Use & Care NotesCompanion Plants
Holy Grail Hardy Hibiscus: Dinner-Plate Red on Near-Black Leaves
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Holy Grail hardy hibiscus is built for drama: oval, near-black leaves and saucer-shaped flowers 8 to 9 inches across in a rich, deep red. After the petals drop, bright green calyces stay behind for one more layer of contrast. It grows into a full, rounded bush about 4 to 4½ feet tall and 4½ to 5 feet wide.
It shares lavender's love of sun but not its thirst, or lack of one. That difference decides where it goes.
Holy Grail at a glance
| Trait | What to expect |
|---|---|
| Botanical name | Hibiscus 'Holy Grail' |
| Flowers | Deep red saucers 8 to 9 inches across |
| Foliage | Near-black, oval leaves |
| Size | 48 to 54 inches tall, 54 to 60 inches wide |
| Bloom | Mid-July into early September, peaking mid-August |
| Hardiness | USDA zones 4-9 |
| Light | Full sun for the darkest leaves; tolerates part sun |
| Wildlife | Great for pollinators and hummingbirds; moderately deer resistant |
How to pair it with lavender
The trick is to keep the hibiscus close enough to see together but far enough apart to water differently. A bed on the low side of a slope, a strip along a downspout or a regularly watered border at the edge of the lawn all work. Your lavender stays up on the dry ground; Holy Grail drinks below.
The timing is a bonus. Lavender peaks in early summer, and Holy Grail takes over as it fades, carrying color from late July into September. Deep red and near-black also make silver lavender foliage look brighter by contrast. Plan the spacing in the Companion Plant Planner; this plant needs about 5 feet of room.
Planting and care
- Site: full sun for the darkest leaf color, in poor to fertile soil that never dries out.
- Water: consistently. Flowers slow and leaves wilt if the soil dries in a hot spell.
- Pests: Japanese beetles, aphids and sawfly larvae are the usual visitors; check leaves in midsummer.
- Spring: it often does not appear until late May or June. Do not assume it is gone and dig it up.
- Cleanup: cut the woody stems back to a few inches in late fall or early spring.
Plug tray or bare root
Holy Grail is offered as a 72-cell plug tray for growers and anyone potting up stock, and as a bare root plant for a single focal point in a home garden. See each product page for current availability.
Frequently asked questions
Is it really hardy in Michigan?
Yes. It is fully hardy in zones 4-9 with no special winter care. The late spring start is normal.
Can I use the flowers in arrangements?
Not really. Each flower lasts a short time and they do not cut or dry well. Enjoy them on the plant.
Why are my leaves more green than black?
Shade dulls the color. The more sun it gets, the darker the foliage.
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