Order Seed & Plant Starter Trays (2024)

Mar. 06, 2024

Order Seed & Plant Starter Trays

Cell propagation trays

Start your seedlings in cell trays for space-saving advantages. Cell plug trays are the perfect tool for market gardeners that want to start more market crops at once. Another advantage is that you will waste less growing media starting out your seeds and then up-potting the successfully germinated starts into new pots.

What Size Cell Tray Should I Use?

Our propagation trays are available in several configurations and are made of extra-strong, BPA-free, food-safe plastic backed by a 1-year warranty. Discover which size cell tray will work for your greenhouse or garden plants. The cell tray guide below will help you in making the decisions about which tray is best for your operation. Or take our Garden Seed Tray Style Quiz.

Whether you are a homesteader growing food for your family or a large-scale production farm looking to streamline your transplanting process with trays that will last season after season. If you need more help making a decision please check out our article onSelecting the Right Cell Tray for Seed Starting.

6 Cell Individual Seed Starter Trays

Our newly redesigned6 cell trays have large 5/8 inch drainage holes on the bottom making it easy to remove your plant starts. They also make use of air pruning technology with long vertical slits on all 4 sides to prevent root circling in your seedlings. For easy color coding and tracking or your starts we are super excited to also offerour6-cell trays in 5 cheerful colors. These are great for gardeners who will be starting a small amount of lots of different varieties as you can remove each type as it is ready without disturbing all the other starts that are sharing its heavy-duty 1020 deep tray bottom watering tray. 12 fit in each 1020 tray.

32 Cell Seed Starter Trays

The32 cell plug propagation tray insertsare the largest seed starting cell tray size, measuring 2" x 2". The added space allows plants to develop their canopy and allows them to stay in the cells of the tray longer than they would in a tray with less volume of potting soil. When used in conjunction with ourseed starter insert pots, these are typically the best trays for seed starting for the home gardener.

50 Cell Seed Starter Trays

These50 cell propagation traysgive ample room for seedlings to develop while allowing for a larger number of seeds to be planted in the 10”x 20” space. Plants grown in these plug trays will be less likely to become root-bound if unsettled Spring weather delays your planting schedule. This size also allows for larger canopy development in the seedling.

72 Cell Seed Starting Trays

The72 Cell traysare the most popular choice amongst market gardeners. They are a good balance between space for growing and the number of seedlings per cell in the tray. Each of the individual cells is 1.5" square and 2.25" deep. This sizing is perfect for starting many different plants including vine crops. These 72 plug trays are compatible with theheavy-duty 1020 deep trayfor bottom watering.

Air Prune Propagation Tray 72 Cell

Get the air pruning benefits of soil blocking without the mess! These farm trays allow for airflow above and below the soil, so newly established seedlings get optimal growing conditions for a strong start. Our newest 72 cell air pruning tray can be used to grow everything you would use a traditional 72 cell tray for but can also keep plants growing for longer without root circling becoming an issue. These also fit nicely in ourheavy-duty 1020 deep tray.

128 Seed Propagation Trays

These128 Cell Traysare a great choice for seed starting trays if you wish to start row crops or many baby greens. This configuration is ideal for starting many seeds but is not meant for crops that need to be grown in protection for more than a few weeks. Each of the cells is 1" square and 2.25" deep. You will be able to plant 78% more seedlings with one tray than the more common 72 Cell starter tray.

These 128 plug trays are compatible with theheavy-duty 1020 deep tray for bottom watering. You will want to up-pot your seedlings from this size intolarger potsorgrow bagsif you do not plan to transplant outdoors for an extended period of time to prevent seedlings from becoming root-bound.

200 Cell Propagation Trays

These200 Cell Traysare excellent seed starting trays if you want to be economical about growing cole crops, lettuces, and other small-seeded crops. You will be able to start ~2.8 times as many seedlings with one tray as you would with a 72 cell tray. Each of the cells is 0.75" square and 2.25" deep.

Interested in learning more about seed starting? Be sure to check out ourSeed Starting Blogs.

The Beginner’s No-Fail Guide to Starting Seeds Indoors

If you're new to seed starting, this foolproof beginner's guide to starting seeds indoors will take you step by step from seed to harvest, quickly and easily. You don't need any fancy gear or grow lights to get started, and you can even upcycle small containers to put your seeds in. All that's needed is a sunny window, a basic seed-starting mix, and something underneath your pots to catch drips.

Exactly as the title says — this is an easy, no-fail guide to indoor seed starting.

