Colchicum

( KOL - chik - um )

At-A-Glance Information

Commonly called Meadow Saffron, Naked Lady or Autumn Crocus, these interesting flowering perennials grow from bulb-like corms. They enjoy full sun or bright indirect light and need regular waterings during their growth and blooming periods to perform well in the garden. Although they are commonly called Autumn Crocus, they are not true Crocuses. Plants send up large clusters of lavender, pink, rose or white flowers in late summer or early fall. Leaves will emerge in springtime, and then die long before the flowers sprout from the ground. Grow Autumn Crocus in front of shrubs, amongst low-growing perennial plants, around patios and walkways, or in woodland or meadow style landscapes. Take care when planting these in your yard, as all parts are poisonous to humans and pets if ingested.

Colchicum species and varietals

The genus Colchicum is the type genus member of the plant family Colchicaceae and includes about 160 species. Although many species in the genus are commonly called 'Saffron', the true Saffron spice is derived from a species in the genus Crocus. Autumn Crocus grows well in USDA hardiness zones 4-9 or Sunset growing zones 2-10, 14-24 or indoors. To find your zone, click here: Zone Map.

Colchicum x aggrippinum (Autumn Crocus, Naked Lady, Meadow Saffron)
This garden hybrid between Colchicum variegatum and Colchicum atumnale is considered one of the easiest plants in the genus to grow. Flower petals have a checkerboard pattern of pink and white, and they bloom in late summer or fall, followed by green strappy foliage. Individual plants reach up to 6 inches tall when in bloom.

Colchicum alpinum (Alpine Autumn Crocus, Alpine Saffron)
This species produces delicate, purple flowers and is native to the Alps and Appinninis of Italy, Switzerland, France, and Sicily. It is cultivated as a garden ornamental in many areas of the world. Flowers are light pink to white, and petals are faintly lined. Individual plants reach up to 8 inches tall when mature and in bloom.

Colchicum autumnale (Autumn Crocus, Meadow Saffron, Naked Boys, Naked Ladies)
This species is native to Great Britain and Ireland, and is cultivated in temperate areas as a garden ornamentals. Flowers are pink to purple, though there are also some cultivars that produce white blooms. Individual plants reach up to between 6 and 12 inches tall when in bloom. Foliage appears in springtime, and flowers bloom in fall. This species is considered invasive in certain regions of the United States and Canada. Varieties are listed below:

'Autumn Queen'
With violet blooms.

'Disraeli'
Checkered pink flowers.

'Giant'
With large white and mauve-pink blossoms.

'Innocence'
With clear white blooms; this variety prefers part shade.

'Waterlily'
With double pink blooms.

Colchicum balansae (White Autumn Crocus)
These plants produce white to pinkish flowers in fall and are native to Greece and southern Turkey. Individual plants can reach up to 4 inches tall and 6 inches wide at maturity. Flowers are typically produced very close to the ground.

Colchicum bulbocodium (Bulbocodium vernum) (Spring Meadow Saffron)
This alpine species is native to mountain ranges across Europe and is cultivated as an ornamental in many areas of the world. These plants are wonderful grown en masse in rock gardens, and reach between 3 and 4 inches tall when in bloom, and flower from April through June.

Colchicum x byzantinum (Byzantine Meadow Saffron, Autumn Crocus, Meadow Saffron, Naked Lady)
This hybrid is of unknown origin, and produces pink flowers in fall that have petals with a prominent central white stripe. These plants are very reliably grown as ornamentals in gardens. Individual plants reach 6-8 inches tall when mature and in bloom.

Colchicum cilicicum (Tenore Autumn Crocus, Cilician Meadow Saffron)
This perennial plant produces deep rose-lilac flowers in late summer that have white striping on the petals and is a popularly cultivated garden ornamental species. Variety 'Purpureum' is a choice cultivar for gardens. Cilician Meadow Saffron is native to Turkey and Syria.

