DIY Indoor Seed Starting System




Introduction: DIY Indoor Seed Starting System

About: I'm a Mechanical Engineer who has been a part of this community for over 10 years! My interests have evolved over time, and now center around 3D printing.
I have for a long time wanted to try my hand at growing something.  I think it's awesome to be able to grow food oneself, instead of buying it from large-scale farms, after it's been processed and shipped thousands of miles.  For this reason, I decided this spring to attempt to grow some crops of my own.  However, in Northeast Ohio, winter lasts too long, and spring comes around too late to plant seeds outside initially.  This system allowed me to start my seeds about mid-February, and keep them inside until the weather wouldn't destroy them.

This Instructable will focus on what I used and built to start my seeds rather than in-depth gardening theory.  This is because this project was my first attempt at growing plants, and I am far from an expert gardener.  This project was done for fun and learning about gardening, while still trying to be able to harvest some produce, in a cost-effective manner.
  1. Choosing What to Grow
  2. Pots and Planting
  3. The Frame
  4. Lighting
  5. Conclusion
5/21/2012: Thanks for the feature!!
6/7/2012:  A sincerest thank you to all who read and voted for this Instructable in the Gardening Challenge!  Second Prize!

Step 1: Choosing What to Grow

Since this is my first attempt to grow any plants, I wanted to start simple.  Therefore, I chose to try to grow sunflowers and tomatoes. 

I assumed that sunflowers would be less maintenance than other vegetable plants because they're flowers.  I'm not sure what my logic here was, but that's how I saw it : ).  Also, sunflowers can have their seeds harvested and eaten, so not only do they look nice, but produce food.  The seeds that are harvested can also be used to plant more sunflowers next year.  As for tomatoes, I made another assumption that tomatoes seem to be a popular starting point for gardeners.

I went down to Home Depot and grabbed some seeds.  I got four breeds of sunflowers, and one of tomatoes.  If I could do this project over again, I would have gotten less variety, in an effort to keep things relatively small and simple for my first gardening experience.  The sunflower breeds I bought were: American Giant, Mammoth, Autumn Beauty, and Teddy Bear.  The tomato seeds I bought were Beefsteak Tomatoes.

Step 2: Pots and Planting

The first thing I did was decide what containers I wanted to start my seeds in.  On Instructables you'll see everything, from pop bottles to egg cartons, to bio-degradable options.  I did not have egg cartons or a sufficient amount of pop bottles, so I took a trip to the dollar store, and found small, thin, plastic pots.  I got twelve in a pack for a dollar, and bought six packs. 

I took a trip to the garden store after that, and told the employee there that I needed a bag of dirt.  I bought the MiracleGrow stuff in the picture below.  It occurred to me later that actual seed-starting soil/pellets are sold, and could have been better for this step.  However, the soil I bought worked fine as well.

I then set up in my garage, planting seeds of each variety, making sure to keep everything organized by species.  I ended up with 70 plants, and used that number to help decide how large of a frame to build to hold all of the small pots.  I wanted to have a fairly high number of plants to account for seeds that may not work, and plants that die early.

Step 3: The Frame

Now that I had 70 little pots sitting on the floor of my garage, I needed a place to move them so that they would be able to receive sunlight and grow.  Living in suburban America, this can be a challenge, so I built a frame to hold all of the plants to help keep them organized.

The frame was built using 1/8" thick plywood, salvaged from a wooden pallet I found a long time ago.  It is held together using hot glue.  I wasn't particularly worried about the strength of the frame, since it would only be sitting inside.  The pieces were cut using a jig saw, using measurements from the small pots as a guide, to allow for ten columns of seven plants each.  Two columns would be used for each species.  The pots hang slightly about the floor, balanced between the two pieces of wood on each side.  Newspaper is placed underneath the frame to catch and absorb any excess water.

Step 4: Lighting

Based on countless random sources online, I knew that the light from the largest windows in my house probably wouldn't be sufficient for my seedlings.  Also, on cloudy days, I couldn't have the young plants receive no light all day.  Grow lights are the solution to this problem.

