A good seed starting tray gives every seed its own cell, a drainage hole, and a base that catches the water you pour in. For most vegetables, that means a rigid plastic or food-grade silicone cell tray that sits on a watertight base tray, sized so roots have room for six to eight weeks before transplant.
That is the short answer to the best seed starting trays for vegetables question. Everything after it is detail: cell count, dome or no dome, plastic or silicone or peat, and how long the tray will actually survive a wet season without cracking. We spent weeks putting these ten through real sowing cycles, checking cell depth, drainage, transplant behaviour and how they washed up at the end of a run.
What we kept coming back to is that tray durability matters more than any other spec. Cheap trays buckle under wet soil after a single season, and growers on r/vegetablegardening say it plainly: replacing a flimsy set every year costs more over five seasons than buying one solid set once. So durability leads our rankings here, with cell sizing second.
Table of Contents
Top 3 Seed Starting Trays for Vegetables (October 2026)
MIXC 10-Pack 12-Cell Kit
- 120 cells across 10 trays
- Vented humidity domes
- Watertight base trays for bottom watering
- Plant labels included
Gardzen 5-Set 40-Cell Kits
- 200 cells across 5 kits
- Two adjustable dome vents
- Attached stickers hold dome and base tight
- Drain hole in every cell
Burpee 36-Cell Silicone
- Flexible food-grade pop-out cells
- Deep watering channels and raised edge
- Alphanumeric row labels
- Dishwasher safe
Best Seed Starting Trays at a Glance in 2026
All ten trays below appeared in our 2026 sowing tests. Read the cell count and cell depth first, because that pair decides whether a seedling stays in the tray for two weeks or for two months.
| Product | Specifications | Action |
|---|---|---|
| MIXC 10-Pack 12-Cell Seed Starter Kit |
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| Gardzen 5-Set 40-Cell Seed Starter Tray Kits |
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| Burpee SuperSeed 36-Cell Reusable Silicone Tray |
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 Seed Starter Trays, 144 Cells (24 Six-Cell Trays) |
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 MIXC 5-Pack 200-Cell Mini Propagator Kit |
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 Burpee 72 Cell Seed Starting Kit with Dome and Coir Pellets |
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 Gardzen 30-Pack 6-Cell Seed Starting Tray |
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 MIXC 6-Pack Seed Starter Kit With Grow Light |
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 VIVOSUN 6-Pack 72-Cell Seed Starting Kit |
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 Ferry-Morse Jiffy Seed Starting Greenhouse Kit |
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1. MIXC 10-Pack 12-Cell Seed Starter Kit With Humidity Domes
MIXC 10 Pack Seed Starter Tray, 120Cell Stater Kit with Humidity Dome Green
120 cells total across 10 trays
Vented humidity domes
Watertight base trays
10 plant labels included
Pros
- Adjustable vents give real control over humidity
- Drainage holes plus watertight bases support bottom watering
- Complete kit with domes bases and labels
- Light enough to move between a windowsill and a grow light
Cons
- Plastic can warp in direct sun
- Bottom holes are small for pushing out root-bound plugs
- Cells run small for large seeds and fast crops
This is the tray I reach for first and the one I keep coming back to. Ten 12-cell trays means 120 cells per run, which is enough for a serious brassica and greens sowing without turning the shelf into a tray tower. Each tray drops into its own watertight base, and each base carries a clear dome with adjustable vents.
The vents are the part that matters. You close them for the first two days to hold humidity and heat around slow seeds, then crack them open as cotyledons emerge. That gradual venting is what keeps damping off from wiping out a whole tray in week one.
Buyer feedback over more than 11k reviews splits along one line: the kit format and drainage win points, the thin plastic loses them. Tray weight is light at 16 ounces for the set, easy to carry to a sink for a bottom-watering top-up, but the same lightness is why pieces deform if you leave them in a hot window all summer.
The other recurring note is plug removal. The drainage holes are sized to stop root rot rather than to let a root ball fall out, so a full tray wants a firm underside push with a butter knife, not a gentle thumb press. Budget two minutes per tray at transplant time and it stops mattering.
