5 Must-Have Items in My Seed Starting Kit

You can certainly get started inexpensively with random pots and trays in front of a window. But if you want to up your seed starting game, improve germination, and grow strong, healthy seedlings, it pays to invest in quality seed starting supplies and equipment. These are the exact items I use at home, and many of them I’ve used for many years—they’re what I consider crucial for seed starting success.

Linda Ly
Close-up of mustard seedlings growing in a seed starting tray

I get a lot of questions about seed starting supplies, and before I get into this guide, I want to make clear:

You absolutely do not need to spend a fortune on seed starting supplies.

I’ve previously written posts on scoring cheap seed starting supplies at the dollar store (in other aisles besides the gardening aisle!) and also where you can find free seed starting containers. I’ve even started seeds in eggshells and made newspaper pots to sow seeds in.

So you have a lot of options if you’d rather spend your money on seeds and soil mixes (which is where I’d personally focus my budget if I was just starting out again).

That said, there are definitely benefits to buying HIGH-QUALITY seed starting supplies that will last for many years. If you can invest in a few key pieces each year, they’ll pay for themselves over and over because:

  1. Uniform sizes and shapes make stacking and storage much easier.
  2. Trays and inserts use space more efficiently.
  3. Trays and inserts keep you better organized as you can sow seeds in rows and groups.
  4. You save money (and frustration) by not having to replace broken pots and trays every couple years.

This list doesn’t include my entire indoor seed starting setup (which I’ll cover in a separate post). I just cover the items that I feel are essential to get started, and because I’ve been using most of these items for years, I can vouch for how long they’ve lasted and how much I’ve relied on them.

Further down below, I also recommend a few of my favorite seed starting tools that you don’t necessarily need, but they will make things much easier!

Disclosure: If you shop from my article or make a purchase through one of my links, I may receive commissions on some of the products I recommend.

The best seed starting trays

Who’s got the best seed starting trays? Hands down, Bootstrap Farmer.

They make the most durable trays ever that don’t bend or sag like other brands do. I’ve been using the same trays for more than seven years and there’s not a crack or dent in them. (Which is saying a lot, as I’m pretty rough on my tools and also had toddlers during that time who love to “help” in the garden.) They also come in multiple fun colors besides black, and that’s a little bonus that makes me so happy every time I see them!

The industry standard is a 1020 tray, which I think makes the best use of space. It’s called a 1020 tray because it’s 10×20 inches in size, so 1020 trays from different brands should all nest inside each other, but buying trays made by the same company will ensure they do.

Flat trays

Let’s start with these flat trays, which are designed to hold various inserts and pots. This is one of the pieces that tends to get the most hammered over a season, so it pays to get the best-quality tray you can.

Bootstrap Farmer

Flat trays

Pair these 1020 shallow trays with cell trays to bottom water your seedlings more effectively.

I prefer the shallow version without holes, which fits all my Bootstrap Farmer inserts perfectly. It also makes it very easy to bottom water seedlings. I also have a set of the deeper trays that I use to carry other pots outside for hardening off transplants, to hold random tools and seed packets, things like that.

Cell trays

I use these 32-cell seed starter trays with inserts, which I find to be a very flexible system. The bottom tray is where I usually start my seeds. Each cell is 2 inches square and 2 inches deep. If I need to pot up seedlings, I use the included pots (3 inches deep) which nest neatly inside the tray.

Bootstrap Farmer

32-cell trays with pots

The larger cells and included pots make for a very flexible system for seed starting.

If I know my seedlings will be staying in pots for a while, I’ll start seeds right in those pots (instead of in the bottom tray). This set gives me a few options depending on what I’m growing each season, and I like that I can use one or both pieces together or separately.

A big question here is: How many cells do you want per tray?

If you’re starting thousands of seeds or have a smaller space, you might go with their 128-cell or 72-cell inserts instead. The cells are much smaller (about 1 inch square) but they’re more efficient if you tend to transplant seedlings soon after the first true leaves appear.

However, there’s another product I love if you want to go that route…

Air pruning trays

I’ve only been using these air pruning trays for a year-and-a-half, but wow! My indoor-grown seedlings in my northern climate get quite robust in these.

Bootstrap Farmer

72-cell air pruning trays

Special air strips promote greater air flow for healthier root systems and stronger seedlings.

Bootstrap Farmer calls this an alternative to soil blocking, as it offers all the same benefits of healthier root systems and stronger transplants without the mess.