You don’t need to read any gardening books first. You don’t need any fancy equipment. You just need your seeds (these are the best garden seed catalogs that I order from every year) and a few basic supplies to get started.

Whether you have a dedicated vegetable bed in your backyard, or a cluster of containers on your patio, it all starts out the same way. You have to plant your seeds, and germinating seeds inside your home (where you have the most control) is the best way to do so, especially for seeds that are hard to start.

Starting seeds indoors is ideal if you want to get a head start on the season, or if the weather is still too hot or too cold to put anything in the ground.

Related: Find First and Last Frost Dates Accurately with This Custom Planting Calendar

This simple step-by-step tutorial will take you from seed to seedling with a minimum of fuss. Just the stuff you need to know, and none that you don’t. (But if you’re the really-need-to-know type, I’ve added footnotes at the end to explain why you’re doing what you’re doing.)

Disclosure: All products on this page are independently selected. If you buy from one of my links, I may earn a commission.

How to start seeds indoors: a step-by-step guide

Step 1: Gather your seed starting supplies.

Seeds

Seed starting pots or cell trays

Plant markers

Seed starting mix (homemade or store-bought)

Seed tray with humidity dome (often called a 1020 plant tray or propagation tray, or use any DIY drainage tray with plastic wrap)

Spray bottle or squirt bottle filled with water

If you’ve already made your recycled newspaper pots, you’re all set. If you’ll be using other seed starting pots or cell trays, make sure they’re clean.1

You can also repurpose household items into seed starting containers, like egg cartons, Dixie cups, and yogurt cups. Just wash them out and poke a few drainage holes in the bottom with a nail or an awl.

Step 2: Fill your pots or trays with seed starting mix.

Dump your seed starting mix into a large tub or bucket, pour in a generous amount of water, and stir it up with your hands or a trowel.

As the seed starting mix starts to absorb the moisture, add more water as needed. (This will take several minutes, as peat-based seed starting mixes are slow to absorb.) You want the mix to be uniformly damp, like wet sand.

Fill your seedling pots with this pre-moistened seed starting mix.2

Step 3: Sow your seeds.

Place two to four seeds on the surface of the seed starting mix, and gently press the seeds down so they’re nestled in nicely.

If your seeds are very small, like basil or mustard, you can leave them uncovered.3

If your seeds are larger (like beans or peas) or they require darkness to germinate (check the instructions on the seed packets), cover them with a layer of vermiculite or seed starting mix equal to their height, usually 1/4 inch to 1/2 inch.

Step 4: Label your newly planted seeds.

Label each pot. Trust me, you will never remember what you planted where, as most seedlings look the same at birth.

At this early stage, cheap plastic plant markers work very well and stay out of the way, so save your big and beautiful metal plant markers for the garden.

Step 5: Keep your seeds moist and warm.

Mist your seeds with water.4

If your dome has vents, keep them open to help with air circulation during the sprouting period.

Now, you need to add heat. Since sunlight is not essential at this point, your seed trays can be placed wherever it’s warmest in your house, such as an attic, bathroom, laundry room, or kitchen.6

If your seedling pots stay covered in a warm nook, the low humidity will keep your seeds happy until they sprout. High humidity will make them sad. Only spritz the seeds with more water if the mix feels dry to the touch.7

Within a couple of days to a couple of weeks, the seeds will germinate. As your seedlings start to emerge, some of them will look like they’re wearing little seed hats.

Germination (the process of a seed sprouting) is highly variable, so don’t stress if it feels like it’s taking forever to happen. In most cases, seeds will germinate within three weeks (after that, try starting a new round of seeds).

Step 6: Give your new seedlings light.

At this stage, the newly germinated seedlings need light. Remove the humidity dome or plastic wrap, and move the seedlings to the sunniest spot in your house (preferably a south-facing window).

Continue to keep the mix moist, but not overly wet. Seedlings should be watered once a day or every other day, depending on how much sun and heat they get.

Remember that seedling roots are fairly close to the surface and they’re growing in a small amount of media, so they don’t need a deep soak the way larger plants do.

I like using spray bottles or squirt bottles, as the gentle streams of water won’t displace seeds or damage seedlings.

Step 7: Moving day! Transplant the strongest seedlings when they’re ready.

After your seedlings develop their first “true set” of leaves, they are ready to be transplanted.8

If more than one seed sprouted, choose the strongest one and pinch or snip off the others. You can even keep all of them, but be careful separating the roots if the seedlings are close together.

Transplant the seedling into a larger container filled with potting mix. Hold it by the cotyledons (the first leaves that appear) and try not to manhandle the tiny roots.

