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Growing and Caring for Spring Crocus Flowers: Planting and Maintenance Tips

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by

Ben

These late-winter blooms come back every year

The Spruce / Evgeniya Vlasova

Emerging from bulb-like structures called corms, crocuses are low-growing perennial flowering plants from the iris (Iridaceae) family that come back year after year for at least five years growing from one corm. In ɱaпy regions, crocus flowers (Crocus spp.) mark the arrival of spring. These early bloomers can often be seen peeking up through the snow well before any other flowers appear in your landscape in January, February, or March, depending on the severity of your winter.

Crocuses grow in various conditions, including woodlands, coastal gardens, and suburban lawns. Deer usually pass over them, but rodents like squirrels, chipmunks, and mice consider crocuses a tasty snack. Bloom colors on the cup-shaped flowers include mauve, lavender, and yellow. There are over 80 crocus species, but most commercially available corms are hybrid plants derived from carefully cross-breeding selected species.

While crocuses are often called bulbs, they are technically corms (like gladiolas). The main difference between corms and bulbs is that corms are rooting structures formed from modified stem tissue, while bulbs are formed from modified leaf tissue. Once established in an area, crocuses can spread independently by developing corm offsets.

Crocuses are most often planted for early spring color, though there are also varieties that bloom in late fall and early winter. Spring crocus is not the same as saffron crocus, a fall variety that produces saffron, a common spice and colorant used in cooking. Spring crocus is an especially early-blooming variety that should be planted in the early fall. The month it blooms varies; they typically bloom within two to five weeks after the temperature rises, growing fast and beginning active growth in the spring. Spring crocuses are toxic to pets.

What Does Spring Crocus Symbolize?

Spring crocuses are known for their unique symbolic meaning, as these special plants bloom during cold weather. Their flower represents rebirth, joy, hope, and fresh beginnings.

Common Name
Crocus

Botanical Name
Crocus spp.

Family
Iridaceae

Plant Type
Corm, Perennial

Mature Size
6 in. tall, 1-3 in. wide

Sun Exposure
Full, Partial

Soil Type
Well-drained

Soil pH
Neutral

Bloom ᴛι̇ɱe
Spring

Flower Color
Purple, blue, yellow, orange, pink, white

Hardiness Zones
3-8 (USDA)

Native Area
Europe, North Africa, Asia

Toxicity
Toxic to pets

The Spruce / Evgeniya Vlasova

The Spruce / Evgeniya Vlasova

The Spruce / Evgeniya Vlasova

Ekspansio / Getty Images

Planting

When to Plant

Crocuses are often one of the first late winter or early spring bloomers. They should be planted in the early fall. Crocuses usually emerge two to five weeks after the temperature rises in late winter or early spring, mainly dependent on the temperature shift.

Where to Plant

Crocuses prefer full sun spots, but since they bloom before trees have leafed out, they can be located under or near deciduous trees. Steer clear of planting them in the dense shade on the north side of buildings or under bushes, lush evergreen foliage, or thickets.

How to Plant

Plant crocus corms about 4 inches deep and 2 to 4 inches apart with the pointed end up. Someᴛι̇ɱes it can be difficult to tell which is the pointy end. If you can’t, don’t worry about it too much; the plant will grow toward the light. Adding bulb food or bone meal to the soil will ensure the plants have all the necessary nutrients. Also, plant them in clusters versus rows or border edging; they are small, delicate, and less impressive when singled out.

Appearance

Crocuses are members of the iris family. They all have deep yellow or orange powdery pistils full of pollen, attracting bees and other pollinators with their fragrance. They produce cup-like blooms that close at night.

Snow crocuses are usually the first to bloom, featuring bicolored petals like white or cream and purple with bright yellow centers. Dutch crocuses are the giants of the crocus world, even at only 2 to 4 inches tall, but featuring various colors (pinks, reds, oranges, yellows, purples, blues, and more). Purpureus Grandiflorus crocus stands out for its deep purple color. Tricolor crocus blooms feature lilac, white, and yellow bands on their petals.

Crocus Care

Crocuses fade quickly once the weather gets hot. Mix different crocuses in your garden to extend the bloom ᴛι̇ɱe. In addition, planting them where other plants will fill in and hide their foliage will help to prolong blooming and give the crocuses a chance to store energy for the next season.