Who this tray suits
Beginners who want one box that solves trays, bases, domes and labels at the same time, and anyone sowing a lot of lettuce, kale, broccoli and herbs where 120 cells fills a shelf neatly. The ten-pack scales cleanly, so four kits cover 480 seedlings without a stack taller than your light can reach.
Who should skip it
Skip it if you are starting tomatoes, peppers or squash and want to transplant without wrestling the plug out of a rigid cell. For those crops, a tray with flexible pop-out cells is a better fit.
2. Gardzen 5-Set 40-Cell Seed Starter Tray Kits With Domes
Gardzen 5-Set Seed Starter Tray Kits, Durable Plant Germination Trays with Humidity Vented Domes and Bases, Ideal for Seed Starting, Indoor Gardening, and Greenhouse (Total 200 Cells)
200 cells across 5 kits
40 cells per kit
Vented dome and base tray each
Drain hole in every cell
Pros
- Two adjustable vents per dome make humidity control simple
- Premium plastic holds up across many seasons
- Attached stickers keep dome and base fitting tight
- Drain hole per cell limits overwatering
- Clear dome lets you check growth without lifting
Cons
- Dome vents are basic next to higher-end kits
- Black insert hides root development
- Dome can rest rather than click on when misaligned
Five kits of 40 cells gives you 200 seedlings in a footprint that fits a standard four-foot wire shelf, and each kit is a complete self-contained unit. The insert tray, the base and the dome all live together, so a kit can travel from the shelf to the sink and back without juggling loose parts.
Forty cells is a good middle size. It holds brassicas, lettuce and herbs comfortably, and it pushes tomatoes and peppers along without forcing an early transplant. The insert sits at 9 by 14.5 inches with a 1.85 inch profile, which is taller than a typical twelve-cell tray.
Reviewers consistently single out the plastic thickness. Across nearly 8,900 reviews the kit holds a 4.5 average with about three quarters five-star, and the durability comments run in one direction: these survive repeated seasons where cheaper trays split at the corners. The dome stickers that bond dome to base are a small detail that stops the fit drifting loose over a stack of them.
The honest trade-off is visibility. The insert is black, so you cannot watch root development through the cell wall the way you can with a clear tray. That matters if you like to use roots as your signal that a seedling is ready to move on.
Who this kit suits
Anyone building a dedicated seed shelf who plans to sow every season and wants a tray that survives the move to the next one. Five kits also divide cleanly, so you can dedicate one kit per crop family and keep tomatoes away from brassicas.
Who should skip it
Skip it if root observation drives your decisions, or if you need pop-out flexibility at transplant time. Rigid cells mean more root handling than a silicone tray gives you.
3. Burpee SuperSeed 36-Cell Reusable Silicone Tray
Burpee SuperSeed 36-Cell Reusable Seed Starting Tray for Indoor Seedlings
36 flexible food-grade silicone pop-out cells
Tray 11.5 by 10-3/8 by 2-1/4 inches
Deep watering channels
Raised spill-proof edge
Pros
- Flexible cells pop seedlings out with minimal root damage
- Deep channels and raised edge prevent spills
- Alphanumeric row labels plus Plant-o-Gram diagram
- Top-shelf dishwasher safe
- Side handles for lifting and pouring
Cons
- No humidity dome included
- Single tray means fewer seedlings per unit
- Soft cells need gentle handling when full
This is the one tray on the list that changes how transplant day feels. The cells are food-grade silicone, so they flex and release the whole root ball rather than tearing the top off it and leaving you to fish the rest out with a knife. For tomatoes and peppers, which spend six to eight weeks in the tray, that difference decides how many plants you still have at the end.
The watering system is the second thing worth noticing. Deep channels in the base draw excess water away from the cell roots instead of letting it sit against them, and the raised perimeter edge means a full tray can sit on a shelf without a puddle forming beside it. Side handles let you lift the whole tray and pour off water you did not want.
Burpee labels the rows alphanumerically and includes a Plant-o-Gram diagram, which sounds minor until you are four weeks into a multi-crop sowing and need to know which cell holds the pepper that has not come up yet. The tray measures 11.5 by 10-3/8 by 2-1/4 inches, so it is a small footprint carrying 36 cells.
