What Is the Best Seed Starter Trays: Top Picks and Buying Guide
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Choosing among seed starter trays can be surprisingly difficult when the listings mix cell counts, humidity domes, bases, and very different tray sizes. A beginner may need a compact kit for a few herbs, while another gardener may need hundreds of small cells or a flat suitable for microgreens.
My first choice is MIXC 5 Pack Seed Starter Tray. Its five complete tray-and-dome sets offer useful capacity without requiring a large single planting flat, and the adjustable vents make humidity management more practical for indoor or outdoor starting.
My second choice is Amazon.com Mr. Pen- Seed Starter Tray Kits 10 Pack Total. It is the option I would compare next when a buyer has slightly different priorities from my first pick.
This comparison explains what each kit is designed to do, where its limitations matter, and which type of gardener is most likely to appreciate it. The buying guidance also covers cell size, drainage, humidity control, transplanting, cleaning, storage, and common setup mistakes.
5 Best Seed Starter Trays
I selected these products by comparing their stated relevance to seed starting, practical details such as cell layout and drainage, customer-feedback evidence when available, and useful brand variety where a different design solved a real gardening need. The ranking favors complete, clearly described setups while also including a large flat for hydroponic growing and microgreens.
| # | Image | Product | Price on Amazon |
|---|---|---|---|
| 1 |  |
MIXC 5 Pack Seed Starter Tray | Check Price |
| 2 |  |
Amazon.com Mr. Pen- Seed Starter Tray Kits 10 Pack Total | Check Price |
| 3 |  |
Amazon.com Mr. Pen- Seed Starter Tray Kits 6.6 X4.6 10 | Check Price |
| 4 |  |
GREENBAZZAR Seed Starter Tray | Check Price |
| 5 |  |
Living Whole Foods 10 Plant Growing Trays | Check Price |
MIXC 5 Pack Seed Starter Tray
The MIXC kit earns the top position because it balances capacity, modularity, and control. Five seed trays, five bottom trays, and five clear humidity domes can be used as separate growing units, which is more flexible than relying on one oversized flat. The transparent plastic also lets you observe seedlings without lifting the cover repeatedly.
Each cell measures 1.5 by 1.5 inches and is 2 inches deep, so this setup is aimed at small seeds and early-stage seedlings rather than plants that need a large root zone. The 2.75-inch dome height provides a compact greenhouse space, while adjustable vents let you release excess humidity or retain more moisture during germination. That adjustability is particularly useful because different seeds do not all need identical conditions.
Space-conscious gardeners may appreciate that the bottom trays can be stacked before germination. The kit also includes two garden tools and 10 plant labels, giving a beginner a practical starting point without adding separate accessories immediately. Still, the compact cells mean you should plan to transplant seedlings as they develop instead of leaving vigorous plants in place indefinitely.
Pros
- Five separate tray, base, and dome sets provide flexible capacity.
- Adjustable vents help manage humidity and temperature.
- Clear plastic makes growth easy to monitor.
- Stackable bottom trays help conserve storage space.
- Labels and two garden tools are included.
Cons
- Small cells are not intended for large or long-term seedlings.
- The compact dome height limits room for taller growth.
- Buyers need to check the listed dimensions before ordering.
My Opinion
This is the strongest all-around choice for beginners who want several manageable propagation units rather than one giant tray. Its adjustable vents and complete accessories add practical value, but gardeners growing larger transplants should be ready to pot up promptly.
Amazon.com Mr. Pen- Seed Starter Tray Kits 10 Pack Total
The 10-pack Mr. Pen kit is the capacity choice in this group. It includes 10 40-cell trays, 10 matching bases, and 10 transparent domes, for a total of 400 cells. That arrangement makes sense for gardeners starting many varieties at once, as well as classrooms or greenhouse projects where a few trays would be used up quickly.
The vented domes help retain warmth and moisture while still offering a way to provide ventilation. Clear covers make it easier to watch germination without disturbing the growing medium, and the matching bases give each tray a designated place to collect or support water. Because the cells are divided into 40 compartments per tray, this kit favors quantity and organization over generous space for each plant.
