Understanding Seed Tray: Technical Specifications, Grades, and Application Techniques

Types of Seed Trays: A Comprehensive Guide

A seed tray is an essential gardening tool designed to provide an optimal environment for seed germination and early seedling development. These containers feature multiple small compartments—called cells—that allow each seed to grow independently, preventing root competition and overcrowding. Seed trays come in various materials, sizes, and designs, each offering unique benefits and trade-offs in durability, moisture control, environmental impact, and plant health. Choosing the right type of seed tray can significantly influence your gardening success, whether you're starting herbs on a windowsill or managing a commercial nursery.

Plastic Seed Trays

Durable, lightweight trays made from rigid polypropylene or polystyrene, ideal for both indoor and outdoor seed starting.

Advantages

• Lightweight and easy to handle and transport
• Reusable and long-lasting with proper care
• Available in various cell sizes (mini for herbs, large for tomatoes/peppers)
• Drainage holes prevent root rot by managing excess water
• Affordable and widely available at garden centers

Limitations

• Can become brittle and crack when exposed to prolonged UV sunlight
• Less eco-friendly; contributes to plastic waste if not reused
• May harbor pathogens if not cleaned properly between uses

Best for: Home gardeners, beginners, indoor seed starting, and seasonal outdoor use with shade protection

Metal Seed Trays

Heavy-duty trays crafted from aluminum or stainless steel, built for durability and commercial applications.

Advantages

• Extremely durable and resistant to physical damage
• Ideal for high-traffic or commercial growing environments
• Easy to sanitize and reuse across growing cycles
• Recyclable and more sustainable than plastic in the long term
• Resistant to warping and cracking under stress

Limitations

• Prone to rust if made from non-stainless metals or left in damp conditions
• Higher initial cost compared to plastic or wood
• Heavier, making them harder to move when filled
• Poor insulation—can get too hot or cold for delicate roots

Best for: Commercial nurseries, professional growers, and gardeners needing rugged, long-term solutions

Clay Seed Trays

Traditional, porous trays made from fired natural clay, offering excellent aeration and a classic aesthetic.

Advantages

• Superior air circulation promotes healthy root development
• Natural material with minimal environmental impact
• Heavyweight design provides stability and reduces tipping
• Attractive appearance enhances patios, greenhouses, and garden displays
• Breathable walls help prevent overwatering issues

Limitations

• Dries out quickly due to high porosity, requiring frequent watering
• Fragile—can crack or break if dropped or exposed to freezing temperatures
• More expensive than plastic alternatives
• Heavier, making them less portable

Best for: Ornamental gardening, succulents, well-drained plants, and decorative indoor displays

Wooden Seed Trays

Crafted from sustainable wood, these trays offer natural insulation and eco-friendly appeal.

Advantages

• Made from renewable, biodegradable materials
• Excellent natural insulation—keeps roots warm in cooler climates
• Durable when treated or made from rot-resistant wood (e.g., cedar)
• Biodegradable options available for single-use or no-transplant systems
• Aesthetically pleasing with a rustic, organic look

Limitations

• Can warp, rot, or degrade if exposed to constant moisture
• Harder to clean and sanitize between uses
• May require sealing or treatment to extend lifespan
• Less commonly available in standardized cell sizes

Best for: Organic gardening, cold-climate seed starting, and eco-conscious growers

Rock Wool Seed Trays

Soilless growing systems made from spun basalt rock, commonly used in hydroponics and controlled environments.

Advantages

• Exceptional water retention and air porosity for strong root growth
• Sterile medium reduces risk of soil-borne diseases
• Ideal for hydroponic and aquaponic systems
• Reusable with proper cleaning and pH balancing
• Precise nutrient control for optimal plant development

Limitations

• High initial cost compared to other materials
• Not biodegradable—poses environmental disposal challenges
• Requires pre-soaking and pH adjustment before use
• Not suitable for traditional soil gardening

Best for: Hydroponic growers, commercial operations, and advanced gardeners seeking precision control

Type	Durability	Moisture Control	Eco-Friendliness	Best For
Plastic	Good	Good (with drainage)	Fair (reusable but not biodegradable)	Beginners, home gardeners, general use
Metal	Excellent	Fair (can overheat)	Good (recyclable)	Commercial growers, heavy-duty use
Clay	Fair	Poor (dries quickly)	Excellent (natural, biodegradable)	Ornamental plants, decorative use
Wooden	Good (if treated)	Good (moderate retention)	Excellent (renewable, compostable)	Organic gardening, cold climates
Rock Wool	Good (reusable)	Excellent (balanced air/water)	Poor (non-biodegradable)	Hydroponics, controlled environments

Expert Tip: For plastic and metal trays, clean thoroughly with a 10% bleach solution between uses to prevent disease transfer. For rock wool, always pre-soak and adjust pH to 5.5–6.5 before planting seeds to ensure optimal germination.

