Seeds, Plugs, Bulbs, Tubers & More: Understanding How Flowers Begin

When people visit a flower farm, they often assume every flower begins the same way—with a seed. While many plants do start from seed, flower farmers actually grow plants using several different methods. Each method has its own advantages and is suited to different types of plants.

Understanding these differences helps gardeners know how plants grow, why some flowers appear earlier than others, and why certain plants must be stored over winter in colder climates like Northern Illinois.

Let’s take a look at the most common ways flowers begin.

1. Seeds

Seeds are the most basic and natural way plants reproduce. Inside every seed is a tiny embryo plant along with stored energy to help it begin growing once it has moisture, warmth, and light.

Flower farmers start thousands of plants from seed each year because it is cost-effective and allows access to many unique varieties.

Examples of flowers commonly grown from seed include:

• Zinnias

• Cosmos

• Snapdragons

• Basil

• Larkspur

Seeds can be started directly in the garden or indoors using trays or soil blocks to give plants a head start before transplanting outside.

PHOTO: Examples of using the soil blocking method for seed starting.

To learn more about soil blocking, come to our Workshop on March 28th at the farm. See details HERE.

2. Plugs (Seedlings Started by Growers)

Plugs are young plants that have already been started from seed by professional growers and are sold in trays ready to transplant.

They are extremely popular with flower farms because they:

• Save weeks of germination time

• Provide very uniform plants

• Reduce early seedling losses

Many farms purchase plugs for flowers that are slow or difficult to germinate, such as:

• Lisianthus

• Eucalyptus

• Some perennial flowers

Think of plugs as “teenage plants” since they’ve already made it through their fragile baby stage.

3. Bulbs

A bulb is an underground storage structure that contains everything a plant needs to grow and bloom. Inside a bulb are layers of plant tissue packed with nutrients.

Bulbs allow plants to survive winter underground and quickly send up shoots when conditions are right.

Common flower bulbs include:

• Tulips

• Daffodils

• Hyacinths

• Alliums

Bulbs are typically planted in fall so they can bloom the following spring.

We will offer beautiful spring tulips in our BLOOM CLUB. See our website for details.

PICTURE: A stunning premium bouquet from our Spring Bloom Club.

4. Tubers

Tubers are thick underground stems that store energy, but unlike bulbs they do not have layered structures.

They grow new shoots from small points called “eyes.” The most famous flower grown from tubers is the dahlia.

Examples of tuber plants:

• Dahlias

• Tuberous begonias

• Caladium

In colder climates, tubers are dug up in fall and stored indoors over winter to protect them from freezing.

PICTURE: An example of a large dahlia tuber that was stored over the winter.

5. Corms

Corms are often confused with bulbs, but they are actually solid underground stems rather than layered structures. They grow new corms each year as the plant develops.

Examples include:

• Gladiolus

• Crocus

• Ranunculus

Flower farmers often plant corms in succession to ensure continuous blooms.

6. Rhizomes

Rhizomes are horizontal underground stems that grow sideways beneath the soil, sending up shoots along their length. This growth habit allows plants to spread naturally.

Examples include:

• Bearded iris

• Lily of the valley

• Canna lilies

Rhizomes are typically divided every few years to keep plants healthy.

7. Cuttings

Some plants are grown by taking a piece of an existing plant and encouraging it to grow roots. This method ensures the new plant is genetically identical to the parent plant.

Common flowers propagated by cuttings include:

• Dahlias

• Geraniums

• Coleus

• Chrysanthemums

Cuttings are especially useful for maintaining specific varieties with desirable traits.

Why Flower Farms Use Many Methods

Professional flower farms rarely rely on just one propagation method. Instead, they combine several approaches to achieve the best results throughout the growing season.

For example, a single flower farm might grow:

• Seeds for annual flowers

• Plugs for slow-growing varieties

• Bulbs for early spring blooms

• Tubers for summer flowers like dahlias

• Corms and rhizomes for specialty crops

Each method plays a role in creating the continuous waves of flowers that make a farm come alive from spring through fall.