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If you want to start your own plants from seeds indoors, you will need good seed-starting trays to make the process easier and more successful. Seed-starting trays are containers with multiple cells where you can sow seeds and grow seedlings until they are ready to be transplanted into your garden or larger pots.

Our top pick for the best seed starting trays are:

Gardzen 5-Set Garden Propagator Set

This set comes with five trays of 40 cells each, giving you plenty of space to start 200 seedlings. Each tray has a base tray to catch water from the drainage holes and a dome to help regulate humidity. The seedling trays are made of sturdy and BPA-free plastic that is safe for vegetables and flowers. The cells are 1.4 x 1.4 inches and 1.85 inches deep, which are suitable for most types of seeds.

Some of the other seed starting trays we recommend are:

Industry Standard Grower’s Supply 720-Cell Seedling Starter Trays:

These are the best seed-starter trays for budget-conscious gardeners who want to start a lot of seeds. They come with 120 trays of six cells each that are small enough to fit on a windowsill or under a grow light. The cells are 1.5 x 1.5 inches and 2.25 inches deep, which is ideal for most seeds. However, these trays do not come with any accessories, so you will need to buy them separately if you need them.

Park Seed Bio Dome Seed Starter Kit:

This is the best seed starter tray for splurging gardeners who want a mini greenhouse kit with extra features. It comes with one tray of 40 cells that have more space between them to allow plants to grow uniformly. It also comes with bio sponges that improve germination rates and root growth. The clear dome has adjustable vents to control humidity and air circulation. The kit also includes a base watering tray, a packet of seedling food, and a planting diagram.

Sili-Seedlings Seed Starter Trays:

This is the best seed starter tray for eco-friendly gardeners who want a reusable silicone option. It comes with two trays of six cells each that are dishwasher-safe and easy to clean. The silicone is flexible and BPA-free, making it easy to pop out the seedlings without damaging the roots. The cells are 2 x 2 inches and 2 inches deep, which is generous enough for most seeds. The tray also comes with a watering tray and a planting diagram.

2NLF Seed Starter Tray:

This is the best seed starter tray for biodegradable gardeners who want to plant their seedlings directly into the ground. It comes with 12 trays of 10 cells each that are made of paper and peat moss that will decompose in the soil over time. This helps reduce transplant shock and provides fertilizer to the plants. The cells are 1.95 x 1.95 inches and 2 inches deep, which is good enough for most seeds. The tray also comes with plant labels, a dibber, and a widger.

Burpee Self-Watering Seed Starter Kit:

This is the best seed starting tray for beginner gardeners who want an easy-to-use kit with everything they need. It comes with two trays of 36 cells each that have a self-watering mat that draws water from the base tray. This helps prevent overwatering and under-watering the seedlings. It also comes with pellets of coconut coir that expand when watered and hold the optimal amount of moisture. The kit also includes two plant stands, a dome, a planting diagram, and a tool to mix the soil.

To use seed starting trays effectively, you need to consider several factors, such as cell size, depth, humidity, and soil moisture. Here are some tips from our experts:

Cell size: The size of the cells in your seed starting tray will affect how long you can keep your seedlings in the tray before transplanting them. “Generally, the larger the number of cells on a tray, the smaller the size of each cell,” Tan says. “Small cells will often need to be transplanted into larger pots or trays, while some large-celled plugs can produce plants strong enough to be sown directly into the soil in the garden.”

Depth: The depth of the cells in your seed starting tray will affect how well your seedlings develop their roots. “On average, aim for 2-inch-deep pots,” Miller suggests. “But some plants may need deeper or shallower cells depending on their root system.”

Humidity: The humidity level in your seed starting tray will affect how well your seeds germinate and grow. “Soil moisture is crucial for seed germination, so a humidity cover/dome is important at the very beginning,” Miller says. “Just remove it once seedlings have sprouted.” You can also use domes with vents to adjust the humidity and air circulation as needed.

Soil moisture: The soil moisture in your seed starting tray will affect how healthy your seedlings are. You can use drainage holes, base trays, or self-watering mats to help you water your seedlings properly. “You want to keep the soil moist but not soggy,” Tan says. “You can also water from the bottom to avoid splashing water on the leaves and stems, which can cause diseases.”

Starting seeds indoors is a great way to get a head start on your gardening season and grow a wider variety of plants. With the best seed starting trays and some expert tips, you can enjoy growing healthy and strong plants for your garden.