A dibber and widger are included along with a shovel and scoop. Those tools can make sowing at a consistent depth and removing seedlings more manageable, especially for someone assembling a first indoor growing station. The main ownership consideration is scale: 10 trays require considerable shelf, windowsill, or greenhouse space once they are filled, even though the individual cells keep varieties separated.
Pros
- Ten complete trays provide 400 total cells.
- Matching bases and vented domes are included.
- Clear covers support easy growth monitoring.
- Included tools help with sowing and transplanting.
- Well suited to classrooms, greenhouses, and large planting plans.
Cons
- Forty-cell trays prioritize volume over larger root space.
- The full 10-pack can require substantial growing and storage room.
- The supplied data does not specify individual cell dimensions.
My Opinion
Choose this kit when the central problem is producing a large number of seedlings. It is less appealing for a small apartment gardener who only needs a few herbs, but its complete 10-tray format is a strong alternative to the more compact MIXC arrangement.
Amazon.com Mr. Pen- Seed Starter Tray Kits 6.6 X4.6 10
This smaller Mr. Pen kit takes a more compact approach, supplying 10 sets with 12 cells each for 120 total cells. The stated 6.6-by-4.6-inch tray size is easier to fit into a limited indoor growing area than a larger propagation flat, making it a practical option for gardeners who want multiple varieties without committing to 400 starts.
Each tray includes a transparent dome with adjustable vents. That combination supports moisture retention while giving the grower a way to introduce ventilation as seedlings emerge. Drainage holes at the base of each cell are also important because they allow excess water to leave the root area, reducing the risk of keeping the growing medium constantly saturated.
The design is intended to help seedlings release with minimal root disturbance. That can be useful when moving young plants into larger containers or outdoor beds, although careful handling is still necessary because small seedlings are naturally delicate. A shovel and scoop round out the kit, while the 12-cell layout gives better variety separation than a single large tray.
This model may be the better Mr. Pen choice for a modest garden, particularly when the buyer wants 10 separate growing units. The trade-off is that each unit holds fewer plants, so it will not match the 400-cell version for bulk production.
Pros
- Ten compact sets offer 120 cells in total.
- Adjustable vents support changing humidity needs.
- Drain holes help prevent excess water around roots.
- The cell design is intended to ease seedling removal.
- Included shovel and scoop support planting and transplanting.
Cons
- Its 120-cell capacity is lower than the other Mr. Pen kit.
- Small individual units may be less efficient for high-volume growing.
- The supplied dimensions describe the tray, not the cell depth.
My Opinion
This is a sensible middle ground for gardeners who want several compact trays and moderate capacity. It offers more separation than a crowded large flat, but buyers with a substantial vegetable-starting schedule will likely find the 400-cell version more efficient.
GREENBAZZAR Seed Starter Tray
GREENBAZZAR stands apart by focusing on transplant control rather than maximum cell count. Its nine removable cells sit in a stabilizer frame, and each cell has a lift-out handle. Instead of squeezing a complete tray or pushing from the bottom, the gardener can raise one soil plug at a time, which may reduce disturbance when a seedling is ready to move.
The cells measure 1.96 inches across at the top and 2.36 inches deep. That gives each plant a more individually managed space than the densely divided high-count kits, while still keeping the overall setup suited to vegetables, herbs, and flowers in small batches. The handles can also serve as plant labels, helping identify varieties without adding a separate labeling system.
Bottom watering is built into the arrangement: water goes into the bottom tray, and five drainage openings in each cell allow the growing medium to draw moisture from below while excess water returns to the tray. This can be helpful for gentle watering, but the grower still needs to avoid leaving the bottom tray continually flooded.
The reusable modular design is attractive for someone who values cleaning and individual care. Its limitation is capacity: nine cells are not enough for a large planting plan, and the multiple pieces may require more attention when assembling, rinsing, and storing the kit.
Pros
- Lift-out handles support gentler individual transplanting.
- Nine removable cells allow separate filling and care.
- Bottom watering and five openings per cell support moisture control.
- Handles can double as plant labels.
- The parts are designed for reuse after rinsing.
Cons
- Nine cells suit small batches rather than high-volume production.
