The science of seedlings, sprouts, and other small plants

October 14, 2026

By Jon Letman, Tropical Editor

In the earliest stages of a plant’s life, when it transforms from a seed to a sprout or a spore to a sporeling, it holds its greatest potential but is also in its most vulnerable state. A new plant’s primary function is to establish roots and leaves so that it can manufacture chlorophyll that captures sunlight enabling it to produce glucose (basic sugar). Whether in soil, on a tree, a rock, or other surface, young plants must capture sunlight and moisture in order to grow. They are what NTBG’s senior research botanist Dr. David Lorence calls “little growth machines.”

Under favorable conditions, a seed’s embryo will produce an initial root called a radicle which anchors the seed to the earth where it seeks nutrients and water. As the radicle burrows deeper into the ground, a shoot apex rises toward the sunlight to produce false leaves called cotyledon which are followed by the first true leaves. During this early phase of plant life, the seed’s endosperm contains nutrients to nourish the emerging plant until it can photosynthesize light to make its own food.

But young plants face peril in the form of predators (insects, snails, rodents) and pathogens, competition for space and resources from other plants, and environmental factors such as too much or too little moisture, or the risk of being trampled or crushed. The likelihood of a young plant’s survival, Dave Lorence says, is often quite small.

Blowing in the wind   

Not all plants start as seeds in the ground. Bananas, gingers, and heliconia spread underground as rhizomes while orchids and tillandsias, for example, produce wispy, light-weight seeds that float like feathers, dispersed by wind which carries them onto the surface of trees, rocks, and manmade objects where they germinate.

In south Florida, where bromeliads are common, Dr. Brian Sidoti, director of The Kampong, along with colleagues and interns₁ are studying the reproduction and growth rate of native bromeliads like the giant airplant (Tillandsia utriculata) which grows on tree branches and trunks.

Today, in Florida some native bromeliads are threatened by a weevil (Metamasius callizona) which can destroy giant airplants that can grow up to two meters from its base to the tip of the inflorescence over the course of 15 to 20 years. This species is known to produce as many as 33,000 seeds from a single mother plant before it dies. Interns working with NTBG, are conducting viability and germination trials to better understand survivability and the pressure posed by weevils and other threats. 

“If a weevil were to attack the bromeliad before it reaches reproductive maturity, then that plant dies and tens of thousands of potential new individual plants would be lost,” says Brian.

Weevils and other insects, along with habitat loss and changing climate conditions continue to threaten these distinctive plants that are an integral part of Florida’s natural landscape.

Time as a threat

Another challenge young plants face is time. Some plants — Melicopes, for example — may take a year or more to germinate. Other seeds take even longer and when seedlings finally emerge, they face predators, larger, aggressive plants, and the struggle to get sunlight and water. Because young plants lack biomass, they are more vulnerable, says NTBG seed laboratory manager Jena Osmani. With fewer leaves and branches to draw energy from, small plants are more susceptible to drought whereas larger, more mature plants have greater capacity to store moisture and energy in their more developed stems, leaves, and root systems.

Jena says that unlike common domesticated food crops, many native Hawaiian plants possess a specialized dormancy mechanism meaning they may take longer to sprout and rely on environmental cues such as temperature or moisture level or even chemicals released in a fire before they germinate.

NTBG’s seed lab staff conduct ongoing seed germination tests that produce thousands of tiny native Hawaiian plants. Because many of these are rare or endangered, the seedlings are not discarded but instead painstakingly transferred from a petri dish to soil and then moved to NTBG’s horticulture and conservation center where they can be grown out and eventually used for our living collections and restoration projects.

Seed bank and laboratory technician Amme Kekuna spends much of her time meticulously conducting this work, transplanting seedlings, providing species-specific care based on the conditions of their wild habitat. This determines if they should go into the greenhouse or be temporarily put under grow lights inside the fern lab for greater protection. For seedlings accustomed to cooler, higher elevation habitats, it can be more difficult to survive in a hotter environment like the Lāwa‘i Valley.

When Amme sees an adult plant she knew as a sprout she thinks, “It’s so fun to see what they look like in their mature version. It’s like, I saw you when you were an inch high. It’s weird to see you now twelve feet tall!”

