The Best Indoor Seed Starting Supplies & Equipment

For beginners, I highly recommend using commercial trays like this one, rather than experimenting with other types of containers. These are the basic ones that I use year after year, and can't live without.

If you prefer using pellets, then you need this kit. It comes with everything you need. All you have to do is add water, and you're ready to start planting. The tray is reusable, so you only need to buy pellet refills each year.

You can also get a more complete kit, like this one that comes with a grow light, and a nice high dome with plenty of room for seedlings. You can use this one with either pellets or plastic cells, whichever you prefer.

On the other hand, if you don't need lights, then this kit comes with a heat mat instead. Bottom heat helps to speed up germination, and it’s a huge benefit to have one of these.

In my experience, the plastic trays wear out faster than the cells and lids. Don't worry, you don't have to buy a whole new kit, you can buy these replacement trays instead. It's also nice to have extras on hand, just in case one of yours springs a leak.

The plastic cells that come inside the tray last a long time, and can be reused for years. But sometimes you give them away, they get lost, or they break (or get stepped on - oops!). So it's good to know the replacements are fairly inexpensive.

Of course, there will also come a time when you need new lids. They will usually last the longest, since you don't need to use them for very long. But, if yours need to be replaced, this is the standard size.

It is very important to use a high quality mix that is specifically made for growing seeds, like this one. Don't try to use inexpensive dirt or general purpose potting soil. Trust me, this is the one thing you do not want to go cheap on.

Plantable pellets are a great alternative to soil. They're simple to use, with less mess. Plus, they can help reduce transplant shock, since they can be planted right into the ground. This is the standard size.

The standard pellets are great for most seeds, but can be too small for some. These bigger pellets will expand up to 3.5 inches, which is perfect for larger seeds, giving them plenty of room to grow.

This naturally occurring mineral helps to keep the potting mix evenly moist, improve drainage, and prevent compaction.

A lightweight amendment, perlite retains very little moisture, and prevents compaction. In other words, it helps the water drain faster, which is exactly what we want for seed starting.

This additive helps the soil retain moisture longer, and also feeds the seedlings as it breaks down. It is slightly acidic though, so you'll need to add some garden lime if you use it.

As the by-product of coconut processing, coir is a more sustainable alternative to peat. It also holds moisture, and adds nutrients to the soil as it breaks down. Plus it’s non-acidic, so no additional additives are required.

If you choose to use peat moss in your potting medium, then you'll need to add some lime to neutralize the acidity.

This super-slim fixture includes a full-spectrum T5 lamp, built-in timer, and hanging hardware. The width is just right for hanging on shelves, or inside of a mini indoor greenhouse.

If you're looking for a larger light fixture, this one is the same as the one above, only a few inches longer. It also includes the T5 bulb, hanging hardware, and built-in timer.

For those of you looking for a more complete system, this is a great one. It's 2 feet wide, which is perfect for a couple of flats. Plus it's very easy to adjust the height of the light, and you don’t need any other special equipment to use it.

Want an even larger seed starting system? This 4 foot grow light system has all the same features as the one above, but you can fit more trays underneath it.

If you want to make it simple to move your lights up as the seedlings get taller, you need to get these adjustable hangers. They’re not required, but certainly make life much easier.

When you plug your lights into a timer like this one, you can just set it and forget it! This is by far the best way to ensure your seedlings get enough light, and on the same schedule every day.

It's important to feed seedlings with a gentle fertilizer to avoid burning or damaging the delicate baby plants. This one is specifically made for safely feeding your starts.

Compost tea is a very good and gentle natural fertilizer. This one comes in a concentrate. So you can make it weaker for brand new starts, then increase the strength as the seedlings get bigger. If you prefer, you could buy tea bags to brew your own.

This is another great one that is specifically made for seeds and seedlings. It's granular rather than liquid, so you can add it to the soil, or pour it into the hole at planting time.

Another great fertilizer that comes in a liquid concentrate, and trust me, seedlings love fish emulsion. Though you certainly could use this indoors, you might want to save this one for outside, because it can be a little stinky.

Using plantable pots makes it easy to plant seedlings into the garden, and lessens the risk of transplant shock. This is the 4" size, but the 3" ones are also great for potting up your starts.

If you're worried about the sustainability of peat, then coco coir plantable pots are the solution. This is the 3" size, or the 2" size for your smaller seedlings.

If you want something that's reusable, then I recommend getting a nice set of plastic nursery pots. These will last for many years, are easy to clean, and they don't take up much space in storage.

This size is my favorite to use inside of my trays because they fit underneath the standard height lids. They are also reusable, so make sure to keep them for next year.

These longer plant tags are nice to use once you pot up your seedlings, or if you have a higher dome lid on your trays. You can also use them in the garden.

If you don’t want to take the time to write on all of your tags, color code them instead! This way, you can just use one color for every type of seed, and keep a reusable chart so you know what’s what.

Adding bottom heat under your trays will speed up germination, and also keep your seedlings toasty warm. A heat mat is definitely a must for seasoned growers.

Humidity is very important for germination, and misting your seedlings is a great way to give them the moisture they need to stay healthy. This spray bottle is also good for watering those tiny starts.

If you don't want to bother with spraying water, use a humidifier instead. Heating your house during the winter sucks the humidity out of the air, and your seedlings will be much happier with the consistently added moisture.

With this inexpensive monitor, you'll be able to keep track of both the humidity level and the temperature indoors. That way, you can easily make any necessary adjustments to keep your seedlings thriving.

Inconsistent watering is the number one cause of seedling death, and it can be difficult to get it just right. So, if you struggle with watering, I highly recommend getting one of these. 

This potting tray contains the mess indoors, and I love it for filling my trays, or potting my seedlings. It's portable too, so you could even use it for transporting your starts, or moving them outside.

Once you have one of these, you'll wonder how you ever lived without it. You can fit two trays on each shelf, and hang the lights right over the top. The plastic cover is easy to vent or remove, and allows you to control both the humidity and temperature.

This cute garden themed wooden box is nice for organizing leftover packets, so they are ready to go when it comes time for planting next year. It's made of cedar, which also helps to keep them fresh longer.

You can use a recipe box to store your packets alphabetically. They fit perfectly into a standard sized recipe box. This one is both nice looking and durable.

This binder is specifically made for keeping seed packets nice and organized. It would fit well on a bookshelf, and even has pages where you can write down details of each packet for tracking purposes.

I prefer to put my leftovers in a clear plastic shoe box. I like these because they stack neatly, and fit on the shelf in my basement closet. I can also fit larger envelopes or baggies into these, not just the regular sized packets.

These small envelopes are the perfect size for leftover seeds. Use them if you lost the original packet, or for sharing your extras with friends. They're also nice for giving as gifts.