Best Low-Cost Indoor Seed Starting Supplies

This is my low-cost setup for indoor seed starting. I use items found in any department store, some of which you may already own. There is no need for expensive equipment to grow healthy starter plants for your garden.

This is part of a series, Indoor Seed Starting for Beginners | Sow Indoors Grow Outdoors, where I walk you through the indoor sowing process from seed to garden. It’s all the information I wish I had when I was getting started.

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Best Low-Cost Indoor Seed Starting Supplies

This is an excerpt from the ebook, Seed Starting for Beginners: Sow Inside Grow Outside, sharing everything you need to know to start your own garden plants from seeds indoors.

If you would like the entire ebook with all the printable lists in one handy file, you can save it instantly here.

Here I’m showing my favorite cheap (low-cost) and effective seed starting supplies for growing seeds and young plants indoors.

If you need ideas for finding used items, also see these thrifty shopping tips.

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Contents

1. Indoor Seed Starting Supplies
   1. Lights
   2. Shelves
   3. Hanging Hardware
   4. Trays & Accessories
   5. Seeds
   6. Seed Starting Mix
      1. Homemade Seed Sowing Mix
   7. Soil Blocking Tool
   8. Seed Trays & Containers
   9. Plant Tags & Labels
   10. Digital Timer
   11. Watering Can
   12. Seedling Heating Mat
   13. Fertilizers
   14. Cleaning Supplies
   15. Electric Fan
   16. Blocks of Wood
2. Recommended Books

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Indoor Seed Starting Supplies

1Lights

There are lots of fancy grow light systems on the market, but there really is no need to spend that kind of money.

I started out using standard fluorescent light units commonly used in basements and workshops, and I’ve stuck with them ever since because they work.

My seedlings grow beautifully indoors, and become strong, happy plants outdoors.

• Fluorescent light fixture | I use light fixtures that use T8 and T5 fluorescent bulbs. Find some ‘warm’ and ‘cold’ bulbs if you can. Also, be sure to get the units that hang from the ceiling, not the type that are hardwired into the ceiling.

Fluorescent light units come in 24-inch, 36-inch, and 48-inch lengths. If you are going to suspend the lights from shelves (see below), choose units that match the length of your shelves, and get two units per shelf.

2Shelves

My ideal setup is a shelving unit on wheels with two fluorescent light units suspended on the underside of each shelf.

You could also use wall-mounted shelves if they are strong enough to hold the weight of the lights.

A distance of at least 14-inches between shelves is desirable—adjustable shelves with a wide range of options is even better. You need room for the lights and for the plants to grow.

The longer you intend to keep them under the lights, the more room you’ll need. Plus, some species grow much taller than others, of course.

I mention wheels, because it’s super handy to be able to move the entire unit around to access the seedlings for watering.

• Wire shelving unit | Be sure to check yard sales and thrift shops or place a wanted ad for stuff like this.

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3Hanging Hardware

The design of fluorescent light casings can vary quite a bit between manufacturers.

I find that the tube bulbs are prone to coming loose, so I add cable ties around the entire light unit to ensure the bulbs cannot fall from the fixture.

The next task is hanging the unit.

As your seedlings grow, you are going to either adjust the seeding trays or lights, so they stay the desired distance apart.

The lights should be 2 to 3-inches above the tops of the seedlings.

• Pulley hangers like these ones are one option, making it pretty easy to adjust the lights.

• Metal S hooks are also helpful. Some light units have metal suspension chains and require S-hooks for hanging, others come with them.

Another trick is to raise your plant trays rather than lowering the lights. I collect drink cup holders from fast food restaurants: you can stack them up to the exact height needed and place the seedling trays on top.

4Trays & Accessories

Here are some things to consider.

• Waterproof tarp | I don’t find seed starting particularly messy (once the seeds are sown), but, it’s good to have your floors protected in case some water or soil spills. Choose a tarp larger than the base of your shelves. I double mine over for extra peace of mind.

• Plastic boot trays | I use boot trays on each of my shelves to hold the seed trays and catch water spills. If you can find the style with raised edges, that help hold water, even better! These can be hard to find though. I like them because they catch drips and you can water your seedlings from below by aiming the watering can right into the tray.

Alternate options:

• Seedling trays from a garden nursery: choose the type that are watertight, not the ones with drainage holes.
• Lids from large plastic storage tubs can also work.
• Old baking sheets with deep sides are good drip catchers too.