At this stage, you can lightly drench the potting mix using a diluted solution of compost tea or all-purpose fertilizer. Keep it simple, keep it organic, and don’t obsess too much over the nutrients.9

Give the seedling plenty of sunlight each day (at least 12 to 16 hours is optimal for most vegetable seedlings) to avoid the “leggy” look. (Learn how to fix leggy seedlings if this is happening to you.)10

Step 8: Harden off those seedlings.

To get your seedling prepped for a good life outside, you can start to harden off the seedling11 by moving it outside under diffused light for a few hours and bringing it back inside each night.

Over the next week, move it from diffused sun to partial sun to full sun, and for longer periods of time, until it’s finally kept outside all night.

Step 9: Transplant your seedlings outdoors.

After the hardening off period, you can transplant your seedling to its final destination, whether straight into your garden or into a larger container.

And then, in a couple of months, you can enjoy the fruits (and veggies) of your loving labor!

More Ways to Start Seeds Indoors

There's more than one way to start your seeds and make sure they sprout!

Germinate Seeds Quickly With Coffee Filters or Paper Towels

Whether you're trying to start tricky seeds with long germination times, or find out if your old seeds are still viable, the coffee filter (or baggie) method is a quick and simple way to start many seeds at once in a small space.

How to Start Seeds in Eggshells, Save Money, and Have Fun

Save those cracked eggshells, upcycle your egg carton, and bookmark this indoor gardening DIY for a rainy day. Starting seeds in eggshells is a fun and easy project that kids will delight in helping with!

How to Soak Seeds to Speed Up Germination Time

If you've had trouble with seeds not sprouting, soaking them in water before you sow them can greatly increase their chances of germinating. This method works well with legumes, beets, squash, and other thick-shelled seeds.

How Long Do Seeds Last? (+ Cheat Sheet on Seed Expiration Dates)

How old is too old? All seeds have a shelf life, but their longevity depends on the quality and condition when you bought or saved them, and how they've been stored since. Find out whether you should keep or toss your seed stash.

1 This seems obvious, but laziness gets the best of us. Clean pots are key and help keep damping off at bay (an untreatable fungal disease that causes seedlings to suddenly keel over and die at the soil line).

Discard or thoroughly wash any pots that previously housed diseased plants. Avoid using leftover soil from the nursery container you brought home, as it might harbor weed seeds and bad bacteria.

If you have a healthy garden, you can skip washing your pots and simply dump out the dirt from your pots before using again.

I’ve put countless seed trays and humidity domes to the test over the years, and found these trays and domes to be the thickest and strongest on the market — they don’t bend, flex, or crack as easily as other brands, and can be reused for many seasons. back

2 It’s easier to start with pre-moistened mix, as peat-based mixes are harder to wet down uniformly if they dry out in pots. Although peat has a very high water-holding capacity once it’s wet, it actually repels water when it’s dry. Go figure.

If you’re not using homemade seed starting mix, this is a reputable brand that I like. You do not need anything fancy; seeds just need a basic mix of perlite, vermiculite, and peat moss (or coco coir) to germinate and grow into healthy seedlings. back

3 For certain varieties of plants, light will often speed up germination (the process of a plant sprouting from a seed). back

4 The moisture will help the seeds shed their protective coating and eventually sprout. back

5 This creates a greenhouse effect to keep your seeds moist and warm, the key to germination. Most annual vegetables germinate best in temperatures of 75°F to 90°F. A few, such as radish, will germinate at lower temperatures.

Seeds will sometimes sprout in less than ideal temperatures, but the germination period will be longer. back

The Beginner’s No-Fail Guide to Starting Seeds Indoors

If you're new to seed starting, this foolproof beginner's guide to starting seeds indoors will take you step by step from seed to harvest, quickly and easily.

Prep Time

15 minutes

Active Time

15 minutes

Total Time

30 minutes

Difficulty

Easy

Materials

Seeds

Seed starting pots or cell trays

Plant markers

Seed starting mix (homemade or store-bought)

Seed tray with humidity dome (often called a 1020 plant tray or propagation tray, or use any DIY drainage tray with plastic wrap)

Spray bottle or squirt bottle filled with water

Tools

Large bucket or tub

Trowel

Instructions

Gather your seed starting supplies. Instead of seed starting pots, you can also use recycled newspaper pots, or repurpose household items into seed starting containers, like egg cartons, Dixie cups, and yogurt cups. Just wash them out and poke a few drainage holes in the bottom with a nail or an awl.

