Q&A: What equipment do I need to start seeds indoors?
This question comes from our client Michael in Nolensville. We’re always inspired by his drive to up-level his gardening skills and excited for his foray into indoor seed starting. I’m sure he’ll teach us a thing or two after this season. I started to text him a list and quickly realized the length was becoming unwieldy. Plus, we need pictures, descriptions, and links to products! Let’s make this a useful resource for anyone who wants to dip a toe in — or jump into the deep end of the seed starting adventure.
As with any hobby or activity, the list of things you '“need” can quickly become quite long. Because we all have different budgets and “clutter thresholds,” I’ve broken this list down into the Essentials and the Extras.
Section 1 includes things that really are necessary for healthy plant development. Skipping these items will significantly impact your success. I tried to offer a free/substitute/make-do option where I can.
Section 2 includes things that make the whole process just a little easier, tidier, more beautiful, or more fun.
If even the essential list seems like too much investment, you might want to explore the Winter Sowing Method which requires much less equipment.
This article doesn’t go into the step-by-step of how to start seeds indoors, we’ll tackle that later. For now, get your supplies gathered and identify a space in your home that will be your new nursery.
Let’s go!
Essentials
These are the must-have items for seed starting. They provide the basic structure and support your seeds need to germinate and grow into healthy seedlings.
1. Grow Lights
Seedlings require bright, consistent light to grow strong. Regular indoor light usually isn’t enough—even south-facing sunny windows probably won’t cut it—so grow lights are a game changer.
Why? Without adequate light, seedlings become leggy (too tall) and weak.
Options: Whether you choose LED (energy-efficient, adjustable brightness, and low heat output) or fluorescent (affordable and effective, though they use more energy than LEDs) bulbs, they will need to hang directly above your seedlings. You can accomplish this by setting up a shelving unit, or by buying an all-in-one system, many of which are stackable if you want to expand your set-up in future years.
Gardeners Supply offers a wide selection of sizes, aesthetics, and prices.
Gardener's Supply Company Agie LED Grow Light Plant Stand with Wheels
2. Seed Trays and Cell Packs
These are the small containers you will fill with growing medium. Cell packs allow for individual seedlings to grow without overcrowding. They need drainage holes and a tray beneath them to catch water. You can buy various sizes, but generally a 1”-2” diameter on each cell will work for most seedlings.
Why? Keeps seedlings organized and makes transplanting easier.
Options:
Reusable Trays: Invest in sturdy, heavy duty re-usable trays that you can use season after season.
Favorites: Gardeners Supply Self Watering Seeds Trays (plastic, comes with a dome), or Self Watering Galvanized Seeds Trays (so easy to remove seedlings from these).
Skip: the cheap, flimsy seeds trays easily found at big box stores. This plastic is so thin, you will likely spring a leak before you can use it a second time. Truly disposable. 😩
Soil Blocks: An eco-friendly option—skip the plastic and press soil directly into blocks. You’ll need a soil blocker tool for this along with a shallow tray to set them on.
DIY: Reuse cell packs you got from the nursery when buying seedlings last season. Wash and disinfect them with a diluted 5% bleach solution. Set them on a serving platter you never use and don’t mind getting dirty.
Gardener's Supply Company Self-Watering Galvanized Steel Seed Starting Tray
3. Domes or Saran Wrap
Domes (or makeshift covers like plastic wrap) help maintain moisture and warmth during germination.
Why? Seeds need consistent humidity to sprout, and covers create a mini greenhouse effect.
Options:
Plastic Domes: Available to fit most standard trays. It’s fairly easy to find seeds trays packaged as a kit with a dome included.
DIY: Plastic wrap works in a pinch—just poke a few holes for ventilation.
4. Heat Mats
Heat mats warm the soil, providing the consistent temperatures many seeds need to germinate.
Why? Simulate spring by gently warming the soil to the temperature needed to spark seed germination.
Options:
Basic Heat Mats: Affordable, with no temperature control.
Adjustable Heat Mats: Include thermostats for precise temperature regulation. Vivosun Heat Mat, Thermostat Combo
5. Fan or Heater
Good air circulation prevents mold and strengthens seedlings.
Why? A gentle fan simulates outdoor breezes, encouraging stronger stems.
Options:
Desk Fans: Affordable and easy to position.
Heaters with Fans: Useful in colder rooms to maintain consistent temperatures.
6. Spray Bottle
A spray bottle allows you to water seedlings gently without washing away soil or damaging tiny sprouts.
Why? Seedlings are delicate, and heavy watering can dislodge them.
Options:
Any basic spray bottle works well.
My favorite: a pump sprayer saves me from getting hand cramps.
7. Seed Starting Mix
Unlike garden soil, seed starting mix is light, fluffy, and sterile.
Why? Provides the ideal texture for seed germination and reduces the risk of disease.
Options:
Pre-made Mix: Espoma Organic is a good one.
DIY: Mix your own with peat moss or coco coir, perlite, and vermiculite.
Don’t: Just scoop out soil from your garden. It will most likely be too dense for seeds to germinate and will have creepy crawlies you probably don’t want to bring inside.
8. Seeds
Choose seeds suited to your climate and gardening goals.
Why? The right seeds ensure a productive garden.
Options:
Check out the full article on seed shopping.
9. Fertilizer
Seedlings need nutrients once their first true leaves appear.
Why? Your potting mix doesn’t include any nutrients. Using fertilizer boosts growth and helps seedlings develop strong roots before they move into your compost-rich garden.
Options:
Liquid Fertilizer: When fertilizing seedlings, use at half the strength recommended for houseplants. Diluted fish emulsion or seaweed extract or Grow from Epsoma are good options.
10. Tags and Labels
Labels keep track of what you’re growing and where.
Why? Prevents confusion between similar seedlings. Ask me how I know!
Options:
Nice-to-Have Extras
These tools aren’t essential but can make the seed-starting process more efficient, enjoyable, and tidy.
1. Vermiculite
A light, moisture-retaining material to sprinkle over seeds after planting.
Why? Helps retain moisture and prevents fungal issues.
2. Tidy Tray
A large, shallow tray for mixing soil or catching spilled dirt.
Why? Keeps your workspace clean and organized.
3. Seed Cell Tool Kit
These adorable kits often include a dibber (for poking holes), tamper (for flattening soil), and a tiny trowel.
Why? Makes planting seeds precise and easy.
4. Gnat Control
Why? Fungus gnats thrive in moist seed-starting environments.
Options (you might need both):
Mosquito bits: Kill the larvae in the soil. Add them to your watering can (at rate directed on the container) once a week if you have issues with gnats. I call it “Mosquito Bits Monday” which nicely complements “Fertilizer Friday.”
Sticky traps: catch adult fungus gnats.