- Removable parts may take more time to organize and clean.
- The buyer must monitor bottom water to avoid excessive saturation.
My Opinion
This is the most transplant-focused option in the group. It deserves consideration when protecting individual soil plugs matters more than starting dozens of plants, especially for a gardener who prefers bottom watering and reusable components.
Living Whole Foods 10 Plant Growing Trays
The Living Whole Foods trays are different from the other selections because they are open growing flats rather than divided cell kits. The package contains 10 durable plastic trays with no drain holes, measuring approximately 21 by 11 inches at the top and 20 by 10 inches at the bottom. That broad surface is useful for microgreens, wheatgrass, hydroponic growing, or seedlings started in a shared medium.
The lack of drainage is a major design characteristic, not a minor detail. It can help retain water for hydroponic pads and micro-mats, and the trays are specifically sized to accommodate 20-by-10-inch Sure to Grow Hydroponic Grow Pads and Micro-Mats. For ordinary soil seed starting, however, the grower must manage watering carefully because excess moisture has nowhere to escape.
These flats can also function as drip trays or general greenhouse supports. Their reusable format may appeal to someone who wants a simple surface that can be rinsed and used for different growing projects over time. They do not provide individual cells, humidity domes, or built-in labels, so they require a different workflow from the four compartmentalized kits above.
Consider this option when the goal is a flat growing area rather than plug production. It is especially relevant for microgreens and hydroponic media, but it is less forgiving for beginners who want a straightforward soil-and-cell setup.
Pros
- Ten broad trays support repeated growing projects.
- The 20-by-10-inch format fits compatible hydroponic pads and mats.
- No drain holes suit certain hydroponic and drip-tray uses.
- Reusable plastic works for seedlings, microgreens, and wheatgrass.
- Large open surfaces are easy to arrange in a greenhouse.
Cons
- No drainage increases the risk of overwatering soil starts.
- There are no individual cells for separating seedlings.
- Domes, labels, and planting tools are not listed as included.
My Opinion
This is a specialized pick rather than a general replacement for a cell kit. It makes the most sense for microgreens, wheatgrass, hydroponic pads, or growers who intentionally want an open flat and already understand how to control moisture.
How I Selected These Seed-Starting Trays
I compared the seed starter trays by looking first at how clearly each design supports germination and early plant care, then at the practical details that affect daily use. Cell count, cell dimensions, tray footprint, drainage, domes, ventilation, transplant access, included tools, and reuse potential all shaped the ranking. The supplied customer-feedback evidence was also considered where available, but no hands-on testing or unsupported performance claims are presented.
Rank does not simply mean that one format is best for every garden. The MIXC kit leads because it combines five complete units with adjustable vents, stackable bases, labels, and tools, while the Mr. Pen 400-cell option is more appropriate when volume is the priority.
Best overall balance: Choose a complete multi-tray kit when you want humidity control, separated varieties, and a manageable setup.
Best specialized format: Choose an open, undivided flat only when microgreens, wheatgrass, hydroponics, or shared growing media are part of the plan.
How to Choose Seed-Starting Trays
The right seed-starting tray should match the number of plants, the space available, and the way you plan to water and transplant. A small cell kit may be ideal for herbs and flowers, while a broad no-drain flat can be better for microgreens but less forgiving for soil-based seedlings.
- Match capacity to your planting list: Count varieties and desired plants before choosing between nine, 120, 200, or 400 cells.
- Check the cell dimensions: Small cells save space but require earlier transplanting when roots and foliage develop.
- Prioritize drainage for soil: Drainage holes help move excess water away from roots; no-drain trays require more careful watering.
- Look for humidity control: Clear domes and adjustable vents are useful during germination, but covers should not remain closed indefinitely after seedlings emerge.
- Consider transplant access: Lift-out cells can be worthwhile when minimizing handling of individual soil plugs is important.
Cell count and growing space
High cell counts are efficient when starting many plants, but they also create more watering and labeling tasks. The Mr. Pen 400-cell kit is aimed at scale, whereas the 120-cell kit offers a more moderate quantity in compact 12-cell units. The GREENBAZZAR tray is better for a short list of plants that deserve individual attention.