The stand is made up of two-by-fours that I had left over from another project.  They are cut and nailed together into a T-shape, and a notch was cut into the top using a jig saw and oscillating cutting tool.  A large aluminum pipe that I've had laying around for a long time was cut to fit between the two T-shapes.  I bought two light bulb sockets used for lamps and compact-fluorescent flood lights from Home Depot.  The flood lights I chose seemed to have the best lumen-per-dollar ratio of the compact florescents that I looked at.  The sockets I chose to have a twisting switch built in, so that the lights could be easily turned off.   The sockets were attached to the aluminum pipe using small pieces on bendable steel and screws to create a sort of bracket.  Both the steel and screws were taken from some sort of appliance a long time ago.  The bulbs were wired in parallel, using a long wire salvaged from a vacuum cleaner.

My only costs here were the light bulb sockets and the bulbs, which came to less than $15 USD.

Step 5: Conclusion

After the set-up is complete, the only thing left to do is water the plants regularly, and wait for them to grow!

Thanks for reading!  I like comments, so if you would like to leave one, don't be shy!  They help keep me motivated to keep posting Instructables.  Also if you wanted to rate this Instructable and follow me, that would be awesome too. : )

If you really like this Instructable, it is entered into the Gardening Challenge contest, and I would really appreciate a vote.

Thanks again, and good luck gardening!

Gardening Challenge

Runner Up in the
Gardening Challenge



    • Metalworking Contest

      Metalworking Contest
    • Creative Misuse Contest

      Creative Misuse Contest
    • Fix It! Contest

      Fix It! Contest

    48 Discussions

    I hope so, I can't imagine those seeds are any different from a tomato seed, except the fruit is sweeter

    a grate gide for growing sunflowers ^

    Be creative in looking at everyday objects. I try to re-use whenever possible. Some of my favorite pots for my seedlings are Venti cups from Starb..., 1/2 gallon ice cream cartons, and extra large soda cups. I have 18" x 4' x 4' raised beds, all built with donated scrap lumber. With a keen eye and a little luck, the possibilities are endless. I hope you are still gardening...

    1 reply

    Unfortunately the gardening didn't happen this year, even though I managed to harvest seeds from all of my sunflowers last year with the intent to plant them this year.. Being away at college interfered, as I wasn't able to start my seeds early like last year..

    Thank you!! It's my first project of the day. I'm so happy : )

    I don't really care for the seed starter pellet thingies.
    the seed starter soil to a certain degree, but, Best results Ive ever had starting seeds is using a 5-5-0 manure.compost blend.
    I good commercial brand is called "Black Cow" composted cow poop with other organic compost mixed in.. no, it's past the point of stinking so don't worry about that. lots of nutrients.

    the miracle grow dirt you got there is potting soil and its best used for already established house plants. overall, it has a lot of nitrogen in it. and not much of anything else.

    the lights, just because they are bright, dont mean they are right, as said earlier, a full spectrum bulb, just get a "grow light" type of bulb and the plants will be much happier. general purpose CFL's just don't cut it.

    where will the seedlings be going once planted?

    sunflowers and tomatoes both demand full sun, Tomatoes really really want a good composted soil to grow in. An old country trick is for when you are digging your planting hole is to drop a chunck of cow patty in the hole before planting.. I can attest that this works VERY well, but admidt that in our modern times, cow patty is hard to come by. once again, back to the Black cow gardening dirt.

    4 replies

    Hi there!
    Next year around I'll definitely have to look some better soils to plant in then.
    Most of the sources I looked at suggested CFL's as an alternative to expensive High-Pressure Sodium bulbs, and that the CFL's would suffice, but there's undoubtedly better out there.
    The tomatoes have been going into hanging pop bottle planters, and the sunflowers into bigger pots.
    Haha.. No cow patty in Suburbia : )

    Thanks for the comment!! : )

    CFL bulbs would be a big improvement since seedlings are so sensitive to high temperatures. Also don't put any sort of manure near seedlings the salts, heavy metals and ammonia are very detrimental to germination rate and root development.

    to a point I guess, depends on the type of poop you are using I would reckon. compost made from deep bedded straw from a chicken coop would be fine, composted cow manure like I recommended up there would be fine as well.. I certainly wouldn't start a seed in the middle of a straight up cow patty. though I have composted my beds using Elephant poo from the Circus.

