Petrosedum forsterianum (Rock Stonecrop)
Petrosedum forsterianum (Rock Stonecrop), formerly known as Sedum forsterianum, is a succulent plant with heads of yellow, star-shaped…
Making a Garden
garden writer, creator,
Greg Shepherd is an avid plant collector and nurseryman. Together with Paul Bonine, Greg is the co-owner of Xera Plants, a retail nursery and wholesale grower based in Portland, Oregon that specializes in climate-adapted plants for gardeners in the Pacific Northwest.
I’ve been gabbing with Greg for years. Back when I owned Fremont Gardens, a small specialty nursery in Seattle, Xera Plants was one of my prime suppliers. Orders delivered by Greg were always an occasion to chat about new plants and compare notes on the growing season. To this day, my garden still contains many signature Xera plants, and no visit to Portland is complete without a visit to this trusted purveyor of choice and often hard-to-find horticultural treasures.
I was delighted when I got the chance to visit Greg’s personal garden and catch up.
Arctostaphylos ‘John Dourley’, Yucca linearifolia, and Callistemon pityoides ‘Mt. Kosciuszko’ lend structure and form to the curbside plantings, while an interesting mix of resilient drought tolerant shrubs furnish the entry where overgrown rhododendrons once lurked. Photo: Greg Shepherd
Greg and his partner Christian Sledd live in NE Portland, an area of the city that’s prone to punishingly cold winter winds that spill into the neighborhood from the Columbia Gorge. They moved into their home in the fall of 2011 work began on the garden almost immediately.
This is the fourth garden that Greg has created. I was surprised—and comforted—to hear this expert plantsman confess, “It’s easy to get overwhelmed when planting a new garden, and even easier to end up with an over-planted mish mash of plant types and styles.”
In his previous garden, Greg limited himself to using plants from Oregon and California. “I found the restraints made the plantings more cohesive, and the challenge made the process fun as well,” he recounted.
Cool colors and fine textures in the back garden include Leptospermum lanigerum ‘Silver Form’ with blooms of Stipa barbata with contrast provided by the serate foliage of Melianthus major ‘Antonow’s Blue’. Photo: Greg Shepherd
This time around Greg upped the ante and decided to work within the following parameters:
- Only use plants grown by Xera.
- Stick to plants that had low or no summer water requirements.
- Plant directly into the native soil, no added amendments except in one area—more on that later.
- And finally, the plants would have to not just survive, but thrive in the face of the harsh winter winds.
“I wanted to create a trial plot for many of the plants we grow at Xera and that I feel are underused here in the Northwest,” he observed. “Limiting my choices challenged me to think outside of the box.”
Choosing only plants that would thrive without winter protection forced Greg to forgo planting many of his favorites that he’d grown in milder gardens, including annuals and tender tropicals, to say nothing of giving up dozens of potted plants that he used to shelter from inclement conditions. Focusing on plants that would flourish with minimum input was critical to Greg’s work/life balance. “As a busy entrepreneur I always ended up resenting the time I spent maintaining my previous gardens.”
Euphorbia rigida and Opuntia polyacantha Pink Hybrid. Photo: Greg Shepherd
The result is a beautiful garden that syncs with a busy life yet satisfies the curiosity of a passionate plant collector and grower.
The landscape, which sits on a typical 50- by 100-foot lot, is furnished with Western natives and adapted plants from similar climate regions with winter wet/summer dry weather cycles. The color palette is subtle and sophisticated bronze, gold, and soft sunset hues in the front yard, and lots of silver foliage and white, pink, and blue flowers in the back. Rather than creating sharp contrasts with bold foliage and bright colors, Greg composed a mix of fine textures, a decision informed by his time botanizing throughout the West. “I wanted to mimic a natural environment, where you often see many similar textures and forms melded into a cohesive wash of color and form,” he said.
Early in the process, Greg and Christian discovered that a large big-leaf maple anchoring the entry was mostly hollow and rotten. It would have to come down. What was going to be a shady front yard filled with Northwest natives was now going to be exposed to hot blazing sun. “Luckily we realized this before planting had begun,” Greg mused. Forced to adapt, their concept shifted to creating a chaparral-like landscape, densely planted with a mix of resilient drought tolerant plants.
