Benefits of Using Plug Trays for Nursery Raising

Walk into any modern commercial nursery today and you’ll likely see rows of neat, multi-celled plastic trays, each housing a single seedling growing in a clean, soil-free medium. This is the plug tray nursery system – and it has fundamentally changed how growers raise planting material. Whether you are producing tomatoes, chillies, chrysanthemums, or cuttings of ornamental crops, plug trays deliver a level of precision and efficiency that traditional nursery beds simply cannot match. Here’s a close look at why plug tray nursery raising has become the preferred choice in modern nursery management.

What is plug tray nursery raising? 🔗

A plug tray is a modular plastic container divided into individual cells, each acting as a mini growing unit for a single seedling or cutting. According to ATTRA – Sustainable Agriculture, a plug is essentially a containerized transplant with a self-enclosed root system. Cell counts per tray can range from as few as 12 to as many as 512, depending on the crop and the stage of production. Each cell is filled with a specially formulated soilless growing medium – typically a blend of cocopeat, vermiculite, and perlite – rather than garden soil. This combination of individual growing space and sterile media is the foundation of every benefit that plug tray systems offer.

Uniform seedling growth 🔗

One of the most significant advantages of plug tray systems is the consistency of seedlings they produce. In conventional open nursery beds, seedlings compete with each other for space, light, water, and nutrients. This competition creates variability – some plants grow faster, some slower, and the result is a batch of unevenly sized transplants that are difficult to manage in the field.

In a plug tray, each seedling has its own dedicated cell with an equal share of media, moisture, and nutrients. There is no competition. ATTRA reports that the advantages of plug-grown seedlings include more uniform growth and faster crop establishment. Research cited in the plug production literature has shown that plug nurseries can achieve close to 100% germination with vigorous, uniform seedlings, which directly improves the uniformity of the crop in the field and the quality of the final produce. Growers can realistically expect 95% or more of seedlings to reach transplantable quality – a figure that drops to 70-80% with traditional methods.

Suitability under adverse climatic conditions 🔗

Traditional outdoor nursery beds are highly vulnerable to weather extremes. Waterlogging, heat stress, or cold spells can wipe out large batches of seedlings with little warning. Plug tray systems, especially when used inside shade houses, net houses, or polyhouses, offer protection from these climate risks and allow year-round seedling production regardless of the season.

The individual cells in the tray also provide better insulation for root systems during hot spells and retain moisture more effectively during dry periods, reducing watering frequency. Research published in the International Journal for Multidisciplinary Research highlights that plug nursery production in protected conditions – even without full automation – allows seedling development in a controlled environment, reducing the time that fields remain occupied with the crop and improving scheduling flexibility for farmers.

Reduced soil-borne diseases and pest problems 🔗

One of the most compelling reasons to adopt plug tray nursery raising is the dramatic reduction in soil-borne diseases. Conventional nursery beds use field soil, which can harbour pathogens, nematodes, insects, and weed seeds. Damping-off, root rots, and viral diseases transmitted through the soil are common and costly problems in traditional nurseries.

Plug trays use sterilized soilless media that is completely free from these threats. The University of Georgia Extension strongly recommends against using field soil for containerized transplant production, noting that it drains poorly and is often contaminated with diseases and weed seed. According to the IJFMR paper on soilless plug nursery production, the inert media used in portrays is sterilized to ensure disease-free seedlings, and is completely free from weed seeds, soil-borne pathogens, and insects. The physical separation between cells also means that if a disease does appear in one seedling, it can be identified and removed before it spreads – something almost impossible to achieve in a traditional bed where root systems intertwine.

Minimizing transplant shock and seedling mortality 🔗

Transplant shock is a major cause of seedling loss in conventional nursery systems. When bare-rooted seedlings are pulled from an open bed, roots are torn, broken, and exposed to desiccation. The plant then has to spend energy recovering rather than establishing itself in the new site.

