Modern hyacinths are some of the easiest-to-grow perennial spring bulbs. Hyacinths will come back every year, though their flowers will diminish in vigor after a few seasons. They are best planted in the fall and have a moderate growth rate. Hyacinths can grow outdoors in the ground or pots, as well as indoors in a bulb vase filled with water. Please be careful and keep them out of the reach of kids and critters: The bulbs are toxic to humans and pets. Most varieties of hyacinth bulbs are fairly large. For spring garden blooms, plant hyacinth bulbs in the fall six to eight weeks before the first frost. They should be placed root end down (widest side down) about 4 to 6 inches deep. Give them some room to spread out by spacing them about 3 to 6 inches apart. Cover with soil, and water well. Taller varieties can tend to flop. You can stake them if you only have a few, or plant them closer together so that they support one another.
Light
Hyacinths like full sun to partial shade. Aim to give the plants at least six to eight hours of sunlight a day. As with all spring bulbs, hyacinths sprout, bloom, and start to fade before deciduous trees fully leaf out, so you don’t have to worry about too much shade from nearby trees.
Soil
Hyacinth bulbs are not particular about soil pH, but they prefer a slightly acidic to neutral soil. They also do best in soil that is loose and well-drained; they will not tolerate wet soils. Rich soil can lead to floppy stalks, so go easy on the organic matter when preparing or amending the soil.
Water
Water the ground well after you plant the bulbs. Continue watering into winter if there is no regular rain, but allow the ground to dry out between watering. If the bulbs sit in cool, wet soil, they will eventually rot. Check the ground by sticking your finger in, and water only when it’s totally dry. Usually, this is once or twice a week, depending on your climate. Generally speaking, about 1/2 inch of water per week—combined irrigation and rainfall—will be sufficient for hyacinths. But this depends on how well the soil drains.
Temperature and Humidity
Hyacinths can be expected to survive the winter in USDA plant hardiness zones 4 to 8. They might need some winter protection in colder zones and some pre-chilling in warmer zones, depending on the variety. In zones where winter temperatures remain above 60 degrees Fahrenheit, dig up the bulbs and chill them somewhere dark and cold for six to 10 weeks before replanting.
Fertilizer
The easiest way to feed new bulbs is to toss some bulb food into the hole at planting time. There are many fertilizers available for feeding bulbs—10-10-10 is recommended—or you can use an ordinary bone meal. Feed the bulbs a mere handful at planting and again in the spring when the new growth first appears by scratching some bulb food into the nearby soil and watering well. For the amount to use, follow the product label instructions.
Types of Hyacinth
Modern hyacinths come in many colors. Some varieties include:
‘Hollyhock’: Offers striking reddish-pink double blooms’Pink Pearl’: Has fuchsia petals that are edged in pale pink’Woodstock’: Boasts deep plum petals’Blue Jacket’: Features a denser bloom structure and deep purple-blue flowers’Top White’: Offers bright white florets that are star-shaped
How to Force Hyacinth Bulbs
It’s possible to force hyacinth bulbs indoors into early blooming. Simply plant a bulb in a container filled with well-draining potting mix, ensuring that the container also has drainage holes. The bulb tip should be just above the soil line. Place the container in a dark spot that remains between 33 and 45 degrees Fahrenheit. Allow it to sit there for at least 10 weeks as roots develop. Green shoots will also start to grow. Once the shoots grow to around an inch, start to slowly increase light and warmth. Water to keep the soil lightly moist but never waterlogged, and avoid hitting the shoots when watering. Once the plant has buds, move it to a sunny window with bright, indirect light to wait for your flowers to open.
Pruning
Once the bulbs have finished blooming, cut off the flower stalks but allow the leaves to remain. This will encourage the plants to store energy in their bulbs for next season.