As with tulips and other bulbs and corms, spring crocus corms are nourished by the dying foliage of the plants, so it’s important not to trim the leaves until they are entirely yellow. This typically occurs within six weeks after they bloom. If the crocus is planted in a grassy area, refrain from mowing it until the foliage fades, as it can deprive your plant of essential nutrients.

Light

Crocuses do best in full sun, but because they bloom early in the year with little foliage on the trees, shady spots during the summer are usually fine for spring-blooming crocuses.

Soil

Crocus plants prefer a neutral soil pH of 6.0 to 7.0 and are usually not fussy about the soil type. However, well-draining soil is crucial. As with most plants with corms as roots, crocuses do not like to sit in soggy soil, which can cause them to rot.

Water

Crocuses are generally low-maintenance plants. They like to be watered regularly in the spring and fall. The corms need water throughout the winter if there is no snow cover. However, they go dorɱaпt in the summer and prefer drier soil.

Temperature and Humidity

Crocus corm hardiness varies slightly depending on which type you are growing, but most crocuses are reliable within USDA hardiness zones 3 to 8. They bloom and survive best where winters are cold since crocus corms need 12 to 15 weeks of cold temperatures, at least 35 to 45 degrees Fahrenheit, to set their blooms. Humidity usually isn’t an issue, although excessive humidity can lead to rot.

Crocuses are often planted as annuals in climates where the winter temperatures are not sufficiently low to chill the corms. They can be purchased from vendors who pre-chill the corms at 35 to 45 degrees Fahrenheit for at least three months. You can also chill the corms yourself for the following spring by digging up the corms after the foliage has yellowed. Chill the corms in the refrigerator for at least 12 weeks before planting. However, do not store fruit in the same part of the refrigerator with the corms, as ethylene gas emitted by fruit can ruin crocus corms.

Fertilizer

Crocuses do not require a lot of fertilizer. They store their energy in their corms, so do not cut back the leaves until they turn yellow. A light top dressing of corm, bulb food, or bone meal in the fall is a good idea if you have poor soil. Try 2 cups of bone meal and 5 tablespoons of 10-10-10 fertilizer for every 10 square feet of soil. Refrain from giving fertilizer while crocuses are blooming since it can cause corm rot and flower death.

Types of Crocus

Pruning

Crocuses do not require any pruning. You must leave the green foliage intact, allow it to turn yellow, and die back naturally. The green leaves store food and pull energy into the corm to produce flowers the following winter or spring. Once the flowers fade, they’ll disappear, not requiring deadheading.

Propagating Crocuses

Crocuses are grown from corm rooting structures. They can also be grown from seed but take much longer—usually several years—to sprout from seed.

In ɱaпy areas, crocuses are somewhat short-lived, and you might need to replant them every few years. To prolong the life of your crocus corms, dig them up every three to four years in the fall. Crocuses may bloom less if the flowers clump too close together and become dense. Here’s how to dig up and divide your healthy corms:

  1. Using a hand shovel or spade in the fall, gently dig up the soil in the spot where the crocuses typically bloom. Go about three to four inches deep.
  2. Look for round bulb-looking structures that look like mini garlic heads. You may find ɱaпy cormlets or baby offsets from a parent corm. Remove them and discard the dead, rotting corms.
  3. Transplant them in another location or replant them by spacing them out at least three inches apart.

How to Grow Crocus From Seed

You can grow crocus from seed, but it can take ɱaпy growing seasons for the seeds to germinate outdoors. Scatter the seeds in the fall, barely covered with soil, in a cold frame, in the fall.

You might have a better chance of sowing the seeds indoors using a seed compost mix. Barely cover the seed with the soil mix and allow the light to reach it for germination. Keep it at 65 degrees Fahrenheit or room temperature for two to four weeks. Then, “trick” it into thinking the winter season has arrived by moving the plant to 22 to 35 F for four to six weeks. To spur germination, move it to a warmer spot, about 41 to 50 F.

Indoor germination can go perfectly and only take 30 days, or it can take six months. Outdoors, germination can occur in the spring or after several years. If grown indoors, keep them potted and growing indoors for at least three growing seasons to establish fully. By the third year, they should be ready to flower and go into the ground outdoors.

Potting and Repotting Spring Crocuses

You can grow spring crocuses in pots; however, they need adequate drainage holes, so the water doesn’t pool and cause rot on the corms. Also, give it gritty, peaty, or moderately fertile soil for faster drainage. If growing seedlings, annually transplant the seedling each fall as long as it still fits the pot. You can start with a 3-inch pot for a seed, then size up every year. Refresh all the soil with new compost each ᴛι̇ɱe.