But first they had to remove a dozen overgrown, poorly pruned rhododendrons that formed an impenetrable barrier across the front of the house and down the side yard. Once the “grueling” shrub removal was accomplished, beginning in October, they sheet mulched the existing lawn in anticipation of planting the following spring. As Greg noted, “Sheet mulching over winter is a slow process you’ll get much faster results if it’s done at the warm end of the wet season, in May or June.” They covered the lawn with cardboard and topped it off with a 3- to 4-inch layer of a 3-way mix. “I didn’t want compost because I knew I’d be growing a lot of natives and low-nutrient requirement plants and I didn’t use bark because I knew I would be double digging and changing the grade in some areas.”
A built up area on the south edge of the front garden amended with pumice creates optimal growing conditions for plants that require fast drainage, including Agave bracteosa and Opuntia polyacantha (both at top right), skirted with Euphorbia rigida and Sedum forsterianum (in bloom). Photo: Greg Shepherd
No soil amendments or fertilizers were added as they began digging and turning the soil—especially important in the compacted areas that had been covered in turf. The only exception was a bed destined to host Opuntia, Agave, and Yucca where Greg amended the native soil with fifty percent pumice to provide extra drainage around the crowns of the plants to help them establish in the wet winter climate.
Planting began in May of 2012, continued throughout the heat of the summer, and finished up in August. Knowing his goal was to test plants for drought tolerance, Greg decided against installing an irrigation system. “To establish new plantings, I hand watered every two to four days for the first few weeks, then tapered off to once or twice a week once the plants started to root in,” Greg recalled. “Now, 6 years later, I hand water specific plants about every two weeks in the summer. But most of the large shrub plantings haven’t been watered since their first season.”
Edible crops like a fig tree, dinosaur kale, and onions with Eryngium gianteum ‘Miss Wilmott’s Ghost’. Photo: Greg Shepherd
When asked to name his favorite plants and those that have proven exceptionally successful in his latest garden experiment, Greg tops the list with Arctostaphylos of any type. “My favorites are A. manzanita ‘St. Helena’ and ‘Austin Griffiths’.” Greg has trained beautifully sculptural specimens in the front yard into tree-like forms. “The plants have grown eight feet tall and as wide in just six years. They are completely unfazed by the hottest weather, and even rebounded intact after being bent to the ground by an ice storm,” he enthused. Other Arctostaphylos favorites include A. ‘John Dourley’, with a low, flowing form clothed in blue foliage that emerges copper-orange and blooms from December to March. And A. silvicola ‘Ghostly’, with amazing nearly white new growth and a soft, upright form.
I got the definite impression Greg’s list could go on and on.
Halimium ocymoides and Yucca linearifolia. Photo: Greg Shepherd
Beyond manzanitas, Greg had nothing but praise for the following choice plants:
- Ozothamnus ‘Silver Jubilee’ has silver foliage, a sagebrush-like form, and great drought and cold hardiness. “It grows quickly so it makes a great filler and is a perfect addition to young gardens.”
- Callistemon provides unique exotic texture that mixes well with other shrubs and showy spring bottlebrush flowers the long arching stems provide movement in the garden. “Callistemon pityoides ‘Excellent’ and C. viridiflorus ‘Xera Compact’ are a couple of my favorites.”
- Leptospermum, like bottlebrush, provides fine texture and lots of movement. “With copper-toned foliage and wiry growth, L. rupestre ‘Squiggly’ is a favorite that I’ve sprinkled around the garden.”
- Agave bracteosa is a non-spiny form of a notoriously prickly plant. “So easy to work into dense plantings and does quite well here over the winter—forms nice colonies too!”
- Yucca linearifolia “Stunning all year.”
Even with all his pro knowledge, Greg told me he’s had some failures. “Agastache. Love them, but they failed to establish in most areas—just too dry!” he lamented. “I’ve found that perennials are the most difficult plant type to integrate into a dry garden. As the garden matures, most perennials can’t compete for scarce summer water with the increasingly aggressive roots of large shrubs.”
Callistemon viridiflorus ‘Xera Compact’ contrasts with the finely textured lilac-gray foliage of Muehlenbeckia ephedroides.
Photo: Greg Shepherd
Instead, Greg has embraced self-sowing plants that move about the garden, often planting themselves in unexpected combinations, to provide shifting seasonal interest. Some of his favorites include Euphorbia rigida with cheery, early season flowers, sun loving Digitalis obscura with sunset orange flowers, and West Coast native annuals like the low growing white form of California poppy (Eschscholzia californica ‘Alba’), and meadowfoam (Limnanthes douglasii and L. alba).
