Gardeners growing tiger lilies may notice peculiar black bulb-shaped structures forming along the stems between the leaves. These odd growths often cause confusion leaving plant parents wondering – are they some kind of disease? A pest infestation? Or are they actually seeds? Read on to uncover the truth about these enigmatic black blobs.
What Are Those Black Things on Tiger Lily Stems?
The small, round black structures frequently observed on tiger lily stems are known as bulbils. Bulbils are a type of modified bud that contains a rudimentary stem, leaves, and the beginnings of a root system.
So while they appear alien-like, these bulbils are actually a natural part of the tiger lily’s development. They form in the junction between the leaf and stem (known as the leaf axil).
Tiger lilies are not the only plants that generate bulbils – other lilies like Asiatic hybrids and Oriental types produce them as well. Daffodils, garlic, onions, and some begonias also grow bulbils.
What Purpose Do Bulbils Serve?
Bulbils act as a means of vegetative asexual reproduction, allowing lilies to propagate new clones of themselves without seeds.
In nature, once the bulbils mature and swell to about the size of a pea, they eventually detach and drop to the ground. If conditions are right, the bulbils will take root and develop into genetically identical daughter lily plants.
So while they contain no actual seeds, bulbils are essentially little “starter bulbs” that can give rise to brand new plant babies!
When Do Tiger Lily Bulbils Form?
Bulbils begin developing in early to mid summer. They start off green and tender, gradually enlarging and turning blackish-brown as they mature through summer into fall.
The bulbils reach peak ripeness and size just before the mother plant goes dormant for the winter. This coincides with when they detach and drop from stems, allowing them to overwinter in the ground.
So in regions with cold winters, bulbils will be most abundant on tiger lily stems during late summer through early autumn.
Can You Propagate Tiger Lilies from Bulbils?
Absolutely! Those curious black blobs provide an easy, inexpensive way to propagate more tiger lilies without buying new bulbs.
Here are some tips for collecting and growing tiger lily bulbils:
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Wait until late summer/early fall when some bulbils have started dropping. Gently twist to harvest ripe ones still attached.
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Select plump, rounded bulbils at least the size of peas. Avoid flat, mushy ones.
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Lay bulbils out to dry for 1-2 weeks. Store in a cool, dry spot over winter.
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In spring, plant bulbils 2 inches deep and 6 inches apart outdoors.
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Keep soil moist but not soaked. Bulbils will sprout within a few weeks when soil warms.
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Expect small lily seedlings the first year. Bulbils reach full flowering size in around 3 years.
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For faster results, plant in pots and grow bulbils indoors first year before transplanting outside.
Growing tiger lilies from the bulbils they so generously produce is extremely rewarding! It provides free plants, preserves hardy heirloom varieties, and allows you to clone particularly beautiful specimens.
Common Questions About Tiger Lily Bulbils
For first-timers discovering bulbils on their tiger lily stems, some questions may arise. Here are answers to a few frequently asked questions:
Are the bulbils seeds?
No, bulbils contain no seeds. They act as mini “bulbs” that can grow new cloned plants vegetatively.
Do you need both bulbils and seeds to get new plants?
No, just bulbils. Tiger lily seeds in pods are another way they reproduce, but not required.
What causes bulbils – is it a disease?
Bulbils are totally normal and healthy. Removing them prevents self-sowing but does not hurt the plant.
Should I remove bulbils to boost flowering?
Maybe. If you don’t want volunteer seedlings, removing bulbils may redirect energy to blooms. But unnecessary for plant’s health.
Can bulbils form flowers the first year?
In rare cases yes, but usually not until the 2nd or 3rd year. They need time to grow mature roots and bulb first.
Do all lily varieties produce bulbils?
No, some hybridized varieties have had this trait selectively bred out of them. But heirloom types typically form bulbils.
The Takeaway on Tiger Lily Bulbils
Those odd black blobs popping up on your tiger lily stems are not a cause for alarm. Bulbils are simply an unusual form of asexual reproduction. While they may look alien, these bulbils are totally natural for tiger lilies and certain other plants. They can be collected to propagate new cloned plants easily and for free. Just wait for ripe bulbils to start dropping, harvest plump ones, plant in soil, and let your new tiger lily babies grow!
