How To Grow And Care For Hyacinths

Hyacinths (Hyacinthus orientalis) are beautiful additions to Southern gardens. They provide vibrant floral color with tall spikes of eye-catching blooms and bright green foliage. Hyacinths are members of the Asparagaceae family. They're perennials that produce striking, fragrant flowers, which will have you looking forward to their blooms every year. Read on to learn about hyacinths and how to plant, tend, and maintain them everywhere, including in your gardens, containers, and windowsills. 

Hyacinthus orientalis, or the common hyacinth, is a fragrant flowering plant that blooms early to mid-spring. Hyacinths produce showy flowers in shades of blue, purple, white, pink, and red. The flowers appear in thick clusters on tall spikes—each spike has small, deeply fragrant, bell-shaped blooms. Long bright green leaves form around the base of the plant.

However beautiful, hyacinth bulbs can cause skin irritation. The plant's bulbs are partly composed of calcium oxalate crystals, which act like invisible barbs. They can create microscopic breaks in the skin that cause itching and irritation, so be sure to wear gloves or wash your hands thoroughly after handling bulbs and before touching your skin, face, or eyes. Hyacinths are also toxic to pets.

Plant Attributes

Hyacinth Care

Plant hyacinths in well-drained soil. According to The Southern Living Garden Book, gardeners should "set larger Dutch hyacinth bulbs 6 inches deep, 5 inches apart. Set smaller ones and Roman hyacinth bulbs 4 inches deep, 4-5 inches apart." The bulbs grow best in full sun or partial shade with regular watering during the growth and blooming periods.

To tend to already-planted hyacinths for next year's blooming season, fertilize the plants as their blossoms droop and fall. Snip faded spikes and continue watering the bulbs until the foliage yellows and dies back.

Plant bulbs in autumn, putting them in the ground from October to December for flowering in the spring months (usually March and April). They're perennials, but you can treat them as annuals. According to The Southern Living Garden Book, the "size of the flower spike is directly related to the size of the bulb. The biggest bulbs are desirable for exhibition plants or for potting; the next largest size is satisfactory for bedding outside. Small bulbs give smaller, looser clusters with more widely spaced flowers."

Light

Grow hyacinths in full to partial sun. Hyacinths need at least six to eight hours of daily sunlight, but providing these flowers with afternoon shade in areas with prolonged sun exposure is beneficial. As an early-blooming spring bulb, these plants will likely not compete for sun exposure from overhanging deciduous trees.

Soil

While not particular about soil pH, hyacinths best tolerate slightly acidic to neutral soils. Soil should be loose, moderately fertile, and well-draining. Hyacinths will not tolerate wet or very nutrient-rich soil—this causes the bulbs to rot and the stalks to be floppy.

Water

Keep a consistently moist but well-draining soil. Do not overwater the ground or container to avoid rot and diseases. Relying on rainfall is best, but if not possible, provide plants with about a half inch of water weekly. Use your hand to feel the soil to keep it moist, and water again when the top few inches are dry.

Temperature and Humidity

Hyacinths prefer colder temperatures as early spring bloomers, needing exposure to temperatures between 40°F to 45°F for at least three months. The bulbs need cold exposure, so if temperatures do not drop to 60°F or below, dig up the bulbs and keep them in the dark and a cold area for at least six to 10 weeks before replanting.

Moderate climates need to plant hyacinth bulbs four to five inches deep, while colder environments need bulbs planted about six to seven inches deep. Hyacinths prefer low humidity.

Fertilizer

After planting, add a bulb-specific, slow-release, granular fertilizer, such as a 10-10-10. Add the fertilizer to the soil before planting to help promote healthy hyacinth growth. Add a second fertilizer after the initial blooms on the soil's surface and repeat in the fall.

Types of Hyacinths

Hyacinths are available in various colors—some better suited for warmer Southern climates. Here are some selections to know:

• H. orientalis 'Blue Jacket': This variety features big columns in a royal blue color with white edges. 
  
• H. orientalis 'City of Haarlem': This heirloom variety features soft petals in primrose yellow that mature to a creamy white. 
  
• H. orientalis 'Pink Pearl': This variety features a cotton-candy-colored rose-pink flower.
  
• Muscari armeniacum 'Grape Hyacinth': This variety features densely-formed, small, delicate cobalt-blue flowers. 

Pruning

Keep hyacinth leaves intact for as long as possible, even after the plant finishes blooming. After the flowering seasoning, trim hyacinth plants to just above the bulb and roots to help them conserve energy for the following season. Remove any dead or diseased foliage near the bulb's base. Store hyacinth bulbs in a cool, dry, and dark location until it's time to plant the following season.

