Fall flowers need not be limited to the standard asters and mums. The autumn crocus (Colchicum autumnale) also makes its debut in early fall, though its foliage is just a memory by then. The dark green leaves that are roughly 10 inches long emerge in the spring before yellowing and dying by early summer as the plant goes dormant. Then, flower stems stretching around 6 to 10 inches high pop up from the ground in the fall with star-shaped blooms.
One of the plant’s common names—naked ladies—comes from the fact that no foliage accompanies its blooms. This plant has a moderate growth rate. The dormant bulb-like corms should be planted in the mid- to late summer for a fall bloom.
|Botanical Name||Colchicum autumnale|
|Common Names||Autumn crocus, meadow saffron, naked ladies|
|Mature Size||6–9 in. tall and wide|
|Sun Exposure||Full, partial|
|Soil Type||Loamy, well-drained|
|Soil pH||Acidic, neutral, alkaline|
|Flower Color||Pink, purple, white, yellow|
|Hardiness Zones||4–8 (USDA)|
|Native Area||Europe, Africa, Asia|
|Toxicity||Toxic to people and animals|
Autumn Crocus Care
Autumn crocuses are low-maintenance plants for the garden. They don’t typically have serious pest or disease issues, and rabbits and deer tend to leave them alone.
Plant the corms around 3 inches deep and 6 inches apart. Some gardeners choose to plant them in the middle of a border, where their foliage will be hidden by other plants and where the sometimes floppy flowers can lean on neighboring plants for support. A small amount of moisture during the summer is necessary to trigger root growth and get the bulbs going. However, make sure the corms are in a spot that has sharp soil drainage, or they might rot.
The autumn crocus needs at least a half-day of full sun during its foliage phase. Because this occurs in the spring, it’s OK to plant the autumn crocus under deciduous trees, as the trees won’t have leafed out yet. The flowers will grow fine with some shade.
Autumn crocuses can grow well in both a sandy loam or a rocky soil. The key factor is good soil drainage. Moreover, they can handle a slightly acidic to slightly alkaline soil pH.
A moderate level of soil moisture is ideal for the autumn crocus. Soil that is too soggy can rot the plant while soil that is too dry can desiccate the corm. Water roughly weekly during the growing season, reducing watering when the foliage dies back but increasing it again when the flowers appear.
Temperature and Humidity
There is a relatively narrow growing zone for the autumn crocus compared to some other flowering bulbs. Neither frigid winters nor warm winters provide the right conditions for dormancy for the corms. Whether your summers are hot or cool is less important. Excessive humidity can encourage botrytis, a fungal disease, but sunlight and good drainage can thwart this.
The autumn crocus grows fine without additional fertilizer. You can add some bone meal at planting time if your soil is poor.
Autumn Crocus Varieties
There are several varieties of the autumn crocus, including:
- ‘Innocence’: This plant features clear white blooms and likes partial shade.
- ‘Waterlily’: This variety sports double pink blooms.
- ‘Disraeli’: The checkered pink blooms on this variety make a fascinating addition to the fall garden.
As with all flowering bulbs, it's important not to cut back the foliage of the plant but to allow it to die back naturally. You can prune away the foliage after it has turned yellow.
Propagating Autumn Crocus
Your autumn crocus will naturally propagate by forming small corms on the main corm. You can take advantage of this by digging up the plant and removing the baby corms in the summer when the plant is dormant. Replant them 6 inches apart, and they will enlarge and reach blooming size in a couple of seasons.
How to Grow Autumn Crocus From Seed
Sow seeds outdoors in the fall, as they need a chill period to trigger germination. Cover them, so they are just buried in the soil. Germination is slow and can take a year in some cases.
Potting and Repotting Autumn Crocus
You can grow autumn crocuses in pots, but they might not return reliably the next growing season. Pot them in mid-summer using a standard potting mix, and water when the soil is dry. After blooming and the first hard freeze, place the pot in a shed or garage for winter. Repot every few years when the corms become crowded.