Jena’s work with seeds has changed her perspective on the natural world. She now takes more time to observe the quality and composition of forests, noticing the balance between native, introduced, and invasive species. Expressing her greater appreciation for healthy native forests, Jena recalls one recent visit to the Lower Limahuli Preserve where she encountered four large hōlei (Ochrosia kauaiensis) mother trees that had produced a healthy population of more than a hundred saplings. Seeing all those tiny plants filled her with joy and excitement.

Healthy forest families

Dr. Uma Nagendra, Limahuli Garden and Preserve’s conservation and operations manager, finds the early stage of plant life fascinating because every plant experiences it in some form. She notes how young plants must develop adaptations to counter threats and disturbances and how their appearance can change with age — not only size — but certain attributes, for example leaf color. A young plant which is more vulnerable to solar radiation or predation by herbivores may change colors. For example, ferns which are red or crimson when young will turn green with age. Some plants produce larger leaves when they are young as an adaptation to survive in dense forest canopy but later grow proportionately smaller leaves as the plant matures.

Leading a team that does native forest restoration in the Lower Limahuli Preserve, Uma says they try to create conditions most favorable for seedling survival. Ideally this means a protective canopy without too much sun or impenetrable shade and a forest floor conducive to growth. Seedlings have the best chance of survival in soil that doesn’t bake in the sun or wash away in the rain. A good native understory can help protect soil and an abundance of moss allows for better moisture infiltration, slowing down water flow and creating micro-habitats and protective pockets that collect seeds and nutrients.

Depending on the species, surrounding mature plants can benefit or hinder a seedling’s growth. Uma explains that if a young plant can tap into the mycorrhizae or microbiome of another plant, it can help them survive but if pathogens are present, the impact can be detrimental. For many plants, she says, they need to be in the “Goldilocks zone” where they are not too close or too far from mature trees. 

Once a plant passes that early stage and has developed root stock or rhizomes to draw from, it’s more likely to withstand stress or damage. Uma adds that while it is generally better to get plants from the nursery into the wild sooner than later, if they are outplanted too soon, disturbing the roots can cause shock. 

Whenever Uma finds herself beneath a canopy of adult trees, she searches the ground for seedlings or saplings which will eventually fill the space of older trees. “If there’s not a younger population to replace them, there’s a time limit on the forest.” Finding baby plants is so heartening, Uma says, “because regeneration is not something we want to take for granted ever.”

Tiny green worlds 

One of the most important non-seed-bearing plant groups are ferns which produce spores that grow into tiny structures called gametophytes which in turn produce the egg and sperm that, when fertilized, develop a tiny sporophyte that eventually grows into what is recognizable as a fern.

Speaking from inside NTBG’s fern laboratory on Kaua‘i, fern lab manager Natalie Blum explains that the process of a spore becoming a sporophyte and reaching maturity can take months or even years and keeping the gametophyte moist is key to their survival. Holding a translucent plastic tray the size of a tofu container, Natalie shows off a tiny hāpu‘u (Cibotium glaucum) — a native tree fern which can grow to ten feet tall. Collected as spores in the Limahuli Valley, these gametophytes are only five millimeters wide.

Because gametophytes are easily contaminated by algae, fungi, microbes, and weedy spores, fern lab staff must remain vigilant to minimize the threat of contamination. Natalie says that because gametophyte fertilization generally takes longer to see results, she has gained a deep sense of appreciation for the process required to produce even a single sporophyte.

Working closely with Natalie is long-time NTBG research associate Dr. Ruth Aguraiuja who specializes in native Hawaiian ferns. Ruth says people may see them inside the fern lab hunched over small trays for hours on end and wonder what they are doing, but insists working in this “microworld” is very rewarding.

“There’s so much beauty in how ferns grow with different structures. Connecting microscope surveys to field surveys in a natural habitat provides a lot more information and a better understanding of fern life,” Ruth said.

Whenever you walk in a forest, she says, every patch of moist earth or fallen log may hold countless ferns in early-stage development. Under the right conditions, the fern life cycle will continue to produce new ferns to carpet the forest, benefiting other plants, fostering growth and creating healthier, more diverse habitats.

For humans, busy with our daily lives, even if we are surrounded by plants, it’s easy to forget just how miraculous and unlikely it is that so many plants defy the odds, overcome the obstacles, and grow from tiny green specks into forests, grasslands, and countless plant-filled habitats that support other forms of life, providing much of what sustains us and makes our planet a home.

[1] Colleagues from Colorado College, Rhodes College, New York Botanical Garden, University of Connecticut and Florida International University interns