The water hyacinth is an invasive aquatic plant from South America that now has a wide global distribution. Although it produces a beautiful flower, its visual appeal does not outweigh the harm this plant does to waterways.
Tropical regions of South America are the original home of the water hyacinth, but it now grows in much of the warmer climates around the globe. Water hyacinth exists in the southern United States as well as parts of Africa, Australia, Asia, India and New Zealand.
The water hyacinth grows in lakes, ponds, ditches, rivers and streams, taking nutrients from the surrounding waters. The plants often link together, forming nearly impenetrable floating mats.
A member of the same family as pickerelweed, water hyacinth has green glossy leaves as tall as 8 inches and 2 to 6 inches wide. The roots extend down from the plant and branch out to form an extensive fibrous network.
The flowers of the water hyacinth develop on a spike and have six individual petals that join at the bottom to produce a tube-like bloom. The colors of these flowers range from a lighter shade of blue to violet, with some flowers being white.
As water hyacinth takes over an area it has the ability to hinder navigation, power-generation, recreational pursuits and irrigation efforts. The water beneath the floating mats become oxygen-depleted, native water plants cannot compete with them and mosquitoes breed in the conditions water hyacinths create.
Both floating and anchored water hyacinth varieties have glossy green, round leaves that can reach up to 10 inches across. Both water hyacinth species produce large pale lilac to blue-purple flowers with distinctive yellow spots.
Water hyacinth plants are susceptible to several leaf spot disease, primarily those caused by the Myrothecium roridum and the Cercospora piaropi pathogens.
The Myrothecium roridum pathogen causes narrow bands to form from the infection site to the tip of the leaves. Cercospora piaropi causes brown spots to form around the infection site on the leaves.
Water hyacinth are vulnerable to attacks from weeveils (Neochetina eichhorniae), pyralid moths (Niphograpta albiguttalis) and mites (Orthogalumna terebrantis).
The weevils, moths and mites are often purposely released in order to naturally control the water hyacinth weed. These biocontrol agents generally take between 2 to 6 years to effectively control water hyacinth growth.
Plant hyacinth bulbs in the fall, six to eight weeks before the first hard frost, when soil temperature is below 60 degrees F.
Select a sunny, well-draining location and till the soil to the depth of 12 to 15 inches, mixing a layer of 2 to 3 inches of organic matter like peat moss or decayed leaves into the soil.
Dig a hole 6 to 8 inches deep for each bulb; place the hyacinth bulb into the hole pointy end up; cover with soil.
Water hyacinth bulbs thoroughly and continue to water during dry spells throughout the fall.
Cut back the hyacinth flower in the spring when the blooms are spent; leaving the stalks and leaves to nourish the bulb.
After they have flowered, hyacinths produce the energy they need for the next season's blooms. Do not remove the plant, but cut the stems of the faded hyacinth completely to the ground. Continue to water the plants as the foliage fades naturally. Some gardeners plant other flowers to hide the foliage. Apply a general fertilizer or compost after the hyacinth flowers.
In late summer, you can dig up the hyacinth bulb and harvest the little bulb-ettes that form on the larger bulb to propagate future plants. However, it might take several seasons for these little bulbs to produce.
According to the National Gardening Association, hyacinth flowers will decrease in size after the first season. For this reason, many gardeners treat them as an annual and will replant new bulbs each fall.
Hyacinths planted in a pot generally will not produce flowers again. Once the hyacinth flowers have faded, remove the plant and bulb from the pot and discard them.
Some people with sensitive skin can develop a reaction from handling hyacinth bulbs; these people should wear gardening gloves when planting or discarding these bulbs.
Fill a 4- to 8-inch-diameter pot 2/3 full with a well-drained peat-based potting mixture. Use a pot that has at least one drainage hole in the bottom.
Set the hyacinth bulbs on top of the planting mixture, pointed end facing up. Adjust the depth of the potting mixture as necessary so that the tops of the bulbs set ½ inch beneath the rim of the pot. Space the hyacinth bulbs 1 to 2 inches apart in the pot.
Fill the pot with additional potting mixture until the tip of the hyacinth bulb is right at or just beneath the soil surface.
Water the potting mixture from the top until the water begins to drain out of the bottom of the pot. Set the watered pots in a location whose ambient temperature is 35 to 45 degrees F for 13 weeks.
Bring the plants out of cold storage and place them in a 60-degree-F room where they can receive bright, direct sunlight. Water as necessary to keep the soil moist but not soggy.
Move the hyacinth to a bright area that receives indirect sunlight once the flowers begin to bloom.
Fill a hyacinth vase with water to the waist. The waist of the vase is where the vase narrows near the middle.
Set the flower bulb in the vase so the bottom of the bulb is just touching the top of the water. The bottom of the bulb rests just above the waist of the vase.
Place the vase in a dark 50 degree Fahrenheit room for four to eight weeks, or until the roots develop. Add more water to the vase as needed to maintain the water level.
Move the vase to a 68 to 70 F room near a brightly lit window once the roots are formed and after the stalk begins to emerge from the top of the bulb. Continue to replenish the water level as needed.
Rotate the vase every two to three days so the stalk grows straight and doesn't lean toward the light. Move the vase away from the window so it receives bright, indirect light once the flowers open, as this helps prolong bloom.
Plant hyacinth bulbs in the fall, at least two months before the first frost, spaced 18 inches apart with the tip of the bulb pointing skyward in a bed rich in organic matter. Water thoroughly immediately after planting unless you are expecting a heavy rain, in which case watering the bulbs will be unnecessary.
Water the hyacinth weekly as soon as you notice the shoots emerging from the ground. You should not saturate the soil; hyacinths will not benefit from over watering and may in fact become rotten.
Check on your hyacinth daily after it blooms. Often the blooms become tall (6 to 12 inches) and heavy, so you may have to support them with some type of trellis.
Water the flowering hyacinth once weekly to a depth of 1 inch around the base of the stems. Use a watering can for best results; when high pressure is applied with a hose it can cause the flowers to fall off the plant.