Grape hyacinths rise in early spring with sweet little clusters of purple and sometimes white flowers. They are prolific bloomers which naturalize easily and arrive year after year. The plants can get out of hand over time and removal is a process that requires persistence. Fear not. There is a method and a plan for removing grape hyacinths.
Grape Hyacinth Weeds
Grape hyacinth produces numerous seeds once the blooms are spent and bulbets are formed off the parent bulbs for future flowers. This allows grape hyacinth plants to spread rapidly and sometimes out of control. Grape hyacinth weeds infest untilled fields and garden beds alike and may rely upon sequential grape hyacinth control for complete removal.
Most grape hyacinth bulbs are planted on purpose with the intention of brightening up the front path or spring flower bed, but the ease with which this plant reproduces can make it a real nuisance in some instances and its invasive abilities are a threat to crop land.
Grape hyacinth control will necessitate the removal of seed heads before they produce viable seed and extraction of as many bulbs as possible. Because the plants are able to make many tiny bulbs off the main one, it can be almost impossible to find them all in a season. Complete elimination may take years.
Grape Hyacinth Control
The first step to get rid of grape hyacinth is to remove seed scapes after the flower petals have fallen. Although it takes at least 4 years for the little seedlings to form flowers, the seeds will eventually restart the hyacinth take over.
Pull the leaves as well, as these are giving solar energy to turn to starch, which is then stored for the next year’s growth in the bulbs and bulbets. Normally, leaving the foliage until it has died back is recommended, but in this case, it is just adding fuel to the fire. You can also use a propane weed torch and burn off the greens. This method will require several years for complete success but eventually the plants will die.
Getting Rid of Grape Hyacinth Bulbs Manually
Removing grape hyacinths manually is a bit of a chore but works better than herbicide use. This is because the bulbs and bulbets have a waxy coating which helps protect them in winter, but also erects an effective barrier against chemicals. Dig at least 6 inches down and pull out as many of the bulbs as possible.
Removing grape hyacinths completely is a challenge because it is hard to spot every single bulb. If you want to be meticulous, allow the foliage to grow in spring and then follow each and every leaf to its bulb or bulbet source. That is a bit intense for most gardeners, so some follow up is usually necessary the following season and possibly even the next.
Chemical Warfare to Get Rid of Grape Hyacinth
A 20 percent horticultural vinegar applied to the leaves will kill the foliage, leaving the bulbs weak. A better way to get rid of grape hyacinth is with glyphosate, which is found in many weed killers including Roundup. It is systemic, so you will actually need to leave the foliage untouched on the plants.
Spray at the rate recommended on the bottle on a windless, mild day. Be careful because this method of grape hyacinth control is non-specific and can kill other plants if the chemical spray gets on their leaves.