Colchicum cupanii (Mediterranean Meadow Saffron, Busieq)
This species is native to the Mediterranean region and produce white to pink-purple flowers in fall, alongside foliage. Some blooms open fully, creating a star-pattern, others remain somewhat closed, taking the shape of a cup. These plants can reach up to 4-6 inches at maturity.

Colchicum luteum (Yellow Colchicum, Suranjan)
This native of central Asia, Afghanistan, Tibet, and Pakistan is the only species in the genus that produces yellow flowers. Individual plants reach up to 4-6 inches tall at maturity. A number of cultivars are available for purchase as garden ornamentals, including 'Golden Baby' and 'Vahsh'.

Colchicum macrophyllum (Large-Leaved Autumn Crocus)
This species produces large flowers that have a pink and lavender checkerboard pattern on the petals. Leaves are green and produced in spring; they reach up to 16 inches long when fully grown. These flowers are native to Turkey, Greece, and Crete.

Colchicum speciosum (Giant Meadow Saffron, Showy Autumn Crocus)
This species of Natal Lily produces 12 inch tall reddish purple flowers in fall, after leaves have faded for the year back in summer. These are vigorous growers, native to northern Turkey, the northern Caucasus, and northern Iran. Varieties include 'Album' (with white flowers), 'Atrorubens' (with amethyst-purple blooms).

Colchicum stevenii (Steven's Meadow Saffron, First-Rain Colchicum)
In this species, leaves and flowers are present simultaneously. Flowers are pink and bloom from October through December, usually appearing after the first big rain of the year.

Caring for Colchicum

Grow Colchicum flowers in a space in the garden that receives full sun to partial shade. The warmer the summer temperatures are in your region, the more shade these plants will require. Late afternoon shade can go a long way in preventing sunburn. They prefer soil that is both rich and well-draining, with a pH of between 4.5 and 7.5. If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. These plants do best in undisturbed areas of the garden, and should be planted around 3 inches deep and 6-8 inches apart. Planting in clumps provides the best landscaping effect. After planting Colchicum, mulch around the base of the plants with organic mulching material to help retain soil moisture and suppress weed growth. Keep mulch away from the plant stems, as this can encourage an environment for root rot issues to take hold. Water new plantings regularly as they establish a strong root system, but ensure that they are never sitting in standing water. At maturity, they prefer to have soil kept relatively moist during their growing and blooming seasons. During dormancy, they should be watered less but not allowed to sit in dry soil.

Water new plants regularly as they establish a strong root system. At maturity, these plants are relatively drought-tolerant, able to pull moisture and nutrients from their corms to carry them through dry seasons. For the best blooms, however, make sure these plants are getting irrigated at least once a week, or simply irrigate when the top inch or two of soil feels dry to the touch. Fertilize the planting area yearly with an application of about two inches of compost. Pull back mulch, apply compost, work the compost into the soil, and then water it in. Replace mulch afterwards and add more if necessary. This feeding is enough to carry these plants through their growing and flowering seasons, and they will not need any additional fertilizers. After flowers die back, leaves will appear. Spent blooms can be cut off at their base to neaten the appearance of plants. When foliage dies back in spring, it can be cut back as well. If growing Colchicum in containers, they will need to be divided every 3-4 years for best health and performance. They do not like to have their roots disturbed much, so make sure to carry out the process gently. For more information on dividing Colchicum corms, see the Propagation section below. In cool-weather areas, dig corms up each year after foliage has faded. Do not dig up after flowers fade, as the corms need to have a growth period afterwards to photosynthesize and send more energy into their corms. Dug up corms can be stored in a cool, dark, dry place in a bag of sawdust and replanted in springtime after soils warm up again. Colchicum plants are considered long-lived ornamentals, with many species living for 5-10 years or more in the garden before needing to be replaced.