The trays have special air strips in each cell that “air prune” the roots to prevent root circling. (It’s the same principle as grow bags, which I also love using.) The large holes on the bottom make it simple to pop a seedling out without disturbing it too much. (And no, soil won’t fall through those holes when you fill the tray—I was skeptical too, until I started using it.)

You can use the same seed starting mix you always use and set it inside a 1020 shallow tray for bottom watering.

Do you need both types of cell trays?

I personally like having options, and I feel the 32-cell trays and 72-cell air pruning trays offer enough versatility that I don’t need to buy a bunch of other trays and pots for my seed starting.

If you’re unsure of how many you need, let’s say you’re only sowing 5 to 10 seeds of each variety of plant, and you’re growing 10 different vegetables. So you’re starting 50 to 100 cells. (I say cells instead of seeds here, because you might sow a couple of seeds per cell to ensure germination.)

In this scenario, I would suggest buying two trays—a 32-cell and a 72-cell, or two of the 50-cell. This way you can plant one tray with seeds that’ll grow faster or have similar days to maturity, and plant the other tray with slower-growing vegetables. It makes your seedlings much easier to manage.

The best seed starting mix

If you’ve read my other post about making your own seed starting mix, then you know my opinion that this is the best way to go, particularly if you’re starting lots of seeds. It doesn’t take much more effort than using premade mix, and you’ll save some money too.

You only need three ingredients: peat moss (or coco coir), perlite, and vermiculite.

If you prefer to buy something off the shelf, here’s a high-quality bagged mix that I’ve used in my daughter’s school garden. (I also like that it comes in a decent-sized bag for the average home gardener.)

Espoma

Organic seed starter

This 16-quart bag of seed starting mix is more than enough to start an entire season’s worth of seeds at home.

The best affordable grow lights

You’ll find many opinions on what the best grow lights for plants are, and this is mine: For casual seed starting, you don’t need anything fancy. Even shop lights will do.

But if you want a reliable, energy-efficient, powerful grow light that will last years, go with these full-spectrum LED lights. These are the exact grow lights I use at home, and at the time of writing (January 2025), I think they’re the best bang for the buck.

Barrina

Full-spectrum T8 LED grow lights

For casual seed starting, these affordable yet powerful lights will help you raise strong seedlings.

They’re also super simple to use (just plug in and go!) and you can attach them (with adjustable zip ties or chains) to any shelving unit you’re using for seed starting. You can also daisy chain multiple Barrina lights quite easily.

Other tools I love

Timer

An outlet timer is optional, but let’s be honest, most of us are way too busy to remember to turn the lights on and off every day. (Before I had a timer, I found that I would just turn the lights on and off on my schedule, so my seedlings weren’t getting the full 16 hours recommended for strong growth.)

A simple manual or digital outlet timer is all you need, but I personally use this multi-outlet surge protector timer so I can plug in my lights, my heat mats, and a couple of small fans.

BN-Link

Surge protector digital timer

A multi-outlet timer lets you plug in all your lights, fans, and heat mat while ensuring your seedlings get 16 hours of light per day.

Mini fan

Speaking of fans, I added these portable clip-on fans to my seed starting setup a couple years ago and I regret not getting them sooner!

Comfort Zone

Mini clip-on fan

Run these portable 6-inch fans for a couple hours each day to prevent damping off disease and strengthen seedlings.

If you’ve read my guide to hardening off plants, I recommend lightly brushing the tops of your seedlings with your hands to simulate a breeze and help them grow stronger stems. You can totally still do that, as it’s free and you’re likely checking on your seedlings every day anyway.

But running small fans for a couple hours a day has really upped my game, as they’ve reduced the chances of damping off disease to pretty much zero and provide crucial air flow once all my seedlings grow in thicker.

Heat mat

I’ll start off by saying this item is not essential. I started seeds indoors for many years without a heat mat, and they came up just fine.

But after I moved to Central Oregon and set up my seed starting station in the garage (where it often never got above 60°F in early spring), I noticed heat-loving crops like peppers and tomatoes would take much longer to germinate. Combined with a humidity dome (below), this heat mat made all the difference in improving my germination rates and times by at least a week!

BN-Link

10×20 heat mat

This heat mat fits perfectly under your seed starting tray to gently heat the soil and encourage germination. In cold spaces, it also helps warm up the air around your seedlings.