Fill your pots or trays with seed starting mix. Dump your seed starting mix into a large tub or bucket, pour in a generous amount of water, and stir it up with your hands or a trowel.

Fill your seedling pots with this pre-moistened seed starting mix.

Sow your seeds. Place two to four seeds on the surface of the seed starting mix, and gently press the seeds down so they’re nestled in nicely.

If your seeds are very small, like basil or mustard, you can leave them uncovered.

Label your newly planted seeds. Label each pot. At this early stage, cheap plastic plant markers work very well and stay out of the way, so save your big and beautiful metal plant markers for the garden.

Keep your seeds moist and warm. Mist your seeds with water.

Assemble your pots in a seed tray (or reuse a disposable aluminum roasting pan, a baking pan, even that plastic clamshell that your salad greens came in) and cover with a humidity dome (or just plain old plastic wrap). If your dome has vents, keep them open to help with air circulation during the sprouting period.

Now, you need to add heat. Since sunlight is not essential at this point, your seed trays can be placed wherever it’s warmest in your house, such as an attic, bathroom, laundry room, or kitchen.

Within a couple of days to a couple of weeks, the seeds will germinate. Germination (the process of a seed sprouting) is highly variable, so don’t stress if it feels like it’s taking forever to happen. In most cases, seeds will germinate within three weeks (after that, try starting a new round of seeds).

Give your new seedlings light. At this stage, the newly germinated seedlings need light. Remove the humidity dome or plastic wrap, and move the seedlings to the sunniest
spot in your house (preferably a south-facing window).

Continue to keep the mix moist, but not overly wet. Seedlings should be watered once a day or every other day, depending on how much sun and heat they get. Remember that seedling roots are fairly close to the surface and they’re growing in a small amount of media, so they don’t need a deep soak the way larger plants do.

Moving day! Transplant the strongest seedlings when they're ready. After your seedlings develop their first “true set” of leaves, they are ready to be transplanted.

If more than one seed sprouted, choose the strongest one and pinch or snip off the others. You can even keep all of them, but be careful separating the roots if the seedlings are close together.

Transplant the seedling into a larger container filled with potting mix. Hold it by the cotyledons (the first leaves that appear) and try not to manhandle the tiny roots.

At this stage, you can lightly drench the potting mix using a diluted solution of compost tea or all-purpose fertilizer.

Harden off those seedlings. To get your seedling prepped for a good life outside, you can start to harden off the seedling by moving it outside under diffused light for a few hours and bringing it back inside each night.

Over the next week, move it from diffused sun to partial sun to full sun, and for longer periods of time, until it’s finally kept outside all night.

Transplant your seedlings outdoors. After the hardening off period, you can transplant your seedling to its final destination, whether straight into your garden or into a larger
container.

Did you make this project?

Please leave a comment on the blog or share a photo on Instagram

What to know after your seeds germinate

This post updated from an article that originally appeared on March 19, 2011.

View the Web Stories on how to start seeds indoors.

Seed Starting Lessons I Learned the Hard Way

Starting your own seeds can be intimidating for new gardeners, but once you get the hang of it, there’s nothing to fear. One of my goals here on the blogis to provide you with the best information, to help you grow great flowers and hopefullydispel the notion that success is only possible forprofessionals.

In addition to some of the tips I’m sharing today, I want to make sure you know about a coupleother sources of info here on the Floret site:

-In the Floret Resourcessection, I have created a little Starting Seeds 101 tutorial and photo essay (be sure to click the arrows to advancethe images) with some of the basics.

-Here on the blog, you’ll find a post covering Seed Starting Basics.

-In the Floret Shop,I’ve includedsowing and growinginstructions for dozens of my favorite flowers.

There’s nothing I hate more than seeing trays of beautiful little baby flowers go downhill before my eyes because I overwatered, underwatered, or got too excited about transplanting and didn’t properly harden them off. Seriously, I’ve found some pretty lame ways to waste expensive seed and lots of creative waystokill baby plants over the years. Learning the hard way isn’t the most fun way to start seeds, so hopefully you can avoid making these same mistakes.

I’ve put together a little list of some Do’s and Don’t when it comes to seed starting. This list of quick tipsis meant to complement other resources I’ve already created, plushelp you learn from some of my greatest seed starting blunders.

DO tamp downthe soil into your containers or cell packs. Then pack it down a teeny bitmore. By pressing down on the soil, you not only eliminate air pockets that little rootlets don’t like, but you also make it so mucheasier to remove your baby plantsonce they are ready to transplant. I remembermangling a whole mess of baby snapdragons because I had been sloppy about filling the flats with the soil. When it came time to transplant, instead of popping the plants out with a nice solid chunk of soil attached, the soil separated from the roots and I ended up with a crumbly mess and traumatized plants.

