Sea holly 'Blue Hobbit'
Eryngium planum 'Blue Hobbit' · Apiaceae
A dwarf sea holly, a third the height of the species, that hides its leaves under a mass of small, steely blue thimbles.
- Size
- 12 in tall, 12 in wide
- Zones
- 4 to 9
- Light
- Full sun
- Flowers
- Late June to late August
- Pets
- No toxicity recorded
- Job in a bed
- Accent
A bed built around sea holly 'Blue Hobbit'
The planner designed this bed around sea holly 'Blue Hobbit' when this page was made: a 12 × 6 ft (3.7 × 1.8 m) English border in zone 6, full sun. It chose the other plants from the 715 that suit those conditions and its dry soil, and says below why sea holly 'Blue Hobbit' stands where it does.
The plants
- 1 Sea holly 'Blue Hobbit' × 2, blue
- 2 Winter heath × 7, pink
- 3 Cheddar pinks 'Firewitch' × 19, pink
- 4 Brown-eyed Susan × 3, yellow
- 5 Little bluestem × 3, blue-green leaves
- 6 Sea kale × 1, white
- 7 Ornamental onion 'Purple Sensation' × 4, purple
- 8 Lady tulip × 10, white
Why this plant
- The only blue.
Why here
- Near the front. At 12 in it is the step between winter heath (10 in) in front and brown-eyed Susan (4 ft) behind: each is seen over the one before.
- 2 plants in 2 places. An accent is a punctuation mark: the repeat along the bed gives it rhythm.
Why now
- In flower for 9 weeks. From late June to late August.
- Fills a gap. For three of those weeks nothing else on the plan is in flower.
Planned as an English border: 3 of the 5 groups (60%) are drifts, longer along the bed than they are deep. The flowers run from late January to early October: 37 weeks in all. Cheddar pinks 'Firewitch' repeats along the bed to tie it together.
The planner's own design check: 12 Excellent, 5 Good. It flags one thing to watch: Nothing on this plan is highly poisonous or an aggressive spreader.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where sea holly 'Blue Hobbit' goes in a border
At 12 in it belongs at the front of a bed. In the planner's ten height classes it is low (6 to 12 in).
Its job: accent. An upright plant used singly, like a punctuation mark, and repeated at intervals to give the bed rhythm.
It brings the thistle shape to the front of the border and to pots. Bees and small wasps crowd it. Like all sea hollies it wants sun and soil that is not too good.
- The front of a dry border
- Containers
- Bees
What to plant with sea holly 'Blue Hobbit'
Plants recorded as good partners for it, and what each pairing does:
- Sedum 'Angelina': its chartreuse leaves are a setting for the flowers, before and after; low enough (5 in) to stand in front of it; happy in the same dry soil.
- Blue fescue: its blue-green leaves are a setting for the flowers, before and after; happy in the same dry soil.
- Threadleaf coreopsis 'Moonbeam': blue against yellow, opposite each other on the colour wheel, in flower together for nine weeks; happy in the same dry soil.
Questions about sea holly 'Blue Hobbit'
Does sea holly 'Blue Hobbit' need sun or shade?
Sea holly 'Blue Hobbit' grows in full sun (6 or more hours of direct sun a day).
It wants dry, sharply drained soil, on the lean side, with no feeding, and little watering once settled. Once settled in, it stands drought.
What zones does sea holly 'Blue Hobbit' grow in?
USDA zones 4 to 9. It is hardy to zone 4, which means it survives winter nights down to about −20 °F (−29 °C).
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does sea holly 'Blue Hobbit' flower in my zone?
In zone 5 it flowers late June to late August. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 4 | Early July to late August |
|---|---|
| Zone 5 | Late June to late August |
| Zone 6 | Late June to late August |
| Zone 7 | Late June to mid August |
| Zone 8 | Late June to mid August |
| Zone 9 | Mid June to early August |
Worked out from Hopkins' bioclimatic law: spring arrives about four days later for each degree of latitude north, and one zone is roughly two degrees. A warm spring or a cold one moves any garden two weeks either way.