Propagating Hyacinths

The best method for propagating hyacinths is dividing offset bulbs from the main bulb. Here is how to propagate hyacinths through bulb division: 

• In the fall, select a mature hyacinth plant to propagate. Carefully dig around the plant to remove it from the soil. Bulblets might extend beyond the parent plant's bulb. (Use protective gear to avoid skin contact with the bulbs.)
• Gently remove excess soil from the hyacinth bulb. Locate the main or parent bulb.
• Separate bulblets from the parent bulb using your hands. 
• After separating the bulbs, replant them in well-draining soil. Use a balanced, bulb-specific fertilizer to assist with plant development. 
• Depending on the size of the bulblets, hyacinths will flower the following spring for larger bulbs or two years after planting for smaller bulbs. 

How to Grow Hyacinths From Seed

Growing hyacinths from seed is more challenging than propagating them from bulb divisions. It may be years before seeds are viable for planting. To grow hyacinths from seeds, here is what you need to know:

• Start by removing hyacinth seeds from a healthy, mature plant bloom after the flowers have faded for the season—Seed pods emerge after hyacinths bloom and mature from green to tan. 
• After the seed pods dry and split open, remove the seeds and soak them in clean water for up to two days. 
• Place seeds on a wet paper towel in a plastic bag and place them in the refrigerator until it's time to plant. 
• If planting seeds immediately, fill a seed-starting tray with a moist potting mix and spread them evenly throughout—Cover the seeds.  
• Keep the seed-starting tray in a cold environment or greenhouse for up to a year so the plants can sprout. 
• Transplant sprouted seedlings to their final location after a year.

Potting and Repotting Hyacinths

Hyacinths are excellent container plants and look lovely when planting many of them in close proximity. They require good drainage when planted in pots. At first, they grow best in a porous potting mix shaded and cooled by a layer of mulch at the surface. With enough shade, the roots will form, and then, after the bulbs take root, the hyacinths need plenty of sunlight (plus a consistent environment of well-drained soil).

You can force hyacinth bulbs into a vase. All you need to do is place chilled bulbs (pointed side up and root end down) in a forcing vase and ensure the water comes all the way up to the bottom of the bulb. Then, place the bulbs in a cool, dark place until the roots develop and the plant's leaves appear. Be sure to change the water regularly and keep the water level consistent. When the leaves appear, move the vase to a bright spot, like a windowsill, where they can receive full sunlight and warmer temperatures. The forced hyacinths will flower in six to eight weeks. However, the bulbs will likely not rebloom.

Overwintering

Depending on your climate, hyacinth bulbs require some winter care. Adding a thick layer of mulch over the soil's surface in colder environments helps insulate the hyacinth plants to protect them from harsh winter weather. Try mixing bark chips, straw, or evergreen boughs as mulch.

If growing hyacinths in containers, move them into an area that protects the bulbs from excessive moisture or harsh weather. The bulbs will rot if hyacinth plants experience too much moisture. Hyacinths need cold exposure to bloom the following year, so in areas with seasonably warm winters, dig up the bulbs and place them in a bag to store them in a cool, dark location. Hyacinth bulbs need exposure to temperatures above freezing for at least 10 weeks for roots to develop—at least 45°F or above.

Common Pests & Plant Diseases

While relatively low-maintenance plants, hyacinths are still susceptible to some pests and diseases. Some pests include aphids, caterpillars, slugs, and snails. Removing these infestations by hand is beneficial and might be enough to prevent these pests from spreading. Treat aphids with a garden hose or lighting spraying insecticidal soap.

Hyacinth bulbs are susceptible to rot, often occurring from oversaturating the soil. Fungi also impact hyacinth development when soil-borne diseases like Botrytis blight spread in plants without proper air circulation or in moist, humid environments. Treat with fungicides and maintain healthy foliage to prevent the disease from spreading. 

Common Problems With Hyacinths

While easy to grow and care for, hyacinth plants still have some common problems to be aware of so you can treat them properly:

Drooping Leaves

Hyacinths can suffer from overexposure to warm temperatures. When growing hyacinths, especially indoors, ensure moderately cool temperatures to avoid stems from growing too fast, which causes the plants to become top-heavy and fall over. 

Fewer Blooms

Hyacinth plants require you to divide the bulbs every two to three years to avoid overcrowding. Overcrowding can cause the blooms to appear less ample. Allow plants to die down naturally and avoid removing the plant's green foliage. Hyacinths need this foliage to provide energy for the following season's blooms. Use a slow-release fertilizer to encourage healthy development.