Design of Seed Trays: Optimizing Early Plant Growth

The design of seed trays plays a crucial role in creating an ideal environment for seedling development. Thoughtfully engineered to support healthy root formation, moisture retention, and efficient space utilization, modern seed trays are essential tools in both home gardening and commercial horticulture. Each tray type is designed with specific plant needs and growing conditions in mind, ensuring optimal germination and early growth.

Types of Seed Trays and Their Benefits

Modular Trays

Modular seed trays feature multiple individual cells, each acting as a self-contained mini-pot for a single seedling. This compartmentalized design prevents root entanglement between plants, minimizing transplant shock when moving seedlings to larger containers or outdoor beds.

These trays are highly efficient for greenhouse and nursery operations, allowing for uniform spacing, easy labeling, and stackable storage. Their standardized size also makes them compatible with automated seeding and irrigation systems, improving workflow efficiency.

Cell Trays

Similar to modular trays, cell trays are distinguished by deeper individual compartments that provide enhanced vertical root development. This extra depth is especially beneficial for plants with taproots or extensive root systems, such as carrots, sunflowers, or certain herbs.

Available in a variety of cell sizes—from 32-cell to 200-cell configurations—these trays allow growers to customize density based on plant species and growth duration. Some models include tapered walls and air-pruning features to encourage fibrous root branching and prevent circling.

Flat Trays

Flat seed trays offer a continuous, open surface without internal divisions, making them ideal for broadcasting small seeds like lettuce, greens, or wildflowers. This design allows for dense sowing and is commonly used for microgreens, grass plugs, or ground cover propagation.

While they require thinning during growth, flat trays maximize space usage and are often used in conjunction with misting systems for even moisture distribution. They can also serve as bottom trays to catch excess water from potted seedlings.

Insert Trays

Insert trays consist of a durable base tray with removable cell inserts. This modular system allows gardeners to swap different cell configurations—such as 48-cell for vegetables or 72-cell for flowers—without purchasing multiple full trays.

The flexibility supports crop rotation and sanitation, as inserts can be easily cleaned, sterilized, or replaced. This design is popular in commercial nurseries and research facilities where precision and hygiene are critical.

Deep Trays

Deep seed trays provide significantly more vertical space than standard models, typically ranging from 3 to 6 inches in depth. This additional room supports longer root development, reducing the need for early transplanting.

Ideal for slow-growing or deep-rooted crops like tomatoes, peppers, eggplants, and brassicas, these trays help produce stronger, more resilient seedlings. The extended growing period in one container minimizes stress and labor associated with frequent repotting.

Specialized Trays

Specialized seed trays are tailored for specific growing methods or plant types. Examples include hydroponic propagation trays with net pots, plug trays for soilless media, and peat-based block molds that eliminate plastic use.

Other variants include self-watering trays with capillary mats, humidity domes for moisture control, and biodegradable trays made from coconut coir or recycled paper. These innovations support sustainable practices and advanced cultivation techniques.

Ergonomic Trays

Ergonomic seed trays are designed with user comfort and efficiency in mind. Features such as integrated handles, lightweight materials, and ribbed edges make them easier to carry, stack, and maneuver—especially during large-scale planting operations.

Some models include anti-slip surfaces and optimized dimensions to reduce wrist strain and improve accessibility for gardeners with mobility concerns. These thoughtful designs enhance productivity and reduce physical fatigue in commercial greenhouses and home gardens alike.

Material & Sustainability

Seed trays are commonly made from recycled polypropylene or polystyrene due to their durability and moisture resistance. However, eco-friendly alternatives like biodegradable pulp, bamboo fiber, and compostable plant-based plastics are gaining popularity.

Reusable trays reduce environmental impact and long-term costs, while disposable options offer convenience and disease prevention through single-use cycles. Choosing the right material depends on growing scale, budget, and sustainability goals.