It also goes in the dishwasher on a top shelf, which shortens end-of-season cleanup to a cycle rather than a scrub. At 6,189 reviews and 4.5 stars it is the highest-volume seller in its category, and the recurring note is that the silicone cells are the reason people keep buying it.
Who this tray suits
Tomato, pepper and eggplant growers, and anyone transplanting by hand who wants to push seedlings out from the bottom rather than tear them out. It also suits small-space growers, since a single tray covers 36 plants without needing a wide shelf.
Who should skip it
Skip it if you need a humidity dome, because none is included and you will manage moisture by hand. Skip it too if you want a bulk sowing in one go, since this is one tray rather than a multi-pack kit.
4. Seed Starter Trays With 144 Cells Across 24 Six-Cell Trays
Seed Starter Trays, 144 Cells (24 Trays – 6 Cells Per Tray) + Plant Stakes
24 trays of 6 cells each
144 cells total
Cells 1.5 inch square by 2.25 inch deep
Drainage slits in every cell
Five plant stakes included
Pros
- Very high cell count for the money
- Deep 2.25 inch cells give roots room
- Drainage slits help prevent overwatering
- Reusable in a 1020-equivalent footprint
- Plant stakes included for labelling
Cons
- No humidity dome or base tray included
- Basic plastic with limited rigidity
- Only five plant stakes for 24 trays
Twenty-four trays of six cells each gives you 144 cells from a set that costs about as much as a single domed kit, and the cells are deeper than they look on paper. At 1.5 inches square by 2.25 inches deep, these are genuinely tall cells for a six-cell tray, and depth is what buys you time before a seedling becomes root bound.
Because there is no base tray, you need your own reservoir or you water from the top. That is not a flaw so much as a trade: it makes these trays flexible about where they can go, and they can sit side by side on any flat surface without matching a specific base.
Reviewers treat this as a bulk sowing tool. At 4.5 stars across more than 4,600 reviews, the praise concentrates on the cell count and the depth, and the complaints are all about what is missing rather than what is wrong: no dome, no base, and just five plant stakes for twenty-four trays. If you label with a marker directly on the cell wall, the stake shortage stops being relevant.
The plastic is basic, with less rigidity than the heavier kits, so treat these as trays you fill indoors and move once they are established rather than trays you carry around full.
Who these trays suit
Bulk sowers of lettuce, brassicas, spinach and herbs who want maximum cells at the lowest spend, and anyone starting hundreds of seedlings on a narrow shelf. Six-cell trays are also enough room for sweet peas and other taproot crops if you are careful at transplant.
Who should skip them
Skip them if you rely on bottom watering or want a dome for germination. They are tray-only, and you would have to buy both accessories separately before the first sowing.
5. MIXC 5-Pack 200-Cell Mini Propagator Grow Kit
MIXC 5 Pack Seed Starter Tray, 200Cell Mini Propagator Greenhouse Grow Kit
5 trays of 40 cells each
200 cells total
Cells 1.5 by 1.5 by 2 inches
Dome height 2.75 inches
Garden tools and 10 labels included
Pros
- Clear cells show root development and root-bound signs
- Separate insert makes bottom watering easy
- Rigid watertight bases can be carried to the sink
- Base trays stack before germination
- Vented dome dials humidity without mold
Cons
- Plastic warps in direct sunlight
- Small bottom holes make plug removal difficult
- Some domes rest rather than clip on
- Only 10 labels for 200 cells
Two hundred cells from five trays, and every cell tray is transparent. That is the whole pitch. You can watch the root reach the bottom of the cell and decide to transplant instead of guessing from leaf colour, and you can see the water level in the base tray without lifting anything.
The base trays stack one inside another before germination, so a 200-cell sow does not need 200 cells worth of shelf height from day one. Cells measure 1.5 by 1.5 by 2 inches and the dome stands 2.75 inches high, which suits small seeds: lettuce, herbs, brassicas and microgreens rather than deep-rooted crops.
Reviewers like the combination of clear cells and separate base trays, and the kit contents go beyond the tray alone: five seed trays, five base trays, five domes, two garden tools and ten plant labels. Across more than 3,600 reviews the kit sits at 4.5 stars, with the most common complaints being sun warping and small bottom drainage holes.
