Saffron crocus
Crocus sativus · Iridaceae
Lilac-purple flowers in October, each with three long, red threads that are the spice saffron. The leaves grow through winter and die back in summer.
- Size
- 5 in tall, 3 in wide
- Zones
- 6 to 8
- Light
- Full sun
- Flowers
- Early October to early November
- Pets
- Toxic (mild)
- Job in a bed
- Bulb layer
A bed built around saffron crocus
The planner designed this bed around saffron crocus 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 saffron crocus stands where it does.
The plants
- 1 Moor grass 'Greenlee' × 8, tan
- 2 October daphne × 3, pink
- 3 Wild quinine × 5, white
- 4 Brown-eyed Susan × 3, yellow
- 5 Dwarf English boxwood × 1, dark green leaves
- 6 Eastern bee balm × 3, pink
- 7 Saffron crocus × 12, purple
- 8 Schubert's allium × 2, pink
Why this plant
- The only open bowls. The others are spires, dense clusters, flat plates and others. Shape reads at a distance, where colours blur.
- The only purple.
Why here
- In the middle. At 5 in it stands ahead of wild quinine (3½ ft) without hiding it.
- 12 plants in 2 handfuls. In the gaps between other plants, which fill the space when the bulb is not in growth.
Why now
- In flower for five weeks. From early October to early November.
- Closes the season. In its last week nothing else on the plan is in flower.
- Leaves gone by midsummer. They die back and leave bare ground. A perennial that comes up late stands beside it, and grows over the gap.
Planned as an English border: 5 of the 6 groups (83%) are drifts, longer along the bed than they are deep. The flowers run from early May to early November: 26 weeks in all. Low plants run along 96% of the front edge: moor grass 'Greenlee' and October daphne.
The planner's own design check: 13 Excellent, 4 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 saffron crocus goes in a border
At 5 in it belongs at the front of a bed. In the planner's ten height classes it is ground-hugging (up to 6 in).
Its job: bulb layer. Small bulbs planted in handfuls of five or seven in the gaps between other plants, for colour before the perennials wake up.
It needs a hot, dry, sunny place where the bulbs bake in summer. About fifty flowers give enough saffron for one meal, so plant generously.
- Growing your own saffron
- Autumn flowers in a herb or gravel garden
- Hot, dry spots
What to plant with saffron crocus
Plants recorded as good partners for it, and what each pairing does:
- Creeping thyme: flowers first, early June to mid July, so the spot is never empty; happy in the same dry soil.
- English lavender 'Hidcote': flowers first, late June to late July, so the spot is never empty; tall enough (18 in) to stand behind it; happy in the same dry soil.
- Sedum 'Angelina': its chartreuse leaves are a setting for the flowers, before and after; happy in the same dry soil.
Questions about saffron crocus
Does saffron crocus need sun or shade?
Saffron crocus grows in full sun (6 or more hours of direct sun a day).
It wants dry, sharply drained soil, of average fertility, and little watering once settled.
What zones does saffron crocus grow in?
USDA zones 6 to 8. It is hardy to zone 6, which means it survives winter nights down to about 0 °F (−18 °C).
Above zone 8 it struggles: the zones measure winter cold, but a plant's top zone usually means the summers are too hot or the winters too mild for it to rest.
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does saffron crocus flower in my zone?
In zone 5 it flowers early October to early November. As an autumn flower it keeps much the same dates in every zone: it answers to shortening days and cool nights more than to the warmth of spring.
| Zone 6 | Early October to early November |
|---|---|
| Zone 7 | Early October to early November |
| Zone 8 | Early October to early November |
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 saffron crocus be planted?
3 in (8 cm) apart, from the middle of one plant to the middle of the next. That is about its full width, so each plant keeps its own outline.
It grows 5 in (12 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many saffron crocus plants do I need?
At 3 in apart, set out in staggered rows:
- 168 to fill 10 square feet (about 1 m²)
- 39 for a single row 10 ft (3 m) long
- 536 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as handfuls of five or seven, in the gaps between other plants.
In the bed above, the planner used 12 in two groups.
Is saffron crocus poisonous to dogs and cats?
Yes: mild toxicity to dogs and cats. May cause mild stomach upset if eaten. This is a true crocus, not the highly poisonous meadow saffron (Colchicum).
Rated from NC State Extension. Where references disagree, the more cautious rating is used.
Do deer eat saffron crocus?
They may. NC State does not list it as resistant to deer or rabbits. Where they visit, protect it, or plant it among ones they avoid.
What can I plant to hide saffron crocus's leaves after it flowers?
A bulb's leaves have to be left to yellow for about six weeks after flowering, to feed next year's flowers. Plant it among perennials that come up late and spread wide, and they grow over the leaves as they fade:
- Lady's mantle: 18 in tall and 24 in wide, in flower late May to early July.
- Catmint 'Walker's Low': 24 in tall and 2½ ft wide, in flower mid May to mid September.
- Garden chrysanthemum: 24 in tall and 24 in wide, in flower mid September to late October.
What does saffron crocus look like in winter?
Saffron crocus is underground: it dies back after flowering and waits as a bulb until spring. Mark where it is, so a fork does not find it first.
More Crocus
- Autumn crocus Crocus speciosus
- Crocus Crocus vernus
- Crocus 'Ruby Giant' Crocus tommasinianus 'Ruby Giant'
- Early crocus Crocus tommasinianus
- Snow crocus Crocus chrysanthus
In these guides
Every fact on record
- Type
- Bulb
- Size
- 5 in (12 cm) tall, 3 in (8 cm) wide
- Plant
- 3 in (8 cm) apart
- Height class
- Ground-hugging (up to 6 in)
- Place in the bed
- Front
- Flowers
- Early October to early November; open bowls; purple
- Leaves
- Fine texture, summer-dormant; green
- Shape
- Upright, clumping
- Hardy in
- USDA zones 6 to 8
- Light
- Full sun
- Soil
- Average, dry and sharply drained
- Water
- Low
- Feeding
- None needed
- Family
- Iridaceae
Checked against NC State Extension. 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.