Tray Type	Best For	Root Development	Reusability
Modular Trays	Vegetables, flowers, herbs	Controlled, non-entangled	High (durable plastic)
Cell Trays	Tap-rooted plants, transplants	Deep, structured	High
Flat Trays	Microgreens, broadcasting	Shallow, spreading	Moderate to High
Insert Trays	Variable crops, nurseries	Customizable	Very High (modular)
Deep Trays	Tomatoes, peppers, brassicas	Extended, robust	High
Specialized Trays	Hydroponics, plugs, organics	Method-specific	Variable
Ergonomic Trays	All-day planting, accessibility	Standard to Deep	High

Key Selection Tips for Growers

Match Tray to Plant Type: Choose deeper trays for long-season crops and smaller cells for fast-growing greens.

Consider Reusability: Invest in durable trays for long-term use; opt for biodegradable options for direct planting.

Ensure Drainage: Look for trays with adequate drainage holes to prevent waterlogging and root rot.

Optimize Space: Use modular or insert trays to maximize greenhouse or indoor growing area.

Promote Air Pruning: Select trays with vented walls to encourage healthy root branching and prevent circling.

Important: Always clean and disinfect reusable trays between growing cycles to prevent the spread of fungal diseases and pests. Using dirty trays can compromise an entire crop. Additionally, avoid overfilling trays with soil—leave about 1/4 inch at the top for watering. Proper tray selection and care significantly improve germination rates and seedling vigor.

Scenarios of Seed Trays: Versatile Tools for Modern Gardening and Agriculture

Seed trays are essential tools in modern horticulture, offering a controlled and efficient environment for seed germination and early plant development. Their versatility extends far beyond simple seed starting, playing critical roles across commercial, scientific, educational, and ecological applications. By providing uniform growing conditions, ease of handling, and scalability, seed trays have become indispensable in diverse agricultural and environmental practices.

Commercial Horticulture

Large-scale nurseries and agricultural operations rely heavily on seed trays to streamline the production of healthy, uniform seedlings. These businesses use standardized trays to ensure consistency in spacing, watering, and nutrient delivery, which is vital for efficient mass propagation.

• Commercial growers often use modular trays with 72 to 200 cells, allowing for high-density planting and optimized space usage in greenhouses
• The trays are compatible with automated seeding, irrigation, and transplanting systems, reducing labor costs and increasing operational efficiency
• Stackable and interlocking designs enable vertical farming techniques and maximize space in controlled environments
• Trays are often made from durable, reusable plastics or biodegradable materials to support sustainable practices

Key benefit: Uniform growth conditions lead to synchronized development, making harvesting and transplanting more predictable and efficient.

Research and Plant Breeding

In scientific settings, seed trays are fundamental for conducting controlled experiments in plant genetics, physiology, and pathology. Their standardized format allows researchers to maintain consistent variables such as soil volume, moisture, and light exposure.

• Scientists use seed trays to test hybridization outcomes, evaluate disease resistance, and study plant responses to stress factors like drought or salinity
• Individual cell compartments prevent root entanglement, enabling precise monitoring of each plant’s development
• Trays are used in growth chambers and labs to replicate environmental conditions for repeatable trials
• Barcode-labeled trays help track genetic lines and experimental data across multiple generations

Scientific advantage: Controlled environments enhance data accuracy and reproducibility in plant breeding programs.

Aquaponics and Hydroponics Systems

Seed trays are integral to soilless cultivation methods such as hydroponics and aquaponics. They serve as the starting point for seedlings before transfer to nutrient-rich water systems or fish-integrated grow beds.

• Net pots or foam inserts fit into seed tray cells, holding rockwool, coco coir, or clay pebbles as growing media
• Once roots develop, seedlings are easily transplanted into deep water culture (DWC), nutrient film technique (NFT), or aquaponic tanks
• Trays with drainage holes prevent waterlogging and promote healthy root aeration during early growth
• Lightweight, UV-resistant trays are ideal for indoor vertical farms and rooftop gardens using hydroponic setups

Innovation note: Seed trays enable seamless integration between germination and automated hydroponic systems, supporting year-round crop production.

Restoration Projects and Conservation

Ecological restoration initiatives use seed trays to propagate endangered, native, or region-specific plant species in controlled settings before reintroducing them into degraded ecosystems.

