Staring your own seeds indoors isn’t just a massive money-saver, it’s also an incredibly rewarding experience. You just have to make sure you have all the right products, tools, and equipment. Especially if you’re planning to start different types of seeds indoors at the same time.
Yet there are a lot of strange gadgets and unnecessary gardening devices out there that over-promise, under-deliver, and can take a big bite out of your budget.
Don’t worry, we’ll break it all down, to help you find the must-have products you need to start all your seeds indoors.
Seedling Heat Mat
https://www.amazon.com/BN-LINK-Durable-Seedling-Hydroponic-Waterproof/dp/B08NB4PX9Y/
A good heat mat is an absolute must-have item when starting your seeds indoors. Providing a constant and consistent heat source under the planting trays helps boost germination rate and time.
Especially for heat-loving plants like tomatoes, peppers, and eggplants. Some pepper seeds can take up to four weeks to germinate in room temperature soil but will germinate in just 5 to 7 days in soil consistently heated to 75 degrees Fahrenheit.
What to Look for in a Seedling Heat Mat
A good heat mat for starting seeds indoors should be around 10” X 20” which will fit most germination trays. You want one that’s rated to heat 70 to 85 degrees and consumes around 18 to 25 Watts. Waterproofing is an absolute must-have feature as the mat will occasionally get wet.
Pro Tip
Once the seeds germinate, you want to take them off the heat within the first 24 to 48 hours. Excess heat can cause seedlings to grow too tall and too fast. They can become “Leggy” to the point that they fall over and die if left too long in warm soil.
Germination Tray
https://www.amazon.com/Gardzen-Propagator-200-Cell-Starter-40-Cell/dp/B07R9S38VX/?th=1
You need a germination tray to keep your seedling plugs or peat pots warm and moist. It also keeps random bits of soil contained, without spreading all over your counter or gardening bench.
They’re made from plastics that can transfer the warmth of the heat mat to the seedlings without melting or degrading. The clear plastic lid lets you trap moisture to keep the peat or seed starter potting soil from drying out.
Sometimes you can even find germination trays with peat plugs included in the purchase. The tray is reusable. I have some that are ten years old! You can then buy replacement peat plugs year after year for cheap.
What to Look for in a Germination Tray
https://www.amazon.com/Gardzen-Propagator-200-Cell-Starter-40-Cell/dp/B0BNPKXRY1/?th=1
A good germination tray needs to be tall enough to let the seedlings sprout without hitting the top of the clear plastic dome. Some will even have damper wheels on the top to let you release just the right amount of humidity. These are nice but aren’t 100% necessary.
Seedling Peat Plugs
https://www.amazon.com/ZeeDix-Pellet-Fiber-Plant-Starters/dp/B0BJ1XSN2S/?th=1
Seedling peat plugs are a must-have planting medium for germination trays that have a perforated base. Each plug will fit perfectly into its spot and is easy to remove when the seedlings emerge. This strategy makes the most out of every square inch of your seedling trays, which comes in handy if you need to start a lot of seeds indoors at the same time.
How to Use
You just soak the dried peat plug in warm water for 3 to 5 minutes. Once it expands you insert it into place in the germination tray and bury a seed in it.
What to Look for in Seedling Peat Plugs
Peat plugs are pretty much the same from one vendor to the next, but you need to decide whether you want them in mesh or not.
The benefit of mesh is that the plug is easier to handle, and you get less debris sitting in the bottom of the germination tray. It might also cost you another $1 for a box of 72.
The problem with mesh-encased peat plugs is that they’ll remain with the seedling and will eventually transplant into the garden. While the roots will easily grow through the mesh, it can take more than a year to fully biodegrade.
Seedling peat plugs without mesh can be messy and can leave peat in the germination tray. Sometimes the bottom of the plug will get stuck in the tray splitting the plug when you lift it out. So, you have to be careful, and you need to clean the germination tray thoroughly after every use.
Peat Pots
https://www.amazon.com/GROWNEER-12-Pack-Biodegradable-Seedling-Germination/dp/B07KWWQNHR/?th=1
Peat pots are better for starting squash seeds, cucumbers, and other seeds with sensitive roots. Squash and similar large seeds can be prone to transplant shock if they’re started in a peat plug and directly transplanted into cool soil beds.
Peat pots also give the roots more space to develop. If you’re only starting a small number of plants, you can grow just about any type of seed in the cells for weeks. It can come in handy if the spring weather outside is fickle or there’s a cold snap in the extended forecast.
The other nice thing about peat pots is that the roots will grow through them, and they will biodegrade into neutral soil for two to three weeks after transplanting into the garden.
How to Use
You simply fill each peat pot cell with loose potting soil or seedling starter mix leaving roughly an inch of headroom at the top. Lightly water the soil to absorb the moisture. Then insert the entire tray of cells into your heated germination tray.
You can then lay your seeds on top of the damp potting soil, and lightly cover them. Place the lid on top and let the peat pots warm.
Pro Tip
If the shape or the height of your peat pots makes it hard to completely seal the lid on your germination tray, you can lay a hand towel over top. This is better than using duct tape, and as long as the hand towel covers the lip of the lid completely, it will hold all the necessary heat close to the peat pot cells.