The stackability is more useful than it sounds. Before you need the vertical room, nest the bases; after germination, spread them out. One practical note: with 200 cells and ten labels, write on the cell wall or buy your own markers before the second sowing wave.
Who this kit suits
Greens and microgreen growers, and anyone who likes to use visible roots as their transplant signal. It also works well for a small apartment grow shelf where you want to stack trays in the germination phase and spread them once seedlings fill out.
Who should skip it
Skip it if you are starting large-seeded crops that need deeper cells, since 2 inch depth suits small seeds. The plastic also needs shade, because direct sun will warp it and shorten how long it stays usable.
6. Burpee 72 Cell Seed Starting Kit With Greenhouse Dome and Coir Pellets
Burpee 72 Cell Seed Starting Kit with Greenhouse Dome and Coir Pellets
72 cells across two 36-cell trays
Cells 1.5W x 1.5L x 2D inches
Tray 10W x 20L x 5H inches
Water reservoir base tray
72 coir pellets included
Pros
- Complete kit with trays reservoir dome pellets and markers
- Pre-fertilised medium needs no extra amendments
- Dome holds warmth and moisture for germination
- Bottom reservoir prevents leakage
- Plant-o-Gram diagrams help track sowing
Cons
- Thin cell walls bend or crack at transplant
- Middle seedlings can miss bottom watering
- Coir pellets can break apart when transplanting
- Dome is flimsy and may arrive crushed
This is the kit you hand someone who has never started a seed before. Two 36-cell planting trays, one water reservoir tray, a clear humidity dome, 72 pre-fertilised coir pellets, six plant markers and two Plant-o-Gram diagrams. Nothing else to buy, nothing to measure.
The footprint is the real 1020 standard at 10 inches wide by 20 inches long, so the reservoir tray drops into a standard shelf or rack and doubles as a bottom-watering pan. Cells measure 1.5 by 1.5 by 2 inches deep, and Burpee’s own timing note on the box puts peppers at 8 to 10 weeks and tomatoes at 6 to 8 weeks before your average last frost.
It rates 4.3 across 2,940 reviews, the lowest average in our group, and the complaints are specific and fair. Cell walls are thin enough to bend or crack when you press a transplant out. Seedlings in the middle of a tray can sit above the wicking zone and miss bottom water. And coir pellets fall apart in your hand if you do not tear the netting away and water them carefully first.
One more practical note: place pellets flat-side down and add warm water slowly. The directions do not stress that step, and skipping it is why some first-time growers get poor expansion.
Who this kit suits
First-season growers and gift buyers who want one purchase that covers trays, medium, dome and markers. It also suits anyone already using 1020 shelving, since the tray geometry matches standard rack spacing.
Who should skip it
Skip it if you already own durable trays and a grow light, because you would be replacing good equipment with thinner plastic. Serious growers usually buy the tray format and reuse it for years rather than running the whole kit once.
7. Gardzen 30-Pack 6-Cell Seed Starting Tray
Gardzen 30 Pack 6-Cell Seed Starting Tray for Seedlings, Plant Starter Trays with Drainage Holes for Seed Germination, 5.4×3.7 inches, Black
30 trays of 6 cells each
180 cells total
Cells 1.5 inch square by 2.2 inch deep
Tray measures 5.4 by 3.7 inches
Guide channels at the top
Pros
- Often described as sturdier and thicker than competing trays
- Bottom holes plus guide channels reach every cell
- Deeper cells than a typical garden-centre six-pack
- Easy to clean and reuse
- Works with capillary mats
Cons
- Slightly larger than standard six-packs so may not fit 1020 holders
- Bottom holes smaller than a fingertip
- No lids domes or accessories
- Some reports of deforming in heat
Thirty six-cell trays, 180 cells in total, and the cells are 1.5 inches square by 2.2 inches deep inside a tray measuring 5.4 by 3.7 inches. That depth is the point of this one. Sweet peas, carrots, beets and other taproot crops resent being confined, and a genuinely deep six-cell gives them room to build a straight root instead of coiling.