• Conservationists grow rare wildflowers, grasses, and trees in seed trays to protect them from pests, invasive species, and harsh weather during early stages
• Biodegradable trays made from peat, rice hulls, or paper can be planted directly into the ground, minimizing transplant shock
• Projects focused on reforestation, wetland recovery, or pollinator habitat restoration depend on trays to produce thousands of seedlings annually
• Trays allow for careful monitoring of germination rates and early survival, improving the success of reintroduction efforts

Environmental impact: Seed trays support biodiversity by enabling large-scale propagation of native flora for habitat rehabilitation.

Education and Training

Seed trays are widely used in educational institutions to teach students about plant life cycles, sustainable agriculture, and environmental stewardship through hands-on learning.

• Schools and universities use seed trays in biology labs and horticulture courses to demonstrate germination, photosynthesis, and nutrient uptake
• Extension programs and community gardens provide trays for workshops on urban farming, composting, and organic gardening
• Students learn practical skills such as proper watering, thinning, labeling, and pest identification using real-world tools
• Classroom projects with seed trays foster responsibility, observation skills, and an appreciation for nature

Teaching value: Seed trays transform abstract concepts into tangible experiences, making science and agriculture accessible to learners of all ages.

Expert Insight: When selecting seed trays for any application, consider factors such as cell size (larger cells for deep-rooted plants), material (reusable plastic vs. compostable options), drainage capacity, and compatibility with existing systems. For best results, pair trays with humidity domes during germination and use bottom watering techniques to encourage strong root development.

Application	Common Tray Type	Typical Growing Medium	Key Advantages
Commercial Horticulture	Plastic modular trays (72–200 cells)	Potting mix, peat-based media	High efficiency, automation compatibility, uniform growth
Research & Breeding	Standardized cell trays with labels	Sterile soilless mixes	Precise control, data tracking, contamination prevention
Hydroponics/Aquaponics	Net pot inserts in trays	Rockwool, coco coir, clay pebbles	Easy transplanting, root aeration, system integration
Conservation & Restoration	Biodegradable or deep-cell trays	Natural soil blends, native substrates	Reduced transplant shock, eco-friendly, species-specific
Education & Outreach	Clear trays with domes	Universal potting soil	Visible root growth, durability, beginner-friendly

Additional Considerations

• Sustainability: Reusable trays reduce plastic waste, while biodegradable options support eco-conscious gardening practices
• Drainage Design: Proper hole placement prevents waterlogging and promotes healthy root systems
• Lightweight & Stackable: Facilitates storage, transport, and space optimization in greenhouses or classrooms
• Compatibility: Many trays are designed to work with automated systems, irrigation mats, and heating pads
• Hygiene: Smooth surfaces allow for easy cleaning and disinfection, reducing disease transmission between growing cycles

How to Choose Seed Trays: A Comprehensive Guide for Wholesale Buyers

Selecting the right seed trays is essential for supporting healthy seedling development and meeting customer expectations. Whether supplying home gardeners, commercial nurseries, or urban farming operations, wholesale buyers must evaluate several critical factors. The ideal seed tray balances durability, functionality, sustainability, and ease of use. This guide provides a detailed breakdown of the key considerations to help you make informed purchasing decisions that deliver value to your customers and promote successful plant growth.

Important Note: Seed trays are not one-size-fits-all. Different crops, growing environments, and cultivation methods require specific tray designs. Always consider your end-user’s growing practices when selecting trays.

Key Factors in Seed Tray Selection

• Materials and Durability

  The material of a seed tray significantly impacts its lifespan, performance, and environmental footprint. Each material offers distinct advantages:

  • Plastic trays are the most common choice due to their durability, affordability, and reusability. High-density polyethylene (HDPE) or polystyrene trays can last 5–10 growing seasons with proper care, making them cost-effective for commercial operations.
  • Biodegradable trays, made from materials like peat, coir, rice hulls, or compressed paper, are ideal for eco-conscious customers. These break down naturally in the soil, reducing transplant shock and eliminating plastic waste.
  • Metal trays (typically galvanized steel) offer exceptional durability and are often used as bottom flats or propagation trays in greenhouses. They resist warping and are easy to sanitize between uses.
  • Wooden trays provide excellent thermal insulation, helping to regulate root zone temperature. Cedar or redwood trays are naturally rot-resistant and add an aesthetic appeal, though they are heavier and more expensive.
• Cell Size and Depth

