Types of Seedling Trays

Plug Seedling Trays

Plug seedling trays are the most widely used type of tray for starting seeds.

They contain multiple individual cells that allow each seedling to grow separately. This design prevents roots from tangling and makes transplanting easier.

Plug trays are commonly used for:

• vegetables

• flowers

• herbs

• greenhouse crops

Typical plug tray sizes include:

• 50 cell trays

• 72 cell trays

• 105 cell trays

• 128 cell trays

• 200 cell trays

Trays with fewer cells provide more space for root development, while trays with more cells are ideal for starting large quantities of small seedlings.

Deep Cell Seedling Trays

Deep cell trays are designed with deeper compartments that allow roots to grow longer before transplanting.

These trays are commonly used for plants that require a longer nursery period or stronger root systems.

Deep cell trays are often used for:

• tree seedlings

• tomatoes

• peppers

• cucumbers

• outdoor vegetable crops

The additional depth supports stronger root development and helps reduce transplant shock when seedlings are moved to the field.

Flat Propagation Trays

Flat trays do not contain individual cells and are often used as support trays.

They are commonly placed underneath plug trays to hold multiple trays together and make watering and transportation easier.

Flat trays are widely used in greenhouses because they simplify seedling management and help keep growing areas organized.

Heavy Duty Nursery Trays

Heavy duty trays are designed for commercial nursery production where trays must be reused many times.

Compared with standard trays, heavy duty trays feature:

• thicker plastic material

• stronger structural support

• longer service life

These trays are commonly used by large plant nurseries and commercial growers who require durable equipment for repeated planting cycles.

Vacuum Formed vs Injection Molded Trays

Seedling trays are generally manufactured using two main production methods.

Injection Molded Trays

Injection molded trays are thicker and more durable. They are designed for repeated use and long-term greenhouse production.

Benefits include:

• stronger structure

• longer lifespan

• improved durability during handling and transport

These trays are often preferred by professional nurseries and commercial growers.

Vacuum Formed Trays

Vacuum formed trays are lightweight and cost-effective. They are commonly used for short production cycles and large-scale seed starting.

Advantages include:

• lower manufacturing cost

• lightweight design

• efficient large-scale production

However, they may be less durable compared with injection molded trays.

How to Choose the Right Seedling Tray

Choosing the right tray depends on several factors.

Important considerations include:

• plant type

• root development requirements

• greenhouse space

• transplant schedule

• tray durability

For example:

• leafy vegetables often use high cell count trays

• fruiting vegetables require larger cells

• long nursery cycles benefit from deeper trays

Selecting the correct tray type improves plant health and helps growers optimize production efficiency.

Conclusion

Seedling trays come in a wide range of designs, cell sizes, and materials to meet different plant propagation needs.

From plug trays for vegetable seedlings to heavy-duty nursery trays for commercial production, each tray type plays an important role in efficient plant cultivation.

By understanding the differences between seedling tray types, growers can select the best solution for their greenhouse, nursery, or agricultural operation.

Frequently Asked Questions

What are the most common seedling tray types?

The most common seedling tray types include plug trays, deep cell trays, flat propagation trays, and heavy-duty nursery trays. Each type is designed for different plant growing requirements and nursery production systems.

What is a plug seedling tray?

A plug seedling tray is a tray with multiple small cells used for starting seeds. Each cell holds a single plant, allowing roots to grow independently and making transplanting easier.

Are seedling trays reusable?

Yes. Many commercial seedling trays are reusable, especially heavy-duty or injection molded trays. Proper cleaning and storage can extend their lifespan for multiple growing seasons.

How do I choose the right seedling tray size?

The right tray size depends on the plant type and how long the seedlings will remain in the tray. Small cells are suitable for herbs and leafy greens, while larger or deeper cells are better for vegetables that require stronger root systems.