    High pressure sodium bulbs are good if you have an extensive indoor hydroponic grow operation dealing with mature plants. live in California, and have a doctors prescription. otherwise CFL GROW lamps or regular incandescent grow lamps are just fine.. in fact, I would dare say the incandescent are a better choice BECAUSE of the heat the produce.

    if you are doing the mini green house thing, the light bulb's heat is going ramp up the humidity in the enclosure and spur germination, I wouldn't move to a CFL until you are trying to harden the seedlings for transplant.

    Now wouldn't an online Cow Patty store be a great idea for people that don't normally have access to such items?
    A good side business. What's the overhead? Nothing! Lots of heavy plastic bags.

    The biggest issue I have found with transplanting anything is if the pots they are growing in do not release the soil easily, so it takes a lot of pulling, stress on the stem and ripping of the roots to get the plant out.

    Otherwise, try not to do it in the heat of the day, a cool evening when the temperature will be only moderate not hot for the next few days (and no strong wind or rain forecasted) would be best.

    Here's a couple of tricks I use.
    1. Line the inside of the pot with aluminum foil (with drain holes of course).
    It comes out cleanly and easily. All you have to do is pull the foil away from the soil and its ready to go.
    2. Cut a circle of plastic screening to fit the bottom the pot. Using a washer and small screw, attach it to a wooden dowel a couple of inches higher than the pot. Then, just lift the whole thing out by the dowel.
    Both are very inexpensive.
    What do you think?

    A member of our church congregation gave away extra plants from his greenhouse this year by leaving boxes of them by the entry. The plants were started from seed in ziplock sandwich size bags. The bags were filled with miracle grow and the seeds took off like magic. The bags allowed enough air in the sides so no drainage holes were needed. At transplant, I just tore the bag down the side and put the contents into a small hole in the garden. Gonna do that next year rather than the peat pellets I use.

    Thankfully, I haven't had too many issues with the soil not releasing so far, but I will be trying to transplant some later today.

    Thanks for the comment! : )

    The biggest issue I have found with transplanting anything is if the pots they are growing in do not release the soil easily, so it takes a lot of pulling, stress on the stem and ripping of the roots to get the plant out.

    Otherwise, try not to do it in the heat of the day, a cool evening when the temperature will be only moderate not hot for the next few days (and no strong wind or rain forecasted) would be best.

    That's entirely possible! I'm not a pro gardener, but so far I haven't had any problems moving my sunflowers to different pots. I've had way more problems dealing with weather and such, but not transplanting.

    Thanks for commenting! : )

    HI been doing this for a couple seasons , still learning.
    I had room for a 4x8 piece of plywood, put some 2x4s on it and put plastic in to keep it water tight, i use Metal Halide Light to start, when plants have 2 or 3 sets of leaves showing then switch to high pressure sodium light, and have a oscillating fan going, it really helps, all on a timer !
    when they get 4 or 5 inches tall i put them in plastic cups with several holes in the sides for water, once a week i add 10 gallons of water, which i have in buckets at least for a day to vent the chlorine out , the fan keeps the mold issues at bay and strengthens the plant to and i add a organic fertilizer once a month or so !
    This is a good starting point and when then get 6" or so i move them out to my front porch enclosed to adjust !
    This works well so far for me, am in syracuse ny so weather is a issue here to !
    This is a basic starting point for me have had good results so far !
    I would like to start the hydroponic thing with this to a small pump to keep the water moving, but have some concerns about fertilizer/food and putting them out side in soil, can they convert to soil will find out on that !
    Thank u for doing this it helps us all, we all need to update r skill level especially in these times, seems to be a lost art growing ur own food !!
    Good luck in ur planting and please pass along ur results and everyone else please its all good for us !!!

    Thank You !!