  Cell dimensions directly influence root development and transplant success. Choosing the right size ensures seedlings have adequate space to grow without becoming root-bound:

  • Small cells (1–2 inches) are perfect for fine-seeded crops like lettuce, broccoli, carrots, and herbs. They maximize space efficiency in propagation areas.
  • Medium cells (3–4 inches) suit most common vegetables and flowers such as peppers, marigolds, and zinnias. This size provides a balance between root space and tray capacity.
  • Large cells (5+ inches) are ideal for deep-rooted or fast-growing plants like tomatoes, cucumbers, squash, and ornamental shrubs. These reduce the need for transplanting and support stronger root systems.
  • Depth matters: Aim for a minimum depth of 2.5–3 inches to allow proper root elongation. Deeper cells (4+ inches) are beneficial for crops with taproots or extended indoor growing periods.
• Drainage and Bottom Flat Compatibility

  Effective water management is crucial for preventing disease and promoting healthy growth:

  • Look for trays with multiple drainage holes in each cell to prevent waterlogging and encourage air pruning of roots, which leads to healthier, fibrous root systems.
  • Pair seed trays with bottom flats or saucers to catch excess water and protect surfaces. These are especially useful in indoor or greenhouse settings.
  • Consider self-watering or capillary mats systems for consistent moisture delivery. These wick water from a reservoir into the growing medium, reducing labor and minimizing overwatering risks.
  • Trays with built-in feeder channels or wicking strips enhance water distribution and are ideal for automated growing setups.
• Seed Starting Method Compatibility

  Modern gardening uses diverse seed-starting techniques—your trays should support these methods:

  • Soil blocking: While not a tray system, some growers use trays to hold soil blocks. Choose shallow, open-top trays without cells for this purpose.
  • Heated propagation mats: Ensure trays are heat-resistant and have flat bottoms for optimal contact with heating elements. Plastic and metal trays work best.
  • Hydroponic or soilless systems: Use trays compatible with rockwool cubes, peat pellets, or net pots. Look for inserts or modular designs that hold these media securely.
  • Automation readiness: For large-scale operations, select trays that are uniform in size and shape to work with automated seeding, watering, and transplanting equipment.
• Ease of Use and Handling

  Efficiency and ergonomics are vital for both commercial growers and home users:

  • Trays with integrated handles make transport easier, especially when filled with soil and seedlings.
  • Stackable and nestable designs save significant storage space and reduce shipping costs. Nested trays can occupy up to 70% less volume when empty.
  • Look for reinforced rims and corners to prevent warping and cracking during handling.
  • Lightweight yet sturdy trays reduce labor fatigue and are easier to ship and distribute.
  • Uniform tray dimensions (e.g., 10" x 20") ensure compatibility with standard greenhouse benches, shelving, and lighting systems.
• Sustainability and Reusability

  Environmental responsibility is increasingly important to consumers and retailers alike:

  • Prioritize trays made from recycled plastics or those that are themselves recyclable at end-of-life.
  • Reusable plastic trays reduce long-term waste and offer a lower cost per use over time. Encourage customers to sanitize and reuse them annually.
  • Biodegradable trays should be certified compostable (e.g., BPI-certified) to ensure they break down safely without microplastics.
  • Consider the carbon footprint of production and shipping—locally manufactured or lightweight trays can reduce environmental impact.
  • Offer a range of sustainable options to meet diverse customer values, from budget-friendly recycled plastic to premium compostable trays.

Material Type	Lifespan	Eco-Friendliness	Best For	Cost Efficiency
Plastic (HDPE)	5–10 years	Moderate (if reused)	Commercial growers, frequent users	★★★★☆
Biodegradable (Peat/Coir)	Single season	High	Eco-conscious gardeners, direct planting	★★★☆☆
Metal (Galvanized)	10+ years	High (recyclable)	Greenhouse flats, heavy-duty use	★★★★☆
Wood	3–5 years	High (natural)	Organic growers, aesthetic appeal	★★☆☆☆
Recycled Plastic	5+ years	High (closed-loop)	Sustainable operations, green retailers	★★★★☆

Pro Tip: Offer tiered product lines—budget, standard, and premium—to cater to different customer segments. Bundle trays with complementary products like humidity domes, labels, or seed starting kits to increase value and convenience.