What To Look for in Seedling Peat Pots
When choosing the best seedling peat pots, you want to consider the internal dimensions of your germination tray. Not all peat pot makers think about this detail, and a set of squares will make better use of your space than round peat pots.
For squash plants, pumpkins, and cucumbers that spread out a large root base shortly after germinating, you want each cell to be at least 2 to 3 inches tall and 2 inches square.
Grow Lights
Even if you have a bright sunny window with full southern exposure, you still need a good grow light to start seeds indoors. Especially if you are growing “Short Day” plants like peppers and tomatoes that respond to the changes in day length.
If you start these seeds indoors in just a sunny window, they will linger and might suffer stunted growth with the short days of late winter and early spring. A grow light lets you set their day length to 12+ hours and ensures they get the light they need for growth and vigorous photosynthesis, without worrying about cloudy days!
What to Look for in Grow Lights
There’s a staggering spectrum of grow lights you can use to start seeds indoors to match any budget. The type that’s best for you will depend on your setup and just how much natural light your seedlings will get.
This is the sort of topic that deserves its own deep dive. The best we can do in this article is give you some quick highlights.
Fluorescent Grow Lights
https://www.amazon.com/Sylvania-24755-DAYLIGHT-SPECTRUM-Fluorescent/dp/B07CVJZCP9/
Fluorescent grow lights are by far the most budget-friendly way to provide your indoor seedlings with the light they need to grow. You can get a standard 48-inch, 2-bulb fluorescent light fixture “Shop Light” and install two 40-watt fluorescent bulbs in it. Just make sure they’re “Full Spectrum Daylight” fluorescent bulbs.
These fixtures usually come with a cheap chain that lets you suspend the grow light 3 to 4 inches above the seedlings.
This setup is best for indoor seedlings with a nice south-facing sunny window supplying light through much of the day. The fluorescent grow lights augment the natural light in the morning, late afternoon, and on cloudy days.
Seedlings grown exclusively under fluorescent grow lights are prone to becomingleggy anddevelop purple colors under the leaf’s indicative of low soil phosphorus.
LED Grow Lights
https://www.amazon.com/Soligt-Starting-Spectrum-Seedling-Adjustable/dp/B0BLRXV6HP/
LED grow lights cost more, but their output and lifespan provide you with a good return on your investment. They’re available in a wide range of sizes and configurations that lets you customize the grow light fixtures to your set up.
For starting seeds indoors, you want LED grow lights that are full spectrum or blue spectrum daylight. This promotes photosynthesis which young seedlings need to grow vigorously. Avoid red spectrum grow lights.
LED grow lights are a good option if you have limited natural light for your indoor seedlings. The seedlings will grow just fine for several weeks or even months if you exclusively use LED grow lights.
High-Intensity Discharge Grow Lights
https://www.amazon.com/PROTOPIA-MH400WT46-36000Lumens-Commercial-Applications/dp/B071Y2V4Q3/?th=1
High-Intensity Discharge (HID) grow lights use either metal halide or high-pressure sodium bulbs to create an intense light that promotes rapid seedling growth. They’re the best option for growing seedlings indoors in a setup where there’s little to no natural light.
There are some drawbacks to HID grow lights that you need to be mindful of. They tend to be the most expensive option yet have a lifespan shorter than LED grow lights. HID fixtures tend to produce more heat. If you don’t have a cooling system, there’s a possible fire risk, and any seedlings that bolt accidentally can suffer damaged leaves as they grow toward the HID bulbs.
Seed Starter Potting Soil
https://www.amazon.com/Espoma-Organic-Starter-Premium-Potting/dp/B01N38GBTM/
If you’re starting your seeds indoors in peat pots, you need to use seed starter potting soil to get the best results. You can also use this potting soil for growing small seedlings started in peat plugs.
Seed starter potting soil is formulated with the right balance of nutrients to promote root growth and photosynthesis, which indoor seedlings need to thrive. It also does a good job of retaining moisture to ensure your tender seedlings don’t accidentally dry out.
Conclusion
To start seeds indoors you need a heat mat with a germination tray to keep soil and seeds warm throughout the germination process. You also need a soil medium such as expandable peat plugs, or peat pots filled with seed starter potting soil.
When it comes to choosing the best grow lights for starting indoor seedlings, you need to consider both your budget and the available natural light. If your budget is sparse, but you have a window with a reasonable amount of south-facing light, you can get away with full spectrum daylight fluorescent grow lights. If you’ve got a slightly larger budget LED grow lights will give you a better long-term return on investment, and you’ll.
Written By
Amber Noyes
Amber Noyes was born and raised in a suburban California town, San Mateo. She holds a master’s degree in horticulture from the University of California as well as a BS in Biology from the University of San Francisco. With experience working on an organic farm, water conservation research, farmers’ markets, and plant nursery, she understands what makes plants thrive and how we can better understand the connection between microclimate and plant health. When she’s not on the land, Amber loves informing people of new ideas/things related to gardening, especially organic gardening, houseplants, and growing plants in a small space.