DryStoneGarden

golden mummies & aphids

Please excuse the rather unpleasant photo. Aphids are gross, but golden mummies are one of the best things I ever learned about IPM.

We’ve had a couple of outbreaks of aphids this spring, first with the lupine when it put out a big flush of new growth and now on our kales as they begin to bolt. Golden mummies are the brownish, mummified carcasses of parasitized aphids; wasps lay their eggs in the aphids and the larva eat the aphids from the inside, leaving the dried husks. If you aren’t familiar with them, click on the photo and you should be able to see the difference. In the garden, another way to tell the difference is that aphids move and mummies don’t.

When you see an outbreak of aphids, the presence of golden mummies is one sign that natural predators are present. Count the aphids and golden mummies on a leaf, and, if the outbreak includes at least 10 percent golden mummies, the natural predators will deal with the outbreak for you. Spraying would kill the natural predators along with the aphids and therefore be counterproductive, though aiming a spray of water against the aphids to knock them off (which actually kills a large percentage of them, while not harming the beneficials) is okay if you want to speed the process. 

In the photo, I count 14 golden mummies (mostly on the right, but three in the population of aphids on the left) and estimate about 100 aphids, so our IPM is working. Our earlier outbreak on the lupine was the same way, and it resolved itself without intervention.

ryan 4/22

Indian paintbrush

Indian paintbrush is one of my favorite native wildflowers to see hiking, and one of the more unusual plants in any of our gardens. It is a hemiparasite, meaning it takes nourishment from a host plant but also photosynthesizes for itself. To grow it, you have to germinate the seed and then put it in a pot with another plant and wait for them to join root systems; when I read about the process, it sounded like a huge pain in the neck. Now that it’s established, though, it’s really carefree, growing with an Artemisia californica in some of the heaviest clay soil we’ve ever planted in. The two plants have similar foliage, so you don’t notice the paintbrush for much of the year, but then the blooms pop out from under the shrub and carry on for a long time before fading back and going dormant for the winter.

We got the plant at the Watershed Nursery, the only nursery I’ve ever seen selling it, and, in our experience, the best source for natives in the area. East Bay Nursery and Berkeley Hort and Annie’s Annuals are all good for natives, too, but they mostly sell cultivars and their plants come from all over the state, not really “native” in the purest sense. The Watershed Nursery, on the other hand, sells Bay Area natives, grown here in the Bay Area from seed collected here in the Bay Area. If you want to plant the same plants that you see when you’re out hiking, it’s the nursery to go to.

The paintbrush came in a gallon pot with the artemisia, but the Watershed Nursery grows most of their stock in restoration tubes. Restoration tubes, if you’ve never used them before, have some advantages over the typical gallon pots you find in the typical retail nurseries. Compared with a gallon-sized pot, it takes less time for the plant to fill the narrow tubes with roots, so the plant will cost less while still getting its roots just as deep in the ground, and the plants haven’t spent as much time in potting soil, so they are quicker to adapt to whatever soil you plant them in. The tubes have vertical ribs to keep the roots from girdling, and they are open at the bottom so the roots air-prune instead of circling the bottom or heading back up to the top. You don’t have to spend as much time undoing a root ball, so you can plant a lot more quickly, and you don’t do as much damage to the roots, so the plants establish themselves almost immediately. The plants look small when you first plant them, but they often seem to explode out of the ground. I’ve recently been passing by several yards where we planted a lot of Watershed Nursery plants, and they’ve all been looking big and healthy and happy. They have a sale every year during the upcoming Bringing Back the Natives Tour.

The Kew seed slideshow has a cool photo of an Indian paintbrush seed.

Asarum caudatum, wild ginger

…you reach down to pick off a brown thing and realize that the brown thing is the flower. It’s actually a pretty cool flower, but probably best described as interesting but inconspicuous, as half of them hide under the foliage. I’m just glad to see the plant looking happy. I bought it as a 2″ stubby, and it was miserable for a long time, until I stuck the pot underneath our flagstone bench and ignored it for a while. It’s one of the few California natives that genuinely seems to prefer deep shade, just start it off in really good soil but then completely neglect it. It’s currently in the group of container plants beside our front door, a spot that gets about twenty minutes of direct sunlight during the entire year. (more…)

Eschscholzia californica maritima & Escholzia californica

I like this accidental side by side comparison of the coastal form of the California poppy, Eschscholzia californica maritima or Eschscholzia californica var. californica, and the regular California poppy, Eschscholzia californica. I put in the regular one two years ago and the coastal form last year. Both plants are perennial in our garden, so now we have both. I suppose growing together they could hybridize, but we deadhead pretty regularly and there are many blocks of houses and concrete between us and any “wild” land.

