Photo: George Chernilevsky, Public domain · source
Bulb or tuber · Iridaceae
Yellow crocus
Crocus flavus
In other languages: Gele krokus (Nederlands) · Crocus jaune (Français)
The yellow crocus, Crocus flavus, comes from south-eastern Europe and western Turkey and is the wild ancestor of the large yellow garden crocuses. It has been grown in gardens since the 16th century. In February and March each corm opens a few bright, golden-yellow flowers with a light honey scent. It is strong, multiplies quickly and naturalises easily in grass, where after a few years it forms golden carpets. For bees and bumblebees it is one of the first rich sources of pollen.
Caution: Crocus corms contain substances that cause stomach and bowel upsets if swallowed. Do not confuse them with the highly poisonous autumn crocus (Colchicum). Keep the corms away from children and pets.
Light
Sun or partial shade
preferably some sun
Moisture
Normal
no wet feet
Legal basis
Sand, loam or clay
neutral to chalky
Hardiness
Fully hardy
down to -25 °C
Size
0.1 m
tall, 0.05 m wide
Flowering
February–March
| Height | 0.1 m |
|---|---|
| Native to Belgium | No, planted |
| Good for bees, butterflies and birds | Yes, for bees |
| Poisonous to people and pets | Yes, take care with children and pets |
| Flowering | February–March |
Identify
Yellow crocus: how do you recognise it?
- Habit
- Small corm 8–10 cm tall.
- Leaf
- Narrow, grass-like, with a white central stripe, appearing with or just after the flowers.
- Flower
- Cup-shaped, golden to orange-yellow flowers 3–4 cm across, lightly scented.
- Flowering
- February and March.
- Corm
- Round corm with a smooth, papery tunic; quickly forms cormlets.
Flowering: February–March · Plants: September–November
In your garden
Why grow it?
- Bright golden-yellow flowers in February–March, a true herald of spring.
- A rich source of pollen for the first bees and bumblebees.
- Strong and easy: multiplies quickly and naturalises in grass.
- A light honey scent on sunny days.
- A classic that has been grown in gardens for centuries.
Yellow crocus: where does it grow best?
- Sun to light shade; the flowers open in sunshine.
- Any well-drained soil: sand, loam or light clay, chalky is fine.
- Normally moist; not too wet in summer.
- In grass, under deciduous trees, at the front of a border or in pots.
- Plant 50–100 corms per m² for a golden carpet.
- Light
- Sun and partial shade
- Soil type
- Sand, loam or clay
- Acidity
- Neutral or chalky
- Moisture
- Normal
- Size
- 0.1 m tall, 0.05 m wide
- Hardiness
- Hardy (to -25 °C)
Goes well with
- Blue crocus: Lilac and purple crocuses next to the golden yellow.
- Snowdrop: White in the same early weeks.
- Squill: Bright blue squills just afterwards.
- Daffodil: Early daffodils carry on the yellow display.
- Hellebore: Flowers at the same time in the border.
Maintenance
Yellow crocus: when and how to plant it?
Plant in September–November.
- Plant the corms in September–November.
- Set them 5–8 cm deep, 5 cm apart.
- In grass, scatter them loosely and plant them where they fall, for a natural effect.
- In heavy soil, add some grit under the corms.
- Plant in large groups: that is where they stand out most.
Care
- Water
- Not needed in the ground.
- Feeding
- Not needed; a little compost in autumn is fine.
- Leaves
- Let the leaves die back after flowering: this makes the corm stronger.
- Mowing
- In grass: mow only from late April or May, when the leaves are yellow.
- Mice
- Mice eat crocus corms; protect them with wire mesh if needed.
Tip: Mix yellow crocuses with lilac and purple kinds in the lawn: after a few years you will have a colourful carpet in March that wakes up the bees.
Yellow crocus: when to prune it?
When: No pruning is needed.
How:
- Just leave the faded flowers.
- The leaves die back on their own in April–May.
Caution: Do not mow the lawn until the crocus leaves have turned yellow.
Propagation
- Cormlets
- It quickly forms new cormlets; lift crowded clumps in summer and divide them.
- Sowing
- It self-sows in grass.
Yellow crocus: how does it get through the winter?
Hardy to −25 °C.
- Very hardy, to −25 °C.
- No protection needed.
- Flowers reliably even after a severe winter.
- In a cold snap during flowering the flowers close and reopen afterwards.
Diseases and pests
- Pecked flowers: Sparrows like to peck at yellow crocuses. Plant them in large groups so that enough survive.
- Missing corms: Mice or squirrels. Plant under mesh or in a basket.
- Few flowers: Too much shade or leaves mown too early.
Through the year
- February: Start of flowering. Bees and bumblebees.
- March: Full flower.
- April: Leaves die back.
- May: Mow grass once the leaves are yellow.
- September: Plant corms.
- October: Plant corms.
- November: Last corms.
Use
Edible and useful
Not edible. Crocuses are mildly poisonous: eating a corm or leaves can cause stomach upsets, with vomiting and diarrhoea, and dogs and cats fall ill from them too. Dogs sometimes dig up newly planted corms: plant them where your dog does not dig, and keep loose corms in a labelled bag out of reach of children and pets. The yellow or orange stigmas in the flower are not saffron: that comes only from the saffron crocus (Crocus sativus), which flowers in autumn. Do not confuse crocuses with Colchicum either, which is sometimes called autumn crocus or meadow saffron but is not a crocus and is highly poisonous: a crocus has three stamens, Colchicum six. If you also buy or store Colchicum corms, keep them separate and labelled. If any is swallowed, call a poison centre (in Belgium 070 245 245) or your doctor at once.
Good for wildlife
- Bees
- Nectar and pollen for honeybees and wild bees.
You and this species
Did you know?
- The large yellow garden crocuses, such as the well-known ‘Yellow Mammoth’ or ‘Golden Yellow’, were bred from this species.
- Sparrows mainly peck at yellow crocuses, probably looking for nectar or attracted by the colour.