How far apart should sea holly 'Blue Hobbit' be planted?
10 in (25 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 12 in (30 cm), so a group knits into one patch.
It grows 12 in (30 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many sea holly 'Blue Hobbit' plants do I need?
At 10 in apart, set out in staggered rows:
- 17 to fill 10 square feet (about 1 m²)
- 13 for a single row 10 ft (3 m) long
- 55 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as one at a time, repeated along the bed at intervals; a slender one reads better as a clump of three.
In the bed above, the planner used two in two groups.
Is sea holly 'Blue Hobbit' poisonous to dogs and cats?
No toxicity is recorded for dogs, cats, horses or people, according to NC State Extension.
"Not toxic" is not "edible": a pet that eats a lot of any plant can be sick.
Is there a native plant like sea holly 'Blue Hobbit'?
Sea holly 'Blue Hobbit' comes from E. Central Europe to Mongolia and W. Himalaya. These North American natives come closest to doing its job:
- Blanket flower 'Arizona Sun': the same size; a drift, not an accent, flowers mid June to early October.
- Harebell: the same size, the same flowering time and the same colour; a weaver, not an accent, fine leaves, not medium.
Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.
Do deer eat sea holly 'Blue Hobbit'?
Mostly not. NC State lists it as resistant to deer and rabbits. No plant is proof against a hungry deer in a hard winter, but this one is low on the menu.
What flowers after sea holly 'Blue Hobbit'?
Sea holly 'Blue Hobbit' is over by late August. These start as it finishes and carry the same spot on, so it never goes flat:
- Garden chrysanthemum: from mid September to late October, 24 in tall.
- Sedum 'Autumn Joy': from mid August to mid October, 24 in tall.
- Meadow saffron: from mid September to mid October, 6 in tall, to stand in front of it and cover its fading stems.
What does sea holly 'Blue Hobbit' look like in winter?
Sea holly 'Blue Hobbit' dies down to the ground and there is nothing to see until spring. The old stems can be cut in autumn, or left until spring as shelter for overwintering insects.
Is sea holly 'Blue Hobbit' good for bees and butterflies?
Sea holly 'Blue Hobbit' is visited by pollinators, bees and butterflies.
More Eryngium
- Alpine sea holly Eryngium alpinum
- Mediterranean sea holly Eryngium bourgatii
- Miss Willmott's ghost Eryngium giganteum
- Rattlesnake master Eryngium yuccifolium
- Sea holly Eryngium planum
- Sea holly 'Big Blue' Eryngium x zabelii 'Big Blue'
In these guides
- Salt-tolerant plants for roadsides and coasts
- Deer-resistant perennials for full sun
- Rabbit-resistant plants
- Drought-tolerant perennials for full sun
- Pet-safe plants for a sunny border
- Plants for butterflies
- Plants for bees
- Low plants for the front of a border
- Plants with blue flowers
Zone guides: Zone 4 · Zone 5 · Zone 6 · Zone 7 · Zone 8 · Zone 9
Every fact on record
- Type
- Perennial
- Size
- 12 in (30 cm) tall, 12 in (30 cm) wide
- Plant
- 10 in (25 cm) apart
- Height class
- Low (6 to 12 in)
- Place in the bed
- Front
- Flowers
- Late June to late August; globes; blue
- Leaves
- Medium texture, herbaceous; green
- Shape
- Mounding, clumping
- Hardy in
- USDA zones 4 to 9
- Light
- Full sun
- Soil
- Lean, dry and sharply drained
- Water
- Low
- Feeding
- None needed
- Family
- Apiaceae
- Comes from
- E. Central Europe to Mongolia and W. Himalaya
- Attracts
- Pollinators, bees, butterflies
- Stands up to
- Deer, rabbits, drought, salt, poor soil
Checked against NC State Extension and VASCAN (plants of Canada). Flowering times are for zone 5: later in colder zones, earlier in warmer ones. Toxicity and spread information is a general gardening guide, not veterinary or medical advice, and invasive status varies by region. If a person or pet eats a plant, contact poison control or a vet. Check your local invasive species list before planting anything with a spread warning.