Easy Guide to Seed Starting Trays: Pros, Cons, and Best Practices

Have you ever started seedlings, only to watch them struggle or fail? Seed starting can feel like an art form, but once you experience both wins and setbacks, you begin to understand what works best. Through trial and error, gardeners quickly learn that using seedling trays correctly can make all the difference in getting strong, healthy plants.

In this blog, you'll discover the pros and cons of using seedling trays versus direct sowing in raised garden beds, common myths, and pro tips from experienced gardeners who have mastered seed starting. From choosing the right seedling trays to best practices for watering, lighting, and transplanting, this guide will help you get the most out of your seedlings and achieve the best results for your garden.

1. Let’s Cover the Basics.

Seed starting trays, also known as cell trays, are designed to hold soil and seeds in individual compartments, providing an ideal environment for early growth. These trays come in various sizes and materials, including plastic trays, biodegradable pots, and peat pellets. A common setup consists of a base tray paired with plug trays or cell packs, which support seedlings until they’re ready for transplanting into larger containers or garden beds.

The type of plant you’re growing will determine the best seed tray size. Larger pots or trays work well for plants with deep root systems, while smaller cells are ideal for herbs and shallow-rooted vegetables. All this to say, choosing the right tray guarantees healthy root development and minimizes transplant shock when moving seedlings to their final growing space.

2. The Pros of Using Seed Starting Trays

Control Over Growing Environment

Seed starting trays provide greater control over germination conditions. For example, creating a humid environment is easy by using plastic trays with drainage holes, covered with a plastic dome or plastic bag to retain moisture. To prevent overheating, grow lights can be used strategically instead of relying solely on natural heat sources. This level of control is especially useful during seasonal transitions or extreme weather conditions, ensuring seedlings get the best start possible.

Improved Seed Germination

Seedling trays create an ideal environment for strong seed germination since their individual cells provide each seed with enough space to develop a healthy root system without competing for nutrients. They also retain moisture better than a flat tray of soil, ensuring seedlings receive consistent water. Plus, thinning extra seedlings is easier, preventing overcrowding and encouraging stronger growth.

Efficient Use of Space

For gardeners with limited space, seed trays offer a compact and organized way to start multiple plants at once. Whether placed on a windowsill, shelf, or under grow lights, they make the most of small indoor spaces. Growing multiple varieties in one tray also saves time and effort compared to using separate containers.

Easy Transplanting

Seedling trays simplify transplanting, as individual cells allow for gentle removal without damaging roots. This reduces transplant shock and helps seedlings adjust quickly to larger containers or the garden. Whether moving them to bigger pots or directly into garden beds, using seed trays ensures a smooth transition for healthy plants.

3. The Cons of Seed Starting Trays

Initial Investment

High-quality seed starting trays come with a price tag, and the cost can rise with the addition of grow lights, shelving, and heat mats. It's important to invest in durable trays that can be reused season after season. The Vego Garden seedling tray collection offers a variety of sizes and types to suit different budgets, plant sizes, and the number of trays needed.

Drainage Issues

Overwatering is a common concern with seed starting trays. Trays without proper drainage holes can lead to root rot from excess water, which can stunt seedling growth. It's crucial to invest in high-quality seed trays to prevent waterlogged soil and ensure healthy, thriving plants.

Plastic Waste

Although plastic trays are reusable, they do contribute to environmental waste over time. While they are often the best option for durability and repeated use, it's worth considering trays designed to last for many seasons. For those seeking more sustainable alternatives, biodegradable materials like peat or paper pots are great options. These trays break down in the soil, reducing plastic waste. However, they may need to be replaced each season, which might not be a practical option for all gardeners.

4. Best Practices for Using Seed Starting Trays

Choosing the Right Tray and Container Size

Selecting the right seed tray depends on the plant and cell size to prevent crowding and allow roots to develop properly. Small seeds like lettuce or herbs thrive in smaller cells, while larger seeds such as beans or tomatoes require larger cells or peat pots.

Use a High-Quality Potting Mix

Garden soil is often too heavy and compact for seedlings, hindering growth. Opt for a loose, well-draining seed starting mix to ensure strong growth and healthy development.

Provide the Right Light

Seedlings need adequate light for healthy growth, whether from natural or artificial sources. A south-facing window is ideal, but if natural light is limited, grow lights or fluorescent lights are essential. 

Watering and Moisture Management

Overwatering can stunt seedling growth, so it's important to choose seed trays with a good drainage system. Water carefully, keeping the soil moist but not soaking wet.

Hardening Off Your Seedlings

Don’t skip the hardening-off process, as it’s crucial for success. Gradually expose seedlings to outdoor conditions by placing them outside in a warm spot for a few hours each day. This helps them adjust to wind, temperature, and sunlight, reducing transplant shock when moved to garden beds.

 

Final Thoughts

Seed starting trays are a fantastic tool for home gardeners, as they provide a controlled environment for growing healthy seedlings for a wide variety of plants. However, their success largely depends on how well they’re set up. By following best practices—such as choosing the right tray, providing adequate light, and ensuring good drainage—you’ll give your plants the best start for a successful growing season.