Propagating Hyacinth
Like most perennial bulbs, hyacinths are best propagated by splitting offset bulbs from the parent plant in the fall. This method can take two or three years before the bulblet grows to a size sufficient to produce large, vibrant flowers. Thus, propagating hyacinths is an activity best practiced by serious enthusiasts. Here’s how to propagate hyacinths by splitting off the offset bulbs:
How to Grow Hyacinth From Seed
While hyacinths can be propagated from seed, it can take several years to coax the seed into creating a bulb and to nurture the bulb into a sizable structure that will produce a flowering plant. First, you’ll have to allow your hyacinth blooms to remain on the plant to form seed pods. These pods will ripen from green to tan as they form small black seeds inside. The pods will dry and split open; you can catch the seeds by putting a white sheet under the plant or wrapping pantyhose around the flowers themselves. Separate out the seeds, and soak them in warm water for one to two days. Then, place them between two moist paper towels in a plastic bag, and put them in the refrigerator to sprout. Once they’ve sprouted, slightly press them into a seed tray filled with moist seed-starting mix, and place them in a cold frame or greenhouse to continue growing.
Potting and Repotting Hyacinth
When planting in pots, either plastic or clay will do as long as they have good drainage. The container should be roughly 6 inches deep. The width of the container depends on how many bulbs you are planting. Hyacinth bulbs in pots can be spaced more closely than when planting in the ground because the bulbs won’t need room to multiply. You can squeeze them in so they are almost touching, but leave room for some soil in between to hold water. Repotting should not be necessary if you have properly spaced your bulbs. Ordinary commercial potting soil is fine for planting hyacinths in containers, though some people like to blend in a little sand with the potting mix. Keep the potting medium damp but not soaking wet until the bulbs sprout. Then, water whenever the soil dries out. Once the bulbs have sprouted, move them to indirect sunlight. Cool temperatures will keep them in bloom longer.
Overwintering
In colder zones (USDA zones 2 and 3), applying a thick layer of mulch over the bulb bed can allow hyacinth bulbs to survive cold winters. You also can position the bulbs an inch or two deeper at the time of planting to help insulate them. In zones 4 to 8, no winter protection should be necessary. However, if your hyacinths are outdoors in containers, cover them or move them to a sheltered spot to prevent the containers from accumulating too much moisture and rotting the bulbs. If you are growing hyacinths in zone 9 or above, where winter temperatures stay above 60 degrees Fahrenheit, you will need to dig up your bulbs and chill them artificially before replanting. Store them in a mesh bag in a cool, dark spot that remains above freezing but below 45 degrees Fahrenheit for 10 weeks minimum.
Common Pests & Plant Diseases
All kinds of rodents will munch on hyacinth bulbs. You can give them some protection by throwing a handful of gravel into the planting hole, or you can try commercial rodent deterrents. An easier method is to interplant them with daffodils, which rodents tend to avoid. Few plant diseases affect hyacinth, but the bulbs can rot when planted in dense soil that doesn’t drain well.
How to Get Hyacinth to Bloom
Hyacinth bulbs are generally low-maintenance and bloom quite easily on their own in the spring. That being said, you can give yours a leg up by cutting down the flower stalk when this year’s blooms fade. Then, when its leaves turn yellow, cut them away as well. Feed them once they bloom, and again in August, to give them a boost for the following spring. But be aware that most gardeners find it necessary to replant hyacinths (or lift and divide them) every two or three years to keep them blooming robustly. Like many hybrid bulbs, hyacinths lose their vigor rather quickly.
Common Problems With Hyacinth
The hyacinth is a reliable plant that will give you several years of aromatic blooms, but occasionally there are unfortunate issues.
Spotted Foliage
If you’ve had a late frost after the foliage has appeared, hyacinth leaves can develop disfiguring spots. Sadly, there is not much you can do about it, but in some cases it will not affect the flower stalks that later appear.
Broken, Streaked Petals
Broken and streaked petals can be caused by mosaic virus, which also can cause mottled leaves. Infected plants will need to be dug up and thrown away. Sterilize any tools you use to do this; they, too, can spread the disease.
Small Flowers
It is normal for hyacinths to bloom less robustly with every subsequent season. You can prolong their lifespan by regular feeding. Propagating new plants by dividing mature hyacinths can keep you in blooming plants almost indefinitely.