Dome height and ventilation
A dome creates a more humid enclosed environment while seeds are germinating. Adjustable vents matter because the ideal conditions change once green growth appears; opening the vents gradually can provide more air exchange and help avoid keeping emerging seedlings in an overly enclosed space.
How to Set Up a Seed Starter Tray
Begin by placing the tray on a level, water-resistant surface with enough light for emerging seedlings. Assemble the base and dome if supplied, confirm that cells are seated correctly, and label each variety before planting so small seedlings do not become difficult to identify later.
- Fill each cell with an appropriate, lightly moistened growing medium.
- Sow seeds at the depth recommended on the seed packet rather than using one depth for every crop.
- Use a dibber or similar tool when a consistent planting hole is helpful.
- Place the tray in the base and add only the amount of water the medium can absorb.
- Use the dome during germination, checking moisture and ventilation regularly.
- Remove or open the cover as seedlings emerge and need more air circulation.
Do not pack the medium so tightly that roots and water cannot move through it. At the same time, loose or uneven filling can leave some cells dry and others saturated, so aim for a consistent fill level across the tray.
Watering and Humidity Management
Moisture should support germination without leaving roots in stagnant water. Domes reduce evaporation, so a covered tray may need less frequent watering than an uncovered container; inspect the medium instead of following a rigid daily schedule.
Top watering versus bottom watering
Gentle top watering can work for newly sown seeds, but a strong stream may displace them or expose shallow roots. Bottom watering is useful when a tray and cell design allow the medium to draw water upward, as with the GREENBAZZAR arrangement. After the medium is evenly moist, remove standing excess rather than letting the base remain continuously flooded.
When to vent the dome
Adjustable vents should be treated as a gradual transition tool. Increase ventilation as seedlings appear, and pay attention to condensation, surface moisture, and the condition of the young stems. A clear cover is helpful for observation, but it should not replace regular attention.
Transplanting Without Unnecessary Root Disturbance
Transplant when the seedlings are strong enough to handle the move and when the available cell space is becoming restrictive. Watering the medium lightly beforehand can help keep the soil plug together, but avoid pulling on the stem because it is often the most fragile part of a young plant.
Standard cells can be loosened carefully from the sides or pushed from the bottom if the tray design allows it. GREENBAZZAR’s lift-out handles offer a more direct way to raise one cell at a time, which is useful when some plants are ready before others. Regardless of tray type, hold seedlings by a leaf or the soil plug whenever possible rather than gripping the stem.
Cleaning and Reusing the Trays
Reusable trays should be emptied and rinsed after each growing cycle. Remove old roots and clinging medium from cells, bases, domes, handles, and stabilizer frames, then allow the pieces to dry fully before storage.
Pay special attention to drainage openings because compacted growing medium can block water movement. A soft brush or gentle stream can help clear openings without relying on force that might deform a small cell. Transparent domes should also be cleaned so condensation and remaining soil do not make growth harder to observe next time.
Store the components in a dry place where the domes will not be crushed. The MIXC bases are described as stackable before germination, and removable GREENBAZZAR cells can be kept together with their handles and frame so pieces are less likely to disappear between seasons.
Compatibility, Sizing, and Capacity
Measure the available shelf, windowsill, greenhouse bench, or lighted growing area before ordering. A tray’s advertised capacity does not tell you how much room multiple filled trays will require, and domes add height above the growing surface.
- The MIXC cells are 1.5 by 1.5 inches and 2 inches deep, with a 2.75-inch dome height.
- The smaller Mr. Pen set lists an overall tray size of 6.6 by 4.6 inches and 12 cells per set.
- The GREENBAZZAR cells measure 1.96 inches across at the top and 2.36 inches deep.
- The Living Whole Foods trays are approximately 21 by 11 inches at the top and 20 by 10 inches at the bottom.
Use the smallest practical cell for crops that will be moved promptly, and choose more individual space when seedlings need additional time before transplanting. For microgreens or hydroponic pads, an open flat may be more compatible than a divided propagation kit.