The regular poppy might be the better plant for most gardens–bigger and faster with larger blooms and that unique burnt-orange color–and it’s definitely more common in gardens, but the coastal one has its merits, too, and seems to be getting more popular. I say “regular” and “coastal,” but I’m pretty sure the coastal form is actually the native one for Richmond Annex where I live. In fact, the owner of Larner Seeds, where I got my seed, has a post on her blog that suggests that the prevalence of the more annual form around the Bay Area hills and throughout the state is the work of past generations of Boy Scouts, Sierra Clubbers, and other human seed dispersers, and that there used to be a lot more regional variance across the state. And apparently people are still doing it, James at Lost in the Landscape cites a recent re-gen project in the San Diego area that used the generic poppy instead of the locally native form.

The flowers of the coastal form have an interesting two-tone color, an orange interior fading to a bright lemony yellow on the outer parts of the petals, and they seem to vary a bit in size and coloring; the biggest coastal flowers are often as big as the smaller flowers on the annual form. In the wild I’ve mostly seen the coastal form looking like a woolly little blue-gray thing growing in dry mineral soil, but in the garden they get about a foot tall, and they’ve been quite willing to cover themselves in blooms during the spring and then keep producing sporadic blooms throughout the summer. Their small size works best for our small garden, so we’re thinking of pulling the regular ones this year, and going down to just the single form, the coastal one.

Eschscholzia californica maritima, coastal Cal poppy

ribes sanguineum & physocarpus capitatus

I didn’t get the greatest photo, but I find this juxtaposition pretty funny. First off, it’s a mistake on several levels. It’s in a planting outside a sub-development, and I’m sure that a landscape architect designed the planting with all Ribes sanguineum (flowering currant), but the contractor accidentally installed one Physocarpus capitatus (Pacific ninebark). There’s only one ninebark in the whole planting, and the two plants look similar when young so it would be an easy enough mistake to make, and there’s no way someone would intentionally plant this–it looks like Two-Face from the Batman series. There’s also no way anyone should have hedged these plants, but for some reason people seem to think it’s appropriate.

The mistake does make for an interesting, if slightly unfair, comparison. When they are not hedged, ninebarks have beautiful new foliage in the spring; the new leaves have almost the same effect as flowers, and the flowers are nice when they come later in the year. The plants are fast and tough and a good native habitat plant. I like them; we have one in our own garden. But they are not for every garden. The form is kind of rangy and thickety if you don’t prune it frequently, the bloom should be deadheaded, and the leaves can get tired and yellow by mid-summer with no fall color before they drop.

And ninebarks just can’t compete head to head with a Ribes; few things can. Ribes sanguineum is beautiful and native and fast and tough and a great habitat plant, and it will thrive in virtually any spot where you’d put a ninebark. It’s good for habitat and genetic diversity reasons to plant the ninebark (most Ribes in retail nurseries are from just a few cultivars), but most people, and most clients, will prefer the Ribes. We do plant ninebarks- like I said, we’ve got one in our own garden (along with two Ribes)–but we’ve probably installed six or eight Ribes for every one ninebark. I’m sympathetic to the native plant enthusiasts who want as much diversity and habitat value as possible in gardens, but sometimes it comes down to just looking at two plants side by side and picking. Fortunately, we don’t always have to pick between the two, and we do sometimes find gardens for ninebarks. Ninebarks are nice, they just aren’t awesome.

I put a few photos of the hedged ribes mound that the landscape architect was intending. I don’t really understand the urge to turn two perfectly nice Ribes shrubs into a single Ribes shrub mound. (more…)

Roots!

But it feels like most people plant them as if they were. We see tons and tons of sick, unhealthy plants, especially trees and shrubs, that have been planted by well-meaning, and sometimes even professional, gardeners who bury the root crowns of the plants. It’s reached the point that we automatically check if the crowns are buried whenever we look at someone’s garden. Nine out of ten times, if a tree is sick, the crown is buried. I’m not sure why people plant that way. I probably did it years ago, too, but I don’t remember the thinking behind it. I guess the plants seem more solid when their trunks have a lot of dirt holding them in place. Also, I think it might be because people’s first gardening experience is with a tomato.

Tomatoes are one of the few plants that actually benefits from having the root crown and stem buried. If you bury the root crown (the spot where the stem or trunk meets the soil and starts to put out roots) and the stem of a tomato plant, the branch nodes will form new roots and you’ll get a more vigorous plant. If you bury the root crown or stem of most other plants, the stem will slowly rot and the plant will die. It can take a long time, sometimes years, for a plant to die from a buried crown, so a well-intentioned gardener might never learn why their plants tend to mysteriously kick the bucket. It’s the most common cause of problems when we consult on sick plants, and I have a theory that it’s one of the most common causes of black thumbs. I know at least one black thumb gardener who was losing plants for that reason.

A few plants, like tomatoes, benefit from being planted a bit deep. I have a short list, which I hope to add to over time, of those plants below. Let me know of any I should add to the list. (more…)