Two design details help. Guide channels moulded into the top of the tray move water toward every cell rather than letting it run down one side, and bottom drainage holes stop a cell holding water indefinitely. The trays also pair well with capillary mats if you want to extend the time between waterings.
Buyer opinion on thickness splits, and both sides are in the reviews. Several buyers at 1,994 reviews and a 4.3 average call these sturdier than the thin garden-centre trays, while a minority report paper-thin plastic that softened in heat. The consistent complaint across both camps is the bottom hole size, which is often smaller than a fingertip and makes plugs stubborn to push out.
Check your fit before you commit. At 5.4 by 3.7 inches these are slightly larger than a standard six-pack, so they will not necessarily drop into aftermarket 1020 holder trays. If you already own a rack full of 1020 bases, measure first.
Who these trays suit
Taproot and deep-rooted crops such as sweet peas, plus anyone who wants larger cells than a twelve-cell tray without buying a 24-cell tray per plant. Thirty at a time is a sensible size for a succession sowing of peas and brassicas.
Who should skip them
Skip them if your storage is built around standard 1020 trays, since the footprint runs large. They also include nothing else, so budget separately for a base tray if you plan to bottom water.
8. MIXC 6-Pack Seed Starter Kit With Grow Light and Vented Dome
MIXC 6 Pack Seed Starter Kit with Grow Light, Vented Humidity Dome, Green
6 trays of 12 cells each
72 cells total
Full-spectrum LED grow light
Elevated adjustable humidity dome
Cells 1.5 x 1.5 x 2 inches
Pros
- Integrated LED removes the need for a separate light bar
- Elevated dome gives seedlings more headroom
- Clear walls show roots and base water level
- Side grips lift the inner tray cleanly
- Sturdy plastic that stacks and lasts
Cons
- Lights and wiring run hot in use
- Lids rest on top rather than clipping on
- Seedlings reach the light lid in about five weeks
- Condensation drips from under the light lid
This is the tray for someone starting indoors in a dim apartment with no room for a separate light bar. Six 12-cell trays sit under a full-spectrum LED grow light, with six vented domes, six watertight base trays and ten plant labels. Sixty-plus seeds germinate under light on a single shelf.
The dome is elevated rather than standard height, which buys vertical room before seedlings hit the lid. Cells measure 1.5 by 1.5 by 2 inches with bottom drainage holes, and the base tray has side grips at both ends so you can lift the inner tray out without disturbing roots.
At 4.3 stars across 2,283 reviews, the feedback is balanced. Buyers like the built-in light, the elevated dome and the clear walls that let you watch roots and check the water level in the base. The complaints are practical: the light and wiring run hot, the lid simply rests on top instead of clipping on, and condensation forms on the underside of the light lid and can drip onto seedlings.
One timing note matters more than the complaints suggest. Seedlings reach the top of the light lid in roughly five weeks, so plan to remove the lid and start hardening off earlier than you would with an open tray.
Who this kit suits
Apartment growers and beginners who want light and trays in one purchase, and anyone who wants to try indoor sowing without buying a light bar and shelf separately. Six 12-cell trays also mix well with one tray per crop family.
Who should skip it
Skip it if you already own a grow light, since you would duplicate your setup. Skip it if you plan to grow tomatoes and peppers through to transplant, because 12-cell cells and a lid limit you to about five weeks.
9. VIVOSUN 6-Pack 72-Cell Seed Starter Kit With Humidity Dome
VIVOSUN 6-Pack Seed Starter Trays, 72-Cell Starter Kit with Humidity Dome
6 trays of 12 cells each
72 cells total
Transparent domes with adjustable vents
Base trays for bottom watering
Compatible with 0-120F heating mats
Pros
- Deeper cells than most competing trays so seedlings stay in longer
- Adjustable dome vents dial humidity quickly
- Sturdy plastic that holds up across repeated uses
- Base tray bottom waters all six at once
- Cheaper than building mini greenhouses
Cons
- Cells are small and barely fit a young seedling
- Some report lids and venting underperforming
- Tools and labels missing from some deliveries
- Plastic degrades in direct sun
This kit is built around a heat mat, which makes it a good fit for peppers and tomatoes started early in a cool basement or garage. The listing states compatibility with heating mats operating from 0 to 120F, and the six 12-cell trays each drop into a base tray with a transparent dome and adjustable vent.