Plug-grown seedlings are removed from their cells with their root ball intact, enclosed within the growing media cone. A study published in Potato Research confirms that the plug system circumvents transplanting of bare-rooted seedlings, thereby reducing transplant shock. Guidelines from the plug nursery production literature recommend a 3-5 day hardening period before transplanting to further improve survival rates. Because the root system is undisturbed, plug-raised seedlings can begin accessing water and nutrients in their new environment almost immediately, resulting in faster establishment and visibly quicker re-growth after transplanting.

Quick establishment in the field 🔗

The intact root system is not just about survival – it is also about speed. ATTRA notes that plug-grown seedlings offer reduced root loss and faster crop establishment compared to traditional transplant production methods. Because the root-media plug stays cohesive during transplanting, the seedling experiences minimal stress and begins active growth much sooner. This is particularly valuable in commercial vegetable and flower production, where faster crop turnover directly improves profitability and allows more growing cycles per year.

Ideal for both sexual and asexual propagation 🔗

Plug trays are not limited to seed raising (sexual propagation). They are equally effective for vegetative (asexual) propagation methods such as stem cuttings, suckers, and even tissue culture-derived plantlets. OASIS® Fertiss® PlugTray, for example, is specifically designed for vegetative, seed, and tissue culture propagation of floriculture crops, vegetables, and soft fruits.

For cutting propagation, the individual cells provide ideal rooting conditions while preventing the spread of fungal infections that commonly affect cuttings placed in open rooting beds. Plug nursery documentation from India describes raising chrysanthemum, gerbera, rose, and anthurium through stem cuttings and suckers planted in plug cells filled with soilless cocopeat-based media. Once cuttings are treated with rooting hormones and placed in individual cells, the controlled microenvironment accelerates rooting while minimizing cross-contamination between plants.

Economy, ease of handling, and transportation 🔗

Plug trays offer significant economic advantages, though these become most visible over time. While there is an initial investment in trays and soilless media, the savings across the production cycle are substantial. The higher germination and survival rates mean fewer seeds are wasted – a critical factor when working with expensive hybrid varieties. The IJFMR study on soilless plug nurseries points out that every high-value hybrid seed is cared for individually in the protected nursery environment, making it possible to ensure nearly every seed becomes a healthy, transplantable seedling. Reduced reliance on pesticides and fungicides – made possible by the sterile growing conditions – also cuts recurring costs.

Plug trays are lightweight, stackable, and standardized in size, making them easy to move within a nursery. The Potato Research study notes that plug systems reduce the nursery area required and allow large quantities of seedlings to be produced efficiently for mechanized transplanting. When moving seedlings from nursery to field, the trays can be loaded directly onto a tractor or trolley, transported to the planting site, and individual plugs removed one by one without disrupting neighbouring plants. This reduces labour, minimises handling time, and ensures seedlings arrive at the field in good condition.

Supporting sustainable and modern nursery management 🔗

Beyond immediate production benefits, plug tray systems align well with the principles of sustainable agriculture. The reduced need for chemical inputs, the precise use of water and nutrients through fertigation in the protected nursery environment, and the potential to use biodegradable plug tray materials all contribute to a lower environmental footprint. UMass Extension’s vegetable management guidelines emphasize using soilless media that is free from insects, pathogens, nematodes, and weed seeds – all of which are standard features of a well-managed plug tray system. As hybrid seed use expands globally and labour costs rise, plug nursery systems offer an increasingly viable path to consistent quality at scale.

What do you think? If you manage or plan to establish a nursery, which of these advantages do you see as most critical for the crops in your region – disease prevention, transplant success, or production efficiency? And how do you think adopting plug tray nurseries could affect the economics of small-scale vegetable farming in your area?

References

1. https://attra.ncat.org/publication/plug-and-transplant-production-for-organic-systems/
2. https://www.ijfmr.com/papers/2024/3/16731.pdf
3. https://fieldreport.caes.uga.edu/publications/B1144/commercial-production-of-vegetable-transplants/
4. https://link.springer.com/article/10.1007/s11540-024-09799-w
5. https://www.slideshare.net/slideshow/publicationplug-nurserypdf/254472147
6. https://oasisgrowersolutions.com/collections/oasis%C2%AE-fertiss%C2%AE
7. https://nevegetable.org/vegetable-transplant-production/seeding-and-transplanting