Growing Colchicum Indoors
Colchicum are beautiful specimens when brought indoors. In a bowl, plant corms in 1-2 inches of pebbles and fill with water to the corm base. Place the plant in a spot in the home that receives bright, indirect light and is not drafty. Colchicum grown in containers does not always come back year after year like those grown in the garden, but they can still provide great seasonal interest to interior spaces.

Propagation

Colchicum, or Autumn Crocus, can be propagated either by division or from seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the division method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that the resulting plant may not necessarily be the same as the parent plant the seeds are harvested from. To propagate your Autumn Crocus, follow the instructions below:

Propagating Colchicum by Seed

Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. The best potting medium for seed germination is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
Harvest your seeds. The seed pods ripen in late spring to summer, and can be simply cut off of the plant and placed into a paper bag for temporary storage. Store the seeds over the winter in cool (but not frosty), dark conditions.
Colchicum seeds need a period of cold stratification to germinate. Place harvested seeds in a damp mixture of sand or peat moss in a sealable container or plastic bag, and place the container in the refrigerator for at least two to three months' time. Remove the seeds from their bed after the cold stratification period, and then soak them in lukewarm water for between 12 and 24 hours. Viable seeds will sink, and any that float can be discarded, as they will not germinate.
In early spring of the next year, water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination is usually pretty quick for these plants, occurring within 10-14 days after sowing.
Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until seedlings reach a few inches tall. Young seedlings are best stored in a shaded area of a greenhouse; direct sun can scorch the developing leaves.

Propagating Colchicum by Division
This type of propagation is relatively simple; you will need a clean shovel, mulch, fresh soil (any kind will do, though it does need to be well-draining), compost, and pots (only necessary if you will be saving divided plants for transporting elsewhere). Division is best done in spring or fall (after the plant has entered dormancy and been cut to the ground, but before it has begun its new spring growth), and needs to be done every few years regardless of whether you have the goal of propagating the plants for best performance. To propagate by division, follow these steps:

Gather your materials. Using a shovel, dig up your existing plant. Start from the outside and work your way in to avoid damaging the corm(s). Once you have worked them up out of the ground, gently lay them out.
Start to tease apart the roots with your gloved fingers. Once the roots are untangled, separate your corms into segments, ensuring that each one has at least one thick corm section to grow from. Smaller divisions can also be taken from the parent plant, though they may take a while before they are large enough to start blooming.
Prepare your pot(s) or new planting site(s) with amended, well-draining soil. You can either bring in new soil or simply amend your existing soil with compost to complete this task. Then, plant your divisions and water them in thoroughly.
Apply a thick layer of mulch over the new planting to protect it from cold weather as it acclimates to its new home. Then, enjoy watching it sprout.

Colchicum seeds are held in the spent flower heads.

Colchicum seeds are round to oval in shape, with a hard but thin brown seed coat.

Problems and Pests

Some species of Colchicum are considered invasive in certain regions; see the species descriptions above for more information. Check with local authorities before planting. On the bright side, due to the toxicity of these plants, they are unpalatable to many bulb-feeders such as deer, voles, mice, and other rodents. They can, however, suffer from time to time from the following pests and diseases in the landscape:

Snails and Slugs
Root Rot
Aphids
Leaf Spot

For more information on these pests and diseases, including how to treat and prevent them, consult the pages linked below:

Pests & Pest Management

Plant Issues

Gallery

Colchicum corms can be grown either in the ground or in pots indoors or outside.

Leaves and flowers appear at separate times of the year.

The strappy green foliage of Colchicum plants is pleasing in the landscape.

After foliage fades, it can be cut back.

The foliage of Colchicum compliments the plants around it in this garden bed.

This pathway is lined with evergreen foliage and pops of color thanks to Colchicum flowers.

This low bed features various groundcover-type plants as well as Autumn Crocus flowers.

Autumn Crocus is used to line the base of this rock planter. This is a great situation for these flowers, as they will not get overwatered at the edge of this lawn space.