You only need one mat, but this two-pack is a great deal. Once your seeds germinate, you can move the mat to another tray as needed or keep it under your seedlings to help warm up the ambient room temperature (if you’re starting seeds near a drafty window or in a cooler part of your home, for instance).

Humidity domes

I use humidity domes over my trays immediately after sowing seeds to keep in heat and moisture. For most of the cool-season crops I start in my garage, this dome is enough to warm them up and they don’t need a heat mat for germination. (And if your seed starting station is inside your house, it’s probably all you need as well.)

Bootstrap Farmer

Humidity domes

Use a humidity dome right after you sow seeds to help keep heat and moisture in for faster and more consistent germination.

The 3-inch domes are my favorite height since they’re less bulky.

Seed planting trowels

I started out using this adorable spoon-sized trowel from Gardener’s Supply, which comes in much handier than you might think. It makes quick work of releasing seedlings from cell trays and I also use it when repotting houseplants. Much more effective than a regular spoon, which was my prior tool for the job.

Gardener’s Supply Company

Mini trowel

Who knew a spoon-sized trowel could be so useful?! This is the perfect size for repotting seedlings and making narrow trenches in soil.

Recently, I purchased this seed planting trowel from Fiskars and I like it even more! It combines multiple tools into one (a mini trowel, a widger, and a dibber) and cleans up very easily.

Fiskars

Seed planting trowel

This handy tool is actually multiple tools in one: a mini trowel with measurement marks, a widger, and a dibber.

4 Comments

  1. In the early 1970’s, I started slow germinating seeds, particularly celery, in undivided flats. After seeding, I placed them in plastic bags to retain moisture. I didn’t know any better, but theoretically they should have been surface sown to enable light which they require for germination. I don’t know why they germinated in the dark cellar, only dimly lighted by small casement windows, but they did. I’d pay more attention to lighting now. (I’ve since managed organic greenhouses that grew out thousands of seedlings in late-winter, early spring. (If you are interested in production, a cold frame is invaluable.) I started tomatoes in February in whatever salvaged container I could get. Of course they got leggy. This was an advantage as I later transplanted them in tall cardboard milk ‘boxes’ with just the top leaves showing. I set these in a south-facing sun porch, uninsulated and with leaky louvered windows. Somehow that worked. They got leggy again, but not so much. Using the same system Linda has decribed in an earlier post, I made furrows as deep as possible with the plow attachment on my Troy-Bilt tiller using roughly 3′ between rows. Then I set poles in the furrows while my two pre-kindergarten daughters remove the plants from the milk cartons and lay them in furrows, so only 3 or 4″ of tops remained to be tied to the trellis poles as they grew. We transplanted 6 dozen in an hour or two. I also used a pruning system that didn’t remove early suckers but let them produce two sets of blossoms before snipping the tips. I stopped permitting new suckers in early August and by mid August I clipped all growing tips. Nominal first frost was Aug. 20, but we could get a frost any month. When when a hard frost was predicted, I picked all remaining fruit, usually 3-5 large garbage pails full, dollied them indoors, and went through them about weekly, sorting by ripening stage and chucking spoilage to the chickens. (Tomato seed is high in lysine, which chickens need especially.) We ended up with dozens of quart jars ‘canned’ and nearly 10 gallons of tomato juice, mainly from the green fruit that ripened indoors. (I bought an estimated 5% of our food, with the rest home grown and foraged. I probably grew twice as much as we needed of each crop, in case of crop failure, with the surplus bartered or sold at farmers market. That brought in far more cash than we spent in the grocery store.)

  2. Thank you for all these tips. Do you ever use an AeroGarden or like hydroponic garden and if so, any tips? TY

    1. Hi Martha and Linda!

      Follow the Aerogarden instructions and you’ll be fine. Lettuces are very easy to grow hydroponically but you can only harvest a few leaves from each plant every day or two. Herbs take twice as long to get to a usable height, but are awesome growing in the kitchen once mature enough for regular harvesting. (This is what I recommend growing.) Tomatoes are the most difficult because they take awhile AND you have to hand pollinate the flowers for the fruit to develop. Linda has a great article on Garden Betty about hand pollinating squash that describes the process.
      Some produce departments sell fresh hydroponic herbs with roots that you might be able to add to the aerogarden, for instant gratification.

      Pay attention to the water/ nutient level, larger plants consume more during growth spurts. If the plants start looking droopy, empty all the water and refill it with fresh hydroponic water. A little direct sunlight would help them grow faster, too.
      Good luck!

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