Common Mistakes to Avoid with Seed-Starting Trays
Most early problems come from choosing a tray for its cell count alone or treating every seed and growing medium exactly the same. A little planning prevents overcrowding, excess moisture, and difficult transplanting later.
- Overwatering covered cells: Humidity domes slow evaporation, so check the medium before adding more water.
- Ignoring drainage: No-drain flats are not automatically suitable for ordinary soil starts.
- Leaving seedlings covered too long: Increase ventilation as growth emerges and conditions change.
- Starting too many plants for the available light: Capacity is only useful when the growing area can support it.
- Skipping labels: Mark varieties at sowing, not after multiple seedlings look alike.
- Waiting too long to transplant: Small cells are intended for early growth and may not support seedlings indefinitely.
- Pulling seedlings by the stem: Lift the plug or handle the plant by a leaf when possible.
Do not choose the 400-cell format simply because it offers the largest number. A smaller, well-managed tray can produce better results when indoor space and light are limited.
Which Tray Type Fits Different Garden Plans?
For a first indoor herb garden
A compact kit with a dome and adjustable ventilation is usually easier to manage than an open flat. The MIXC or smaller Mr. Pen setup provides separated cells, while labels help keep herbs organized as they emerge.
For a large vegetable-starting schedule
The 400-cell Mr. Pen kit is designed for quantity and includes 10 complete tray sets. Make sure there is enough room for the trays, adequate light, and a plan for moving seedlings into larger containers or garden beds.
For small-batch transplanting
The GREENBAZZAR design favors one-at-a-time handling. It is a useful fit when the gardener wants to remove individual plugs rather than disturb a full tray of neighboring plants.
For microgreens or hydroponics
The Living Whole Foods open flats are the specialized choice. Their no-drain construction and compatibility with 20-by-10-inch hydroponic pads and micro-mats make them more appropriate for shared growing surfaces than for separated soil seedlings.
FAQS About Seed Starter Trays
Do seed starter trays need humidity domes?
No, but a dome can help retain moisture during germination. Vented domes are more flexible because they allow ventilation to increase as seedlings emerge.
Are no-drain seed starter trays suitable for soil?
They can be used with soil only when watering is carefully controlled. Without drainage holes, excess water can remain around the roots, so no-drain flats are often better suited to hydroponic pads, microgreens, or wheatgrass.
How many cells should seed starter trays have?
Choose based on the number of plants and the available space. A 12-cell or nine-cell format suits a small planting plan, while a 40-cell tray is more useful for starting many varieties or a larger garden.
When should seedlings be removed from a starter tray?
Move them when they are strong enough to handle transplanting and when the cell is becoming too restrictive. The correct timing varies by plant, so follow the seed packet and watch the seedling’s development.
Can seed starter trays be reused?
Several selections here are intended for reuse. Empty, rinse, clean the drainage openings and other parts, and let everything dry fully before storing the trays for another growing cycle.
Are larger cells always better for seedlings?
No. Larger cells provide more room, but smaller cells use space efficiently for early growth. The best size depends on how long seedlings will remain in the tray before moving to a pot or garden bed.
Final Thoughts
For most beginners, the MIXC 5 Pack Seed Starter Tray is the strongest all-purpose choice because it combines multiple complete units, adjustable vents, stackable bases, labels, and tools. If you need maximum capacity for a classroom, greenhouse, or large garden plan, the Mr. Pen Seed Starter Tray Kits, 10-Pack, Total 400 Cells is the better alternative. Choose according to your available space, watering habits, and transplant schedule, and the best seed starter trays will be the ones you can manage consistently.
For the final decision, my first two recommendations are MIXC 5 Pack Seed Starter Tray and Amazon.com Mr. Pen- Seed Starter Tray Kits 10 Pack Total. They are the two options I would compare first based on the ranking and buying factors covered above.
I’m Maya L. Greenwood, a lifelong plant lover who believes anyone can grow something beautiful with the right guidance. After years of testing soil mixes, pruning methods, irrigation tricks, and pest-safe solutions, I started EasyGardenTips.com to turn hard-won lessons into step-by-step advice. From seed starting and container gardens to composting and seasonal checklists, my goal is to make gardening simple, sustainable, and fun.