Overwintering

These cold-hardy corms can remain inground for the winter. A light layer of fall leaves can insulate them, while a thick layer will delay crocuses breaking through the cover. If you are expecting an intense subzero freeze, you can provide more winter protection by laying down a few inches of mulch or a frost cover over the top in November. Remove heavy mulch in late January or early February so the petite blooms can poke through.

If unearthing the corms in the fall, store them in a cool, dark space over the winter. Wrap them in peat moss and put them in a paper bag, do not allow the corms to touch. Keep them in a cool space, like an unheated basement, that stays about 35 to 45 F for about 12 weeks. Plant the corm in soil with the pointy part upward as soon as you can turn it in late February or early March. Part of it can be sticking out of the ground.

Common Pests and Diseases

Crocuses are susceptible to viruses, which can cause distortions, streaking, and buds that fail to open. There is no cure for viral diseases; if they strike, dispose of the plants to prevent the spreading of the virus.

The biggest problem for spring crocus flowers and their corms is chipmunks, deer, rabbits, and squirrels may eat them. Other animals, such as skunks, may dig the corms out of the ground while searching for insects.

Liquid deterrents can be sprayed on the leaves, and granular deterrents can be scattered to prevent nibbling. You can also buy wire cages or cover the corms with chicken wire (under the soil) to protect the corms when you plant them. Avoid using bone meal if your plants are constantly harmed, as it can attract animals. Instead, try interplanting your crocuses with daffodils, which ɱaпy pests won’t touch.

Growing Crocus Indoors

Some crocus flowers have a sweet fragrance, while others have no scent. Either way, it entices bees and other pollinators who seek out this early bloomer. Forcing crocus to bloom indoors is done by “tricking” them into thinking winter has just ended and it’s bloom ᴛι̇ɱe. The gardening term for this is stratification.

To stratify potted crocus indoors, keep them in an unheated garage or basement above 32 degrees Fahrenheit but no warmer than 45 F for 12 to 15 weeks. It doesn’t require light. Only water the plant once a month. The soil should be dry to the touch before watering. ᴛι̇ɱe triggers the end of “winter” for the plant, and the corms will naturally sprout.

Once you notice sprouting, move the plant to a sunny location with at least four to six hours of sunlight. Maintain temperatures between 50 and 60 F. Gradually start introducing more water, up to once a week, only once the soil is completely dry to the touch.

Common Problems With Spring Crocus

Spring crocuses are easy to grow. They usually bloom at a ᴛι̇ɱe when insect activity and other diseases are less likely to be an issue. However, certain problems come up that can affect their growth.

No Blooms

One of the biggest complaints about crocuses is when they fail to bloom. Several factors can impact blooming, such as poor soil, firmly compacted soil, or heavy mulch covering the soil, not allowing the plant to bloom. Other compounding factors include rot or mold harming the corms or animals that have dug up and eaten the corms.

Soil issues can be remedied using a gritty soil mixture, feeding the soil with compost annually, and uncovering the mulch as winter turns the corner. Protect corms from mold or rot by keeping the corms in well-draining soil, not fertilizing the soil during active bloom ᴛι̇ɱe, and using a mesh chicken wire around the flower bed to keep rodents at bay, but allowing bees to reach the flowers.

Also, germination rates are unpredictable if you start your crocuses from seed. If you start from seed and get a seedling, it may take up to three growing seasons to produce blooms.

Crocus Flower Bed Is Diminishing

The natural lifespan of a crocus corm is about five years. However, ɱaпy create offsets or cormlets underground. These baby corms form new plants, establishing and continuing the cycle of growing into fuller corms and making more. However, the process of creating more corms also crowds the space. With crowding comes competition for soil nutrients and water. If your flower bed was once full of blooms in the spring, but that’s no longer happening, dig up the corms. Remove the dead, dying, or rotting corms. Replant them in the same spot at least 3 inches apart in compost-enriched soil.

Stunted, Distorted Growth

If your crocuses start looking sick, wilted, or have yellowing foliage early in the growing season, nematodes, worms, or mites may be underground, eating the corm or plant structures. If you dig up the corms, you will notice roots are poorly developed and decayed, or the corms look damaged. The worms are microscopic, but they can kill a plant from underground. To remedy the situation, dig up the corms, and dispose of the damaged ones. Replant them in compost-rich soil. Compost has beneficial bacteria that smother nematodes and mites.

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