5Organic Seeds | Local if Possible

Why organic? 

If you are an organic gardener, your seeds should be too! I want to grow plants from seeds that come from parent plants that experienced the same growing conditions that I provide in my garden.

I try and keep my soil as rich and healthy as possible, but, beyond that, I mostly leave my plants to fend for themselves.

I do not coddle or treat them with any sprays.

If a plant is weak and struggling and the cause seems to be systemic (not a factor within my control), I get rid of it.

I want my plants to be strong and fend for themselves (happily).

Why local? 

By choosing a local, organic seed grower, they’ve done half my work for me.

I know the plant is suitable for my growing zone and (perhaps) conditions because they’ve grown it already, numerous times over.

This said, there are plenty of plants that are suitable for vast growing areas, so there are plenty of options for seed sources. 

Local could mean your region or country or other defined area that shares the same climate and growing conditions.

• Canadian Seed Company Directory
• United States Seed Company Directory
• How to Choose the Best Seeds for Your Garden

If you want to check if seeds are viable prior to sowing in soil, use this seed viability test.

6Seed Starting Mix

We say seed sowing ‘mix’ or ‘medium’ because the right stuff to use indoors does not contain soil. Indoor seed sowing is a different beast.

Away from the natural checks and balances of the outdoors, we have to create a clean sowing environment, free of pathogens.

• Seed Starting Mix (Soil-less) works very nicely for seed sowing. Read the ingredients and be sure it’s free of additives such as synthetic water pellets or synthetic fertilizers, which are not beneficial or desired. The stuff I buy is organic. You can also make your own seed sowing mix (more on this below). I do this if the ready-made stuff is more expensive than the cost of the individual ingredients for the same total volume.
• Homemade Seed Starting Mix has a recipe for mixing your own.

When your seedlings are a couple of inches tall, if there’s a few weeks before last frost, you should move them to 3-inch pots with organic potting soil for containers.

Have you heard it recommended to sprinkle cinnamon on your seed starting mix to prevent fungal diseases? This looks at the research on cinnamon as a fungicide and whether it’s worth trying.

7Soil Blocking Tool (Optional)

This is my favorite seed starting tool although you can start seeds just fine without one. It is used to form solid little block of seed starting mix.

Seeds are sown in the blocks.

Once seeds have sprouted, these soil blocks are super simple to move around and/or transplant. 

There is a demonstration video here that I recorded several years ago.

• Soil blocking tool | I use the size that makes four 2-inch blocks.

Another good feature is, you can prepare trays of soil blocks ahead of time and simply re-dampen them at seed sowing time.

You will not need this tool if you want to use open trays or small, plastic pots instead.

8Seed Trays & Containers

What you need will depend on how you want to do this. There’s no right or wrong way. Often it comes down to what supplies you have or can easily obtain.

I start my seeds in seedling trays (obtained free from garden nurseries when buying plants) and use soil blocks, as mentioned above. Sowing directly into trays or pots is fine too. Whichever way you go, ensure there is drainage.

• Seed starting trays | Get tray sizes that works with the size of your pots or soil blocks, and the size of your shelves.
  
  You want to fit as many plants as you can under the lights without wasted space.
  
  New seedlings are tiny, of course, but as your plants mature, they will grow taller and wider, and take up more root space.
  
  These trays are very handy for holding a group of pots and protecting your shelves and floors from drips.
  
  You can sometimes get them free when purchasing nursery plants.

• Plastic garden pots | I save plastic pots from garden nursery purchases and our local garden recycling depot.
  
  With the soil blocking method, I first start the seedlings in soil blocks without pots.
  
  Once they are a few inches tall, I plant the soil blocks with the seedlings into small pots (2.75 to 4-inches wide, depending on how big the seedling is and what I have on hand).
  
  It is ideal if the pots are square and fit nicely in the seedling trays, to make maximum use of the available light.
  
  As the plants grow, I use more lights.As mentioned, you could sow directly into pots.
  
  In this case, figure out how many pots (of what size) fit nicely with your trays/shelf and light size.
  
  In some cases, you won’t need to transplant to bigger pots before planting outdoors, in other cases, you will.
  
  It all depends on the plants, how big they get, and when your last frost date is.

9Plant Tags or Labels

It’s really important to keep track of your seedlings so you know what’s what. There are a few options.