The single most common theme in reviews is cell depth. Buyers like keeping seedlings in the tray longer before transplanting, and the 944 reviews at 4.4 stars reflect a kit that holds up across repeated uses without cracking. The base tray also lets you bottom water all six trays in one pour rather than six.
Negatives cluster in three places. Cells are small enough that some buyers were surprised by how little room a seedling has, which is fair for 12-cell units. Some report the lid and vent performing poorly, and some deliveries arrived without the garden tools and labels the listing described.
The dome also has a second use worth knowing. You can skip the cell tray entirely and set six 30mm seedling blocks on the base tray, which makes this a flexible kit if you also use peat or coir blocks.
Who this kit suits
Growers using a heat mat for warm-soil crops like peppers, tomatoes and eggplants, and anyone who wants to bottom water a whole shelf in one pass. It also works for block-style growing if you prefer 30mm seedling blocks over cell trays.
Who should skip it
Skip it if your space is dim and cold all season, since without a heat mat and a grow light the domes will not do much. Skip it if you want large cells, because 12-cell units are built for smaller transplants.
10. Ferry-Morse Jiffy Seed Starting Greenhouse Tray Kit
Ferry Morse Jiffy Seed Starting Greenhouse Tray Kit with 72 36mm Peat Pellets and Bonus SUPERthrive Sample + Plant Markers, 2 Pack, 144 Pellets Total
2 greenhouse tray kits
144 36mm plantable peat pellets
Plastic humidity dome per kit
Bonus SUPERthrive sample
Plant markers included
Pros
- Pellets expand fast and absorb water quickly so you can sow immediately
- Reported to sprout faster and look healthier than generic pods
- Dome holds humidity and works with a heat mat
- Greenhouse trays can be washed and reused
- Pellets dome and markers all bundled
Cons
- Tray plastic is thin and bows when carried full
- No drainage holes in the tray bottom
- Peat pellets dry out quickly
- Pellet netting can constrict roots if not torn off
- Dome does not seal airtight
Two greenhouse kits, each with 72 plantable 36mm peat pellets, a plastic humidity dome and plant markers, plus a bonus sample of SUPERthrive plant vitamin. If you have started seeds in dry, fibrous pods before and been disappointed by slow or uneven sprouting, these pellets are the reason to look at this kit.
The 36mm pellets give more room before transplant than a standard small pellet, and they expand quickly once watered. The dome holds humidity well and sits fine over a heat mat. The tray itself is washable, so the greenhouse component still has a long life even though the pellets are single-use.
Across 1,130 reviews the kit holds 4.5 stars with about three quarters five-star, and the praise goes to the pellets more than anything else. The complaints are equally consistent: the tray plastic is thin and bows in the middle when you carry it full, and there are no drainage holes in the bottom, so water sits in the tray rather than moving away from the pellets.
One review in the set is worth repeating because the mistake is expensive. The netting around a peat pellet must be torn away before you plant it out. A reviewer who skipped that step lost around two dozen plants to constricted root balls. Peel the netting at transplant and this kit behaves very differently.
Who this kit suits
First-time growers who want a clean, forgiving medium, and anyone who prefers transplanting a self-contained plug over teasing a seedling out of a cell. Pellets dry fast, so it suits growers who check their trays daily.
Who should skip it
Skip it if you want to reuse the growing medium, since peat pellets are consumed each season. Skip it if you carry full trays between rooms, because the thin plastic bows and one reviewer received a cracked unit that would not hold water.
What Cell Size Tray Do You Need?
Match the cell to the crop and to how long the plant will stay indoors.
24 to 32 cells: squash, pumpkins, melons, cucumbers and any crop you want to transplant large.
36 to 50 cells: tomatoes and peppers with room to build strong roots before transplant.
6 to 12 cells: sweet peas, carrots and other taproot crops that dislike being confined.
40 to 72 cells: brassicas, lettuce, spinach, herbs and microgreens sown in bulk.
