There are so many ways to outfit a seed starting set up, and there is no ONE right way. There are ways to spend very little money, but the one thing I think is most important is the lighting. Can you start seeds in a sunny window? Yes. Are the chances that they will become leggy while reaching towards the light super high? Also yes.
I have spent many years figuring out what works best for me (it may be different for you) and what are the least expensive, but quality options.
You do not have to spend a ton of money. You could repurpose plastic containers (making sure to add drainage holes) with lids as your seed starting containers. I have done this, and it has worked just fine. If you don't purchase lights maybe you have a light that is a gooseneck or is positionable so that you can position it directly over your seedlings. Having the light right on top of them (not touching) is key to avoid legginess.
The first piece of equipment I purchased was a 5 shelf 4 foot wide metal shelf from Target. At the time of this post, the rack costs $80. You will see much pricier versions at home improvement stores, but this metal rack works fantastic. I prefer the metal racks because you can easily hang lights from the metal bars. You can also decide the heights between the shelves so you could make one taller than the others for plants that get big before planting out.
Now on to lighting. I do not buy into fancy "grow" lights. I use LED shop lights from Lowes. The ones I show here are linkable so you end up with just one plug at the end and they come with the light bulbs.
I prefer shop lights because I can have the lights right above the seedlings without worry of burning them. Some of the fancier grow light set ups have instructions for the distance they need to be from anything growing due to how powerful they are.
I put two shop lights on each shelf. If I were to have all the shelves have lights that would mean 8 lights total. The lights have gone up in price since I purchased them and are around $29 each. To outfit my entire station that is a cost of $240, but maybe you don't need 4 shelves of lights and you can get by with fewer.
I use pulleys to attach the lights to the wire shelves.The pulleys make raising and lowering the lights as the seedlings grow exponentially easier than the chains that come with the lights. I typically attach the tops of the pulleys to the shelf with zip ties and the pulley to the light with a zip tie also instead of the metal clips that come with the pulleys. This gives me additional space on the shelf. Before I purchased the pulleys, I have accidentally dropped an entire light on top of a tray of seedlings while trying to adjust the lights with their chains.
Some seeds require more warmth than others and a heat mat can aid in germination rates and speed. I have three heat mats to use when needed especially on peppers and tomatoes, or in general if my seed starting station is in a cold location like a garage or basement. I have not seen the need for paying more for a heat mat with temperature control, but if you like being super precise, those exist for a bit more money. These heat mats are $16 and I get the 10"x20" which fits a 1020 tray perfectly.
Not necessary depending on your electrical set up, but an outlet strip can come in handy. If you don't have linkable lights it might even be necessary.
I am able to plug the entire outlet strip into an indoor outlet timer and all my lights and heat mats will be on the timer. Lights are usually on for 12-16 hours per day.
A thermometer to keep track of temperature fluctuations and humidity can be extremely helpful in monitoring conditions of your grow space. This is a bluetooth thermometer and allows me to see the temperature and humidity in my grow space, but it is not wireless and does not allow you to check while out of town. It is nice to check the high and low over the last 24 hours because it will let you see how cold your space got overnight while the lights were off. Typically you will not need one if your grow station is inside your house, but knowing how warm it is under the lights might be nice. If your grow space is in a cold basement or garage, the thermometer will let you know if your conditions are right for starting seeds. If it's too cold, many seeds will not germinate.
There are a lot of choices when it comes to seed starting cells/trays/humidity domes. I have been using Bootstrap Farmer brand equipment and love how durable it is.(These 1020 trays are nothing like what you get from the nursery. They are strong enough to let you carry an entire full tray with one hand and it will not bend) I put two 1020 trays (that just describes the size of the tray, 10 inches wide by 20 inches long) on each shelf. I can then use various pots/seed cells in them. I like the 6 cell air pruners for starting seeds. This allows me to move the cells out from under humidity domes as the seeds sprout.
I like the 2.5 inch humidity domes, but they also come in 6 inches tall which can be good for propagating cuttings.
I like the 6 cell air pruners for starting seeds. This allows me to move the cells out from under humidity domes as the seeds sprout.
When I pot up the seedlings out of the 6 cell trays, I pot them up into 2.5 inch extra strength pots. They come in colors and black and I like to purchase them with the 32 cell reusable trays to keep the pots from tipping over in the trays. (The black pots have a purchase option for the 32 cell tray to come with it, but the color pots have to have it purchased separately.
If I get to the point of needing to pot up one more time before planting out, I use the 5 inch pots with insert.
If you are going to be soil blocking I use a Ladbrooke 2 inch soil blocker. Many gardeners use the mini soil blocker, but I have not wanted to mess with having to move them up into larger soil blocks. I like using a deep mesh 1020 tray for soil blocks as it allows me to water them, and then lift them out of the 1020 to drain the excess water.
A few final thoughts: it can be hard to find space indoors for a seed station of this size, if you go the basement or garage route, in addition to the cold temperatures you may find that something is eating your seedlings. I found a mouse eating my seedlings when I had them in the garage one year. The most important thing is lighting, but again, a desk lamp positioned over a repurposed food container with a clear lid (lid acts as humidity dome) can work just fine. If you are new to seed starting, maybe try something on a smaller scale until you get a feel for things and if you even like starting plants from seed. It can be less expensive, but not in the short run if you have to buy all the equipment. I have never had to replace a shop light in my set up, and the metal rack does double duty as storage in our garage when I'm not using it for seeds. After several years, the set up does pay for itself in terms of not having to buy plant starts as seeds are so much less expensive.
I do think having the station indoors where I can sit next to it and enjoy the boost of light from the shop lights and smell, touch and look at something green growing in the dregs of winter is good for my mental health. As gardeners, many of us need a dose of green in the winter. Please reach out if you have any questions.
**The links provided in this post contain affiliate links and I receive a small percentage from the brand company. This does not raise the cost for you, it is paid fully by the brand. These small earnings help fund my garden endeavors and make it worth spending the time to put together posts like these.