Easy Homemade Tags

If you want to make plant tags or labels for your seedlings, this lists all the best (cheap and easy) options for making tags.

The most popular options are HB 2 pencil, pen, or a water-proof fine-tip pen on plastic or vinyl tags. You can buy tags or make them from cut-up (lead-free) window blinds.

Label Your Seedling Tray

With my tray method, I actually mark the tray instead of using tags for the seeds and seedlings. You can see my grid labeling method here.

Basically, I mark the tray like the cells in a spreadsheet (rows and columns) and track everything that way.

One other advantage to this is, tags are hard to fit under the grow lights when the seedlings are still small, so better to mark the trays instead.

Once seedlings are in pots, I use plastic plant tags and a paint pen.

For reusing tags, to save money and avoid creating plastic waste, use these instructions for removing marking pen from surfaces like plastic.

10Digital or Mechanical Timer

It’s important to have your grow lights (fluorescent lights) on for a set amount of time every day.

Because mine are in our living area, I like them to do double-duty, so I put them on in the evenings when we can also make use of the light.

I use a basic 24-hour mechanical timer to turn them on and off. I run them for approximately 12 hours at a time. I’ve tried numerous digital timers and none of them kept good time! But the mechanical ones are inexpensive and work fine.

You will notice that others advise running grow lights for 14 to 16 hours a day. I found this to be too much, probably because my plants are also getting some sunlight during the day.

If your home is dark, give them 14 hours a day and see how it goes.

11Watering Can

It is best to water the soil / growing medium, not the actual plants. The soil blocks make it easy to water ‘from below’, letting the medium and plant roots soak up the water.

• Watering can | Look for a watering can with a long, skinny neck. You need to be able to get to your plant roots without a bulky watering can knocking into the grow lights.

12Seedling Heat Mat (Optional)

Every plant species has a temperature sweet spot for germination. We’ve been told all seeds like plenty of heat but it’s just not true. But, realistically, we’re not going to provide an individual temperature for each seed we’re starting so instead it’s good to work with a basic range that suits many types of seeds.

For most seeds, a soil temperature in the range of 65-75° F (18-23° C) will allow germination.

This has a list of best soil temperatures for vegetables seeds and flower & herb seeds here.

This guide explains how and when to use heat mats for indoor seed starting. Contrary to popular advice, they are not always helpful or the small benefits do not justify the time and cost.

Also, I came up with this list of suggestions for other ways to warm your seedlings, making use of existing heat in your house, which may also help.

13Fertilizers

Seeds contain all the nutrition and energy needed to support germination. Then, as a seedling grows, it relies on its environment for sustenance.

Needs vary by plant type, but, you may want to add a liquid organic fertilizer (in low doses) to your plant water as your seedlings grow.

Check the instructions on the label and reduce the dose by half (or more) since your seedlings will be little guys and too much is not beneficial and can be harmful.

I have not tested these specific products, but they will give you an idea of what’s available.

• Organic Liquid Fish Fertilizer
• Fish and Seaweed Blend Fertilizer
• Tomato, Vegetable, and Herb Liquid Fertilizer

14Cleaning Supplies

Before using any new or repurposed garden pots, trays, tags, or containers, you need to wash and sanitize them.

I wash mine in a tub of mild dish soap, rinse thoroughly, and then soak in a bleach solution (4 teaspoons bleach per quart of water for at least one minute) to disinfect.

Rinse thoroughly and allow to dry before use.

• Dish soap
• Household bleach

15Electric Fan

Once your seedlings have sprouted, an oscillating electric fan can help prevent insects and other problems from occurring.

You can include it with the light timer settings, or run it for shorter times. Choose longer times if you have houseplants prone to things like whiteflies.

If you’re growing on tall shelves, you might want a standing fan or one that clips on the shelf posts.

16Blocks of Wood or Something Similar

Height Alert

If you grow a variety of seeds, you may find that your seedlings are growing at different rates and reach very different heights.

This will require some adjustments as you need to keep the grow lights just 2 to 3-inches above their heads.

To accommodate different heights, as things grow, I group same-height seedlings together in smaller trays.

Where needed, I add stacks of fast food drink trays and scrap pieces of 2x4s under the trays to bring the shorter plants closer to the lights.

This will all depend on what you grow, so keep this in mind and have some supplies ready in case you need to do some height-shifting.

And that’s it!

Now it’s time to sow some seeds.

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~Melissa the Empress of Dirt ♛