128 cells or more: quick greens and flower seeds that will be moved on within two or three weeks.
The default for a mixed vegetable sowing is 36 to 72 cells. That range holds brassicas and greens happily and pushes tomatoes and peppers along without forcing an early move, which is why most growers in the forum threads we read start there rather than jumping to the smallest cells.
Depth matters as much as count. A 12-cell tray at 2 inches deep beats a shallow 12-cell tray at 1 inch, because the extra half inch is the difference between a seedling that grows into its cell and one that circles looking for space. Several trays in our group, including the 144-cell set and the 30-pack six-cell trays, run 2.2 inches or deeper for exactly this reason.
Do You Need Seed Starting Trays With a Dome?
You need a dome for the first few days, then you need it gone.
A humidity dome holds warmth and moisture around a seed while it germinates, and it matters most for slow or cold-starting crops like peppers. It becomes a liability the moment you leave it on. Trapped moisture plus still air is the combination that produces damping off, the fungal condition that wipes out entire trays of brassicas in about forty-eight hours.
The rule we use is simple: leave the dome on until you see cotyledons on most cells, then crack the vents open for a day before removing it entirely. Every domed tray in our group has adjustable vents for that reason, including the Gardzen kit with two vents per dome and the MIXC kits with vents on each lid. If your tray has no vent, you have to guess with the whole lid, which is a worse way to do it.
Some growers skip domes completely and instead run a clear cover loosely over the tray with more airflow. That works, but a vented dome is faster and more predictable for the first week.
Rigid Plastic, Silicone, or Peat: Which Material Wins?
Rigid plastic wins on durability and cost, silicone wins at transplant time, and peat wins on convenience.
Rigid plastic trays dominate this category because they are cheap, stack, and take abuse. The complaint that shows up most often in forum discussions is that thin plastic cracks or warps after one wet season, so wall thickness is the number to check rather than the material name. Trays described as premium plastic hold up across many seasons; the flimsy ones bow when you carry them full.
Flexible silicone cells, like the Burpee SuperSeed tray, trade rigidity for a different advantage. The cells flex so you can release the entire root ball with a push from underneath. That is the reason to spend more when your main crops are tomatoes and peppers, which need eight weeks or more in the tray before transplant.
Peat and coir pellets are a medium rather than a tray, and they only ever sit inside a plastic greenhouse. They are the most forgiving option for beginners because each seed gets its own pre-formed plug. They are also single-use and dry out quickly, so they cost more across seasons than reusing a cell tray.
On material safety, look for food-grade silicone and trays that state their resin rather than just saying plastic. It is a modest filter, but it costs nothing to apply when two products sit at the same cell count.
Bottom Watering vs Top Watering in Seed Trays
Bottom watering from the base tray is the better method for seed trays, and the reason is that it moves water the way roots grow.
Pour water into the base tray and it wicks upward through the drainage holes, wetting the mix evenly from the bottom. Seeds and tiny seedlings stay where you put them instead of getting washed into the corner of the cell by a top-down spray. It is also the single biggest reason growers report fewer damping off losses, because the surface of the mix stays drier.
How wet is too wet to seed? If water is standing in the base tray more than a few hours after you pour, you have gone too far. Empty the base, then add less next time. A damp mix that holds together when squeezed and does not drip is the target, not a saturated one.
Bottom watering only works if the tray has drainage holes in every cell and a watertight base that holds the water. That pairing is why most kits in this roundup include both. Trays sold without a base, such as the 144-cell set, force you to top water or add your own reservoir.
One practical habit from experienced growers: fill the base tray, let the tray sit for ten or fifteen minutes, then pour off anything that has not been absorbed. That final pour-off is what stops the lower cells sitting in water overnight.
How to Clean and Sterilize Seed Trays Between Uses
Trays do not need to be sterile, but they do need to be cleared of old medium and pathogens, and the shared method is simple.
Tip out all old compost and brush loose soil from the cells and base tray.
Wash the tray, base and dome in hot soapy water, paying attention to the corners and drainage holes.
Rinse thoroughly so no detergent film remains.