Final Recommendations for Wholesale Buyers

• Stock a variety of cell sizes to accommodate different crop types and growing preferences.
• Partner with suppliers who provide product testing data or grower testimonials.
• Train your sales team on the benefits of each tray type to better assist customers.
• Consider offering sample packs so customers can test different trays before bulk purchasing.
• Monitor return rates and customer feedback to refine your inventory over time.
• Promote trays with features that reduce labor and increase success rates—these add measurable value.

Choosing the right seed trays goes beyond basic functionality—it’s about supporting successful plant starts, reducing environmental impact, and delivering solutions that meet the evolving needs of modern gardeners. By focusing on material quality, design efficiency, and sustainability, wholesale buyers can build trust, increase customer satisfaction, and stand out in a competitive market.

Frequently Asked Questions About Seed Trays and Seedling Care

Q1: How deep should seed trays be for optimal seedling growth?

Seed trays should be at least 2–3 inches (5–7.5 cm) deep to support healthy root development. This depth provides sufficient space for young roots to grow downward without becoming root-bound or stunted.

• Shallow trays (less than 2 inches): May restrict root growth, leading to early transplanting needs or reduced plant vigor.
• Deeper trays (3+ inches): Ideal for larger seedlings or slow-growing plants like peppers and tomatoes, allowing extended time before transplanting.
• Cell trays vs. flat trays: Modular cell trays help isolate root systems and reduce transplant shock, while flat trays are better for thinning and pricking out seedlings later.

Choosing the right depth ensures your seedlings develop a strong root foundation before moving to their final growing location.

Q2: How long can seedlings stay in seed trays before needing to be transplanted?

Most seedlings can remain in seed trays for 3 to 6 weeks, depending on the plant species and growing conditions. The key is to transplant them before they become leggy, overcrowded, or root-bound.

• Fast-growing seedlings (e.g., lettuce, radishes): May need transplanting within 3–4 weeks.
• Slow-growing seedlings (e.g., peppers, herbs): Can stay in trays for up to 6 weeks with proper care.
• Signs it’s time to transplant: Yellowing leaves, roots emerging from drainage holes, elongated stems (legginess), or visible competition between seedlings.

Transplanting at the right time promotes stronger growth and reduces stress on young plants as they transition to larger pots or outdoor beds.

Q3: Should seed trays be covered during germination?

Yes, covering seed trays with a clear plastic dome or wrap helps maintain consistent moisture and humidity levels—critical for successful germination. The cover acts like a mini greenhouse, trapping warmth and reducing evaporation.

• When to cover: From sowing until the first seedlings emerge (usually 3–10 days, depending on the plant).
• When to remove: As soon as sprouts appear, remove the cover to prevent mold, mildew, and damping-off disease caused by excess moisture and poor air circulation.
• Alternative options: Use humidity domes with vents to gradually acclimate seedlings, or mist lightly instead of overwatering.

Proper use of covers improves germination rates and gives your seeds the best start possible.

Q4: How often should seedlings be watered in seed trays?

Seedlings typically need watering once daily or every other day, depending on temperature, humidity, and tray size. The goal is to keep the top inch of soil consistently moist but not waterlogged.

• Check soil moisture: Gently press your finger into the soil—water when the surface feels dry.
• Watering method: Use a spray bottle for delicate sprouts or a watering can with a fine rose nozzle to avoid disturbing the soil.
• Bottom watering: Highly recommended—place trays in a shallow water bath so soil absorbs moisture from below, encouraging deeper root growth and reducing fungal risks.

Overwatering is a common mistake; ensure trays drain properly and never leave seedlings sitting in standing water for extended periods.

Q5: Do seed trays need drainage holes to grow healthy seedlings?

Yes, drainage holes are essential in seed trays to prevent overwatering, root rot, and fungal diseases like damping-off. They allow excess water to escape, maintaining a balanced moisture level in the soil.

• No holes = waterlogged soil: Saturated soil deprives roots of oxygen, leading to weak, rotting roots and poor seedling development.
• Even moisture distribution: Holes help ensure water doesn’t pool at the bottom, promoting uniform root growth.
• Best practice: Use trays with multiple small drainage holes and pair them with saucers to catch runoff—this gives you control over watering while protecting surfaces.

If using trays without holes, drill a few evenly spaced holes or switch to a proper seed-starting tray to ensure long-term success.