Other perennial successes include Sedum sediforme ‘Spanish Selection’, with tall showy stems of the softest yellow flowers. Among grasses Greg extolled the powder blue foliage of Schizachyrium scoparium ‘The Blues’ that takes on purple highlights late in the season, and the “over-the-top” inflorescences and curly seed heads of Stipa barbata.
In shadier parts of the garden Greg’s go-to plants include Dicentra formosa ‘Langtrees’, a selection of native bleeding heart with silver foliage and white flowers. “It’s a great colonizer and will just go summer dormant if it gets too dry, but returns vigorously in spring.” Festuca rubra ‘Patrick’s Point’ is a West Coast native that slowly spreads to form large colonies of powder-blue foliage. “Makes wonderful soft drifts under shrubs and perennials.”
Pacific Coast hybrid irises (Iris ×pacifica) thrive under shrubs and in an open north exposure. “Flowering is brief, but makes mid spring so special.” The native licorice fern (Polypodium glyceryrrhiza) remains lush and green all winter, growing just as well in the ground as it does on vertical surfaces. “Without irrigation licorice fern goes summer dormant, perfect for under large shrubs like manzanita where you don’t want to water.”
Choice shade tolerant evergreen, woody plants that made the cut include Pittosporum illicioides—“Super tough and cold hardy with a lacy almost Japanese maple-like form”, and Pittosporum tobira ‘Tall and Tough’—“Supremely drought tolerant and nice looking all year.”
Only a couple of hebes, ‘Karo Golden Esk’ and ‘Hinerua’, have survived hot, dry summer conditions in the garden. Some failed from getting too dry, others perished after being watered in hot weather. As the knowledgeable nurseryman observed, “Many alpine and West Coast native plants just can’t tolerate moist soils and high temperatures.” Exceptionally cold winters have taken a toll as well. “I miss my restio (Ischyrolepis subverticillata). And my spineless prickly pear (Opuntia cacanapa ‘Ellisiana’) snapped into pieces and turned to mush after a heavy snow and ice storm a few years ago.” Prolonged periods when the subfreezing east wind whistles through the garden can also lead to bark split on some zone 8 plants.
Such is life in a plantsman’s garden where curiosity, observation, and knowledge cultivate success.
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A pointed planting of Melianthus major and Cynara baetica var. morrocana. Photo: Greg Shepherd
Plants→Petrosedum→Sedum (Petrosedum forsterianum 'Oracle')
|Plant Habit:||Herb/Forb |
|Water Preferences:||Mesic |
|Resistances:||Drought tolerant |
|Propagation: Seeds:||Self fertile |
|Thread Title||Last Reply||Replies|
|A place for pics of new plants. by purpleinopp||Oct 16, 2018 7:28 AM||148|
|Sedum and related succulents Chat 2016 by valleylynn||Oct 10, 2016 5:58 PM||424|
|Mystery sedum by valleylynn||Apr 19, 2016 1:54 AM||72|
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Today's site banner is by dirtdorphins and is called "muscari"
Sedum forsterianum 'Antique Grill'
Item #: 11383
Zones: 6a to 8b, at least
Height: 3" tall
Culture: Sun to Light Shade
Origin: Western Europe
Pot Size: 3.5" pot (24 fl. oz/0.7 L) ?
Note: This plant is not currently for sale. This is an archive page preserved for informational use.
Click Add to Wishlist to receive an email if this plant is back in stock.
(syn: Petrosedum forsterianum) This selection of the easy-to-grow Western European native stonecrop has been outstanding in our trials. a well-behaved delight in the rock garden, in rock walls, or on live roofs. Sedum forsterianum 'Antique Grill' forms a low 3" tall x 15" wide patch of fleshy, glaucous blue foliage that resembles a mass of blue eyelash brushes, emerging upright, before assuming a pronate position. The tiny yellow flowers adorn the foliage in summer, but it's the red pigment that begins to overtake the blue foliage when temperatures drop that makes a real show.
Stonecrop 'Oracle' (Sedum forsterianum)
Foliage forms a dense mound of handsome blue-green spiky leaves. Attracts butterflies to the garden. One of the least demanding, most satisfying perennials in the garden.
Classic plants for rock gardens! Looks great filling in between rocks and spilling over container edges. Perfect selection for filling in between paving stones.
Allow soil to dry between thorough waterings.
Basic Care Summary
Tolerates poor soil, heat, and drought. Does best in light, well-drained soil. Allow soil to dry between thorough waterings. Protect from excessive winter moisture.
Perennials can be planted anytime from spring through fall.