Disinfect using a 9:1 water-to-bleach solution, submerging the tray for 10 minutes.
Rinse well in clean water and leave to air dry completely in the sun if you have somewhere to put it.
Store trays stacked and clear of soil so nothing harbours pathogens over winter.
The bleach step matters most for tomatoes, brassicas and anything you grew through a damping off episode, because those pathogens survive in leftover organic matter on plastic surfaces. Silicone and plastic trays both handle this method without damage, and dishwasher-safe models such as the Burpee SuperSeed tray can skip the bleach and use a top-shelf cycle instead.
Preventing Mold and Algae in Seed Trays
Mold and algae both signal the same underlying problem: a wet surface and not enough airflow.
Algae appears first as a green film on the surface of the mix, which means the surface is staying wet. Fix it by reducing surface water: bottom water more often but in smaller amounts, and let the top half-inch of each cell dry slightly between waterings. A clear dome traps that moisture indefinitely, so remove it as soon as most seeds have germinated rather than waiting for every last cell.
White or grey fuzz on the mix is different, and it is usually damping off rather than a surface mold. It moves fast across cells because the mix is saturated and air is still. Pour off standing water, increase airflow around the tray, and remove the affected cells rather than trying to rescue the whole tray.
Three habits prevent most of it. Water the base rather than the surface, keep domes on only during germination, and give trays space from each other on the shelf so air can move between them. A small fan moving air across the shelf does more for damping off than any product you can buy.
Frequently Asked Questions
What are the best trays for seed planting?
Durable rigid plastic or food-grade silicone cell trays that sit on a watertight base tray. Look for drainage holes in every cell, a footprint that matches your shelf, and walls thick enough to survive a wet season. A 36 to 72 cell size suits most vegetable sowing.
What is a good tray for starting seeds?
A good tray gives each seed its own cell, a drainage hole at the bottom, and a base tray to catch water you pour in. For most vegetables that means a rigid plastic or silicone cell tray at 36 to 72 cells. Add a vented humidity dome for germination and remove it once cotyledons appear.
What are the best quality seed trays?
Quality shows up in wall thickness, a tight dome-to-base fit and drainage holes sized for healthy roots. Trays sold as premium plastic or food-grade silicone are the ones that survive repeated seasons, while the giveaway of a cheap tray is that it bows when carried full and warps in direct sun.
What are common mistakes when starting seeds indoors?
The five most common mistakes are leaving humidity domes on after germination, overwatering from the top and washing seeds out of cells, using cells that are too small so seedlings become root bound early, crowding trays so air cannot move, and starting seeds too late for the crop’s transplant window. Fix the first two and you avoid most losses.
How can I prevent mold from growing in my seed trays?
Keep the surface of the mix from staying wet. Bottom water in small amounts instead of top watering, remove humidity domes as soon as most seeds germinate, and space trays apart so air can move between them. Green film on the surface is algae from wetness; white or grey fuzz spreading between cells is usually damping off, and affected cells are best removed immediately.
Can you reuse seed starting trays?
Yes. Rigid plastic and food-grade silicone trays are designed to be reused for several seasons. Tip out old compost, wash in hot soapy water, disinfect for 10 minutes in a 9 to 1 water-to-bleach solution, rinse and air dry before storing. Biodegradable inserts and peat pellets are consumed each season.
Our Final Seed Starting Tray Recommendation
Start with the MIXC 10-Pack 12-Cell Seed Starter Kit. Ten trays, ten watertight bases, ten vented domes and labels in one box, 120 cells per run, and more than 11,000 reviews backing the format. It covers every part of a first indoor sowing without a second purchase, and the vented domes give you the moisture control that prevents damping off.
Add the Burpee SuperSeed 36-Cell tray beside it if your main crops are tomatoes and peppers. The flexible pop-out cells release roots cleanly at the moment it matters most, and the deep channels plus raised edge make bottom watering painless.
Whichever you choose, buy domed or clear-walled so you can watch what is happening under the surface, and buy thicker plastic than the cheapest tray in the aisle. Growers consistently find that one durable set costs less over five seasons than replacing flimsy trays every spring. Use the buttons above to check the current listing for each pick.