DON’Tforget tomoisten the seed starting mix prior to adding your seeds. If you add your seeds to dry potting mix and then try to overhead water, there’s a pretty good chance you’ll send your seeds floating to the corners of the container. If they are really tiny like Iceland poppies or snapdragons, you’ll probably wash them away and have to start over.

DON’T start your seeds too early.In the rush to get growing, it is easy to fall into the trap of startingall your seedsall at once. If you readthe seed packets or catalog descriptions, you’ll note thatit is recommended to start some slow-growing flowers earlier (10-12 weeks before your last frost) than others (4-6 weeks). If your frost-free date isn’t until mid-May, for example, you’ll want to start your foxglove now, but hold off on fast-growing, heat loving zinnias until later. One year I totally jumped the gunand planted zinnias waytoo soonand I had plants bustingout of their pots, becoming root bound because they had no where to go.They were ready to be transplanted outside, but thespring frosts hadn’tyet passed, so I had to throw them all away.

DO use bottom heat to get your seeds started.It is amazing how much faster and how much better seeds germinate with a little heat at their feet. Propagation matswork great forthis. If you are a home gardener or small scale flower farmer you can get by with just one or two mats. Leaveyour seed starting trays on the heat mat only untilthey germinate. Once sprouted, move thetray off the heat and make room for the next seed starting tray(s).

DON’T seedmore than one type of flower in the tray, especiallyif you plan to use a humidity dome. Germination rates vary by variety so it is best to have all the cells filled with the same flowers, that way you won’t be forced to remove the dome too soon for a row ofearly germinators ortoo latefor those slow to germinate. Plus, having variable plant heights in the same traymakesadjusting the height of the lights over the trays difficult (shorter plants within the tray can get leggy when light is adjusted for the taller plants).

DO remove the plastic humidity dome afteryour seeds germinate. Domes arereally only used on the traysuntil the seeds germinate, which for some varieties may be as few as a few days. Once your plants have popped up, they need lots of air and light. Left on too long, domes can kill seedlings. Note: some gardeners recommend“weaning” their trays from a humidity dome by propping the dome open for a day or two before fully removing it. Similar to the process of hardening off more mature plants, this gradual acclimation to the heat and humidity outside the dome can reduce plant shock.

DO water your plantsfrom the bottom when possible. Standard seed starting sets contain three pieces: a humidity dome, a cell pack layer withdrainage holes, and a tray that serves as a liner for the cell packs. By nesting yourcell packs (or whatever container you choose to use) in the waterproof tray, you can then add water to the tray which allows the soil to essentially siphon or wick up the water.This keeps water off of your leaves, helps prevent problems with fungus and disease, plus it focuses water where it is needed most, at the root level.

DON’T underestimate the amount of light tiny plants need to grow. If you use grow lights, be sure to adjust them so that they are no more than threeinches above the tops of your plants. When I wasa newbie, this was not intuitive to me. At all! As a result, I grew lots of gangly, leggy plants because theyweren’t getting enough light.The bulbswere simply too far away from the foliage canopy. Once I realized my mistake, I adjusted the lights to about an inch or so above the top of the leaves (it seems really close, but trust me this is better for the plant). Once I had the lights adjusted, I found that theplants grew so much better, with nice strong stems.

DO “harden off” your plants before you transplant them. I am embarrassed to admit just how many plants I fried because I didn’t do this key step. In my excitement to transplant my baby plants into the field, I didn’t give them any chance to acclimate to their new outside environment. “Hardening off” is simply a process of allowing your plants time to gradually adjust to their new environment.

Think about it: your little plants have been in a warm and cozy, temperature-controlled environment for weeks, or months. If you suddenly take them from that space and expose them to bright sun,wind and temperature swings inthe open garden, it is stressful to the plant. This stepoften requireslots of moving plants around, but trust me, transplant shock is real and deadly and taking the time and effort to allow your startsto adjust will make for happier, stronger plants and more flowers.

DON’T beat yourself up if you make mistakes. Unless you are super lucky or already have a magical green thumb, you’re probably going to make a few mistakes your first time time starting seeds. $#!+ happens. And it’s ok! You’re sure to make far fewer mistakes than I did during the early days, but just know that goofing up is inevitable. That is part of the joy in gardening is learning what systems work well for your situation, your climate.

Have you made any of these same mistakes? Or do you have anyseed starting lessons you learned the hard way? I’d love to hear about them in the comments below.