These Are the Most Popular Spring and Fall Crocus Varieties—Here's How to Plant, Grow, and Care for Each
An emerging crocus is one of the first signs that a new season is right around the corner; this plant type has spring- and fall-blooming species, which means you can enjoy it for the majority of the year. Best of all, these petite flowers make a lovely addition to any landscape—they give us a thrill whenever they begin to show their colorful heads. Ahead, how to identify, plant, and care for both the spring and fall crocus varieties you have growing in your garden.
The Key Differences Between Spring and Fall Crocuses
Before we get into the most common spring- and fall-blooming crocus varieties, it's important to mark these perennials' differences—beyond, of course, their seasonality. According to Anne Verdoes, a Netherlands-based bulb and garden expert with FlowerBulbs.com, the former are daintier and have "smaller, slender, grass-like foliage," while the latter boast larger "almost tulip-like leaves," but produce just one flower per stem; fall crocuses are also more resistant to winter's whims (certain varieties are hardy to zone five, notes Verdoes). Spring crocuses bloomers typically thrive in zones three and higher. One of the key differences between the two, however, comes down to toxicity: Autumn-blooming crocus varieties are poisonous due to their corms, which produce a compound called colchicine. "Because of its toxic nature, autumn crocus should not be planted in gardens frequented by unattended children or pets," notes Verdoes.
Planting Times for Spring and Fall Crocuses
Since their blooming seasons are different, so are their planting schedules. "Spring-blooming crocus are planted in fall, as long as you can still work the ground," notes Verdoes. "If you live in a climate without frosts, simply keep bulbs in the refrigerator until late winter and then plant them as annuals." As for their counterparts? Autumn crocus types, says Verdoes, "should be planted in late summer to establish by fall for blooming."
Care Requirements for Spring and Fall Crocuses
There are over 50 different types of spring-blooming crocus bulbs in colors ranging from white or pale pink and lavender to more intense shades of showy blue-violet, purple, orange, pink, or ruby, explains Verdoes, noting that all of these warm-weather varieties should be planted in full sun or partial shade. "The bulbs bloom and die back before most trees and shrubs have leafed out, which means they can be planted in areas that may be shaded in summer," she adds. "Space them three inches apart and plant them three inches deep." Fall-blooming iterations have waxy, large, irregular corms and dark-brown, leathery skin; they should be plant four to six inches deep in soil that has been amended with a general-purpose fertilizer (Verdoes recommends a 5-10-5 mix). "The best site is under deciduous trees or shrubs or mixed in with other perennials," she continues, "but avoid planting them in locations where the flowers will be hidden by falling leaves in autumn. Note that they do best when provided full sun in spring." If you need to move or divide these fall bloomers, do so in summer, after the leaves have died back but before the flowers begin to appear, Verdoes explains.
As for water and soil requirements? Spring crocus should be watered in the spring and fall; they prefer drier soil when they go dormant come summer. Types that bloom in autumn should be watered post-planting in late summer and while stems grow and flowers bloom. Both spring and fall crocus benefit from rich, well-drained soil ("Poor drainage can lead to rotting bulbs," notes Verdoes), but she notes that both unfussy types will tolerate sandy or clay soils, too. "Rock and herb gardens make ideal planting sites, as do raised beds and perennial borders," she explains (containers work, as well). "They look best when planted in clusters, large drifts, or scattered in five or more bulbs." Hoping to add a few spring and fall crocuses to your garden? Keep reading to discover some noteworthy varieties, courtesy of Verdoes.
Spring: Dutch Crocus (C. vernus)
This species is the toughest crocus of all, says Verdoes, and is available nearly everywhere. It comes in a rainbow of colors and is often marked with contrasting streaks or blotches.
Spring: Scottish Crocus (C. bifloris)
This showy white flower boasts subtle purple striped petals and yellow throats. Read the label and species name carefully, notes Verdoes: Some forms of Scottish crocus actually bloom in autumn.
Spring: Early Crocus (C. tommasinianus)
Looking to add an early pop of color to your spring garden? Work in this option, which is colloquially known as "Tommy." The small variety displays star-shaped blooms that are a cross between silver, blue and lavender. An added bonus? "These are the most squirrel-resistant because they contain alkaloids that the other crocus plants do not," notes Verdoes.
Spring: Golden Crocus (C. chrysanthus)
This sweet-scented variety is delightful, thanks to its orange-yellow blooms. Hybrids are available in many colors, including pure white, pale blue, pale yellow, white with purple edges, or blue with yellow centers, says Verdoes.
Fall: Autumn crocus (Colchicum autumnale)
Despite their common name (and wide availability), these aren't crocus flowers at all. In fact, they aren't even in the same family: "Colchicum belongs to the Colchicaceae family (formerly part of the lily family, Liliaceae), while crocus is in the iris family (Iridaceae)," explains Verdoes. Hardy to zone five, this sterile hybrid has lilac-pink flowers with multiple petals (often 20!) that resemble a waterlily.
Fall: Autumn crocus (Crocus speciosus)
This type will produce leaves in the spring; they die back as temperatures heat up. Also known as Bieberstein's crocus, the species bears attractive, light purple flowers with violet veins. In fall, the plants will send up six to seven-inch flower stalks with typical goblet-shaped crocus flowers that range from violet-blue to mauve. "It increases rapidly in the landscape and is a good choice for naturalization," Verdoes affirms.
Fall: Saffron crocus (Crocus sativus)
While not the most widely grown fall-blooming crocus, this iteration is arguably the most well-known: It's the plant the spice saffron comes from. They grow four to six inches tall and have lilac-purple flowers that open a few weeks after C. speciosus. "Each flower produces three reddish-orange stigmas which are harvested and dried to create saffron," shares the garden expert. "It takes about 250,000 stigmas from 75,000 flowers to produce one pound of saffron, all of which is handpicked. Now you know why saffron is so expensive!"