Prepare the garden by breaking up the existing soil (use a hoe, spade, or power tiller) to a depth of 12-16” (30-40cm). Add organic matter such as manure, peat moss or garden compost until the soil is loose and easy to work. Organic ingredients improve drainage, add nutrients, and encourage earthworms and other organisms that help keep soil healthy. Give plants an extra boost by adding a granulated starter fertilizer or all-purpose feed that encourages blooming (for example fertilizers labeled 5-10-5).
Check the plant label for suggested spacing and the mature height of the plant. Position plants so that taller plants are in the center or background of the landscape design and shorter plants in the foreground. To remove the plant from the container, gently brace the base of the plant, tip it sideways and tap the outside of the pot to loosen. Rotate the container and continue to tap, loosening the soil until the plant pulls smoothly from the pot.
Dig the hole up to two times larger than the root ball and deep enough that the plant will be at the same level in the ground as the soil level in the container. Grasping the plant at the top of the root ball, use your finger to lightly rake the roots apart. This is especially important if the roots are dense and have filled up the container. Set the plant in the hole.
Push the soil gently around the roots filling in empty space around the root ball. Firm the soil down around the plant by hand, tamping with the flat side of a small trowel, or even by pressing down on the soil by foot. The soil covering the planting hole should be even with the surrounding soil, or up to one inch higher than the top of the root ball. New plantings should be watered daily for a couple of weeks to get them well established.
Plan ahead, for plants that get tall and require staking or support cages. It’s best to install cages early in the spring, or at planting time, before the foliage gets bushy. Vining plants require vertical space to grow, so provide a trellis, fence, wall or other structure that allows the plant to grow freely and spread.
Finish up with a 2” (5cm) layer of mulch such as shredded bark or compost to make the garden look tidy, reduce weeds, and retain soil moisture.
New plantings should be watered daily for a couple of weeks. After that, depending on the weather and soil type, watering may be adjusted to every two or three days. Clay soils hold moisture longer than sandy soils, so expect to water more frequently in sandy settings.
Different plants have different water needs. Some plants prefer staying on the dry side, others, like to be consistently moist. Refer to the plant label to check a plant’s specific requirements.
Ideally water should only be applied to the root zone - an area roughly 6-12” (15-30cm) from the base of the plant, not the entire plant. A soaker hose is a great investment for keeping plants healthy and reducing water lost through evaporation. Hand watering using a watering wand with a sprinkler head attached is also a good way to control watering. If the garden area is large, and a sprinkler is necessary, try to water in the morning so that plant foliage has time to dry through the day. Moist foliage encourages disease and mold that can weaken or damage plants.
Thoroughly soaking the ground up to 8” (20 cm) every few days is better than watering a little bit daily. Deep watering encourages roots to grow further into the ground resulting in a sturdier plant with more drought tolerance.
To check for soil moisture, use your finger or a small trowel to dig in and examine the soil. If the first 2-4” (5-10cm) of soil is dry, it is time to water.
Incorporate fertilizer into the soil when preparing beds for new plants. Established plants should be fed in early spring, then again halfway through the growing season. Avoid applying fertilizer late in the growing season. This stimulates new growth that can be easily damaged by early frosts.
Fertilizers are available in many forms: granulated, slow-release, liquid feeds, organic or synthetic. Determine which application method is best for the situation and select a product with a nutritional balance designed to encourage blooming (such as 5-10-5).
Reduce the need to fertilize in general by applying a 1-2” (3-5cm) layer of mulch or compost annually. As mulch breaks down it supplies nutrients to the plants and improves the overall soil condition at the same time.
Depending on the flowering habit, snip off faded blooms individually, or wait until the blooming period is over and remove entire flower stalk down to the base of the plant. Removing old flower stems keeps the plant’s energy focused on vigorous growth instead of seed production. Foliage can be pruned freely through the season to remove damaged or discolored leaves, or to maintain plant size.
Do not prune plants after September 1st. Pruning stimulates tender new growth that will damage easily when the first frosts arrive. Perennial plants need time to prepare for winter, or “harden off”. Once plants have died to the ground they are easy to clean up by simply cutting back to about 4” (10cm) above the ground.
The flowering plumes and foliage of ornamental grasses create a beautiful feature in the winter landscape. Leave the entire plant for the winter and cut it back to the ground in early spring, just before new growth starts.
Perennials should be dug up and divided every 3-4 years. This stimulates healthy new growth, encourages future blooming, and provides new plants to expand the garden or share with gardening friends.