Light
Full sun suits it best. It tolerates some light shade, but Missouri Botanical Garden warns that too much shade, like too-rich soil, gives weak, floppy growth.
Water
Water new plants until they're established. After that it's drought and heat tolerant and rarely needs a drink in the ground. In pots, water when the mix has dried out. Wet, poorly drained soil is what rots it.
Soil & pots
Sandy or gravelly soil of average to moderate fertility is ideal, though Missouri Botanical Garden says this cultivar adapts to anything from pure sand to solid clay, as long as it drains well. The RHS suggests alkaline to neutral soil. Skip the fertilizer. Use it as a small-area ground cover, along edges, in rock and gravel gardens, and in containers.
Temperature
Hardy in USDA zones 3–9, and evergreen, so the blue-gray mat stays put through winter. The RHS rates it H5, hardy in most of the UK even in severe winters, and suggests a sheltered spot. Wet soil in winter is a bigger threat than cold.
Is Blue Spruce sedum safe for pets?
Pet safety not yet confirmed. It isn't on the ASPCA's toxic or non-toxic plant lists, and we haven't found a veterinary source. NC State Extension's profile of Angelina, a cultivar of the same species, notes the leaves can upset the stomach if eaten in quantity and the sap can irritate some people's skin. We haven't found a reliable source yet, so keep it out of reach of pets that chew plants.
Propagation
The RHS recommends softwood cuttings, taken from soft new growth in early summer. You can also split pieces off an established mat.
- Snip a few non-flowering shoot tips, a couple of inches long.
- Push them into gritty, well-drained mix, or straight into the ground where you want more cover.
- Keep the soil lightly moist until they root, then water sparingly.
- To divide, lift a section of the mat in spring, replant it in sun and water it in.
Common problems
FAQ
Is Blue Spruce sedum a Sedum or a Petrosedum?
Kew's Plants of the World Online accepts Petrosedum rupestre for this species and treats both Sedum rupestre and Sedum reflexum as older names for it. So Blue Spruce is Petrosedum rupestre 'Blue Spruce', even though the RHS and most nurseries still call it Sedum.
What's the difference between Blue Spruce and Angelina sedum?
Mostly color. They're cultivars of the same species, with the same needle-like leaves and the same needs. Blue Spruce is blue-gray. Angelina is yellow, and in cold-winter areas its leaves usually turn reddish-orange in fall. They look good planted together.
Does Blue Spruce sedum flower?
Yes, in early summer, which Missouri Botanical Garden puts at June and July. Upright stems carry clusters of star-shaped yellow flowers. The RHS notes the buds nod at first and turn upward as they open. Butterflies visit them.
Will Blue Spruce sedum grow in clay?
Missouri Botanical Garden says it adapts to soils from pure sand to solid clay. Drainage still matters, because it rots in soil that stays wet. In heavy clay, plant it on a slope or a raised spot where water runs off.
Is Blue Spruce sedum deer resistant?
Yes. Missouri Botanical Garden lists it as tolerant of deer and rabbits.
Sources
- Petrosedum rupestre (Plants of the World Online, Kew)
- Sedum rupestre L., a synonym of Petrosedum rupestre (Plants of the World Online, Kew)
- Sedum reflexum L., a synonym of Petrosedum rupestre (Plants of the World Online, Kew)
- Sedum 'Blue Spruce' (Plant Finder, Missouri Botanical Garden)
- Sedum rupestre 'Blue Spruce' (RHS)
- Sedum (NC State Extension Plant Toolbox)
- Petrosedum rupestre 'Angelina' (NC State Extension Plant Toolbox)
- Sedum rupestre 'Angelina' (Plant Finder, Missouri Botanical Garden)
- Toxic and Non-Toxic Plant List, Cats (ASPCA)
- Toxic and Non-Toxic Plant List, Dogs (ASPCA)