genus is invasive in some places. Some gardeners curse the plant as a horrible pest. I’m not one of them.

Disclaimer 3: Arum, like most Aroids, are poisonous and contain calcium oxalate, which can irritate the skin, though I’ve never had a problem handling them.

Got all that? Okay, then.

I’ve been keeping an eye on a few clumps of Arum (probably italicum) in Buena Vista Park all year. I love their arrowhead leaves with silver lines, and their spathe/spadix flowers. I noticed them blooming way back in March. They’re a beautiful bit of the tropics here in California.


If their flowers are fertilized by flies and ground-crawling bugs, they form berries. They start out green, then turn yellow, and then finally red when they’re ripe. This is a signal for birds to come eat them, and in turn “distribute” (aka poop) the seeds elsewhere.

Buena Vista Park is where I walk my dogs, so it was easy for me to keep an eye on them. I first noticed the green berries in April, and they started turning red in late July. Four months is a long time to survive in a dog park.


When I finally saw red berries, I harvested some (see disclaimers!) and took them home to plant. Preparing Arum berries is like other Aroids, including Alocasia and Pinellia. Each berry contains a seed or two, which you have to pop out and wash. Aroid seeds aren’t viable for long, and they die once they dry out, so the quicker the better.


Once you pop the seeds out and wash them, you can plant them like any other seed. I put mine in a few pots, in normal houseplant soil, buried a quarter inch or so. If they sprout, I’ll plant them somewhere they’ll be appreciated, like my back yard, where the Buena Vista Park gardeners can’t find them.

They Are Hugging


I grew carrots for the first time this year and wasn’t sure how they’d do. So, I have to admit, I sewed the seed into the garden bed a little thick, and I never bothered to thin them out. As a result, the carrots aren’t exactly pretty. Still, they’re tasty. And this pair came out looking especially fond of each other.


Plantgasm is where Derek Powazek chronicles his botanical antics and misadventures. More.