Starting Plants from Seeds Indoors (Part 1 – DIY Lighting Set-Ups)

David Marshall, Halton Master Gardener

Editor’s note: I’m delighted to feature our 5-part series that step us through the entire process from building your own seed-starting set-up through to planting your hardy transplants outdoors. In the final month, David will tell us about taking cuttings from flowers and shrubs. I’ll personally be following David’s advice in these articles – it’s my first attempt at growing plants from seeds. I’ll keep you updated on my experience on our Halton Master Gardener’s website. Just today, I ordered my seed catalogs as per David’s suggestions. Join me in starting your own seeds indoors. Jo-Anne

It’s only February, but it is already time to think about your summer garden. Whether you grow flowers or vegetables, it’s fun to start your own seedlings. You can grow varieties which you will not find in stores, and you can save a lot of money.

Window sill growing is not really satisfactory because in March, day length is not adequate so your plants will be thin and spindly. Grow lights are the answer but a commercially available set-up can easily cost as much as $900 or more – that’s a bit daunting. It is, however, easy to make your own grow light set-up at a fraction of the cost.

Lighting: Traditionally 24 or 48 inch fluorescent tubes were used, but the advent of compact fluorescent bulbs (CFLs) and more recently light emitting diode bulbs (LEDs) have made the job easier. I mostly use LEDs now because they are more efficient, give off less heat, and last longer.

The quality of the light is important for good growth. The visible spectrum runs from violet through blue, green, yellow, and orange to red, but plants use mostly the blue end of the spectrum for germination and growth, and the red end for bud formation and flowering. Each of these colours is associated with a K value (Degrees Kelvin) ranging from around 3000K for warm white, 3500 – 4500K for cool white, and 4500K – 6500K for daylight. The ‘K’ number or sometimes just the name such as warm white, cool white or daytime is printed on the bulb and the box.

Because we are concerned with germination, we need the higher numbers, so I use a mix of daylight and cool white which gives mostly blue with a bit of red to help bud formation.

3 DIY Cost Effective Set-ups

These three grow light fixtures are easy to make yourself. Once the fixture is made, you just need to plug it into a timer set to 16 hours of light.

DIY Set-up 1

The first setup is the most economical and made almost entirely from Styrofoam.

Materials

– 1 Styrofoam handipack (About $14 from Home Depot) which consists of 8 sheets of 48” x 14” ¾ inch thick Styrofoam; enough for two units. (You can, of course, use any size Styrofoam sheet and cut to the required dimensions)

– 4 plastic lamp holders

– 4 light bulbs, (LED, CFL or a mix) 13 watt for CFLs or 9 watt for LEDs

– 1 piece of 24 inch by 12 inch plywood

– 2-strand electric wire and a plug

– 12 three inch nails and some white glue

Make the Styrofoam box

Cut 3 of the Styrofoam sheets in half such that you have 6 24”x 14” pieces.

To make the base, glue two pieces together along the 24” sides for the base such that you have a 24 x 28” rectangle.

To make the 3-sided box, set up three pieces so that the box is 14” high, with 24” sides. