5 Must-Have Items in My Seed Starting Kit

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.

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.

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.

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…

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.

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.)

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.

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

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 mat, and a couple of small fans.

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.

But after I moved to Central Oregon and set up my seed starting station in a cold garage, this heat mat made noticeable improvement in germination rates and times for heat-loving crops like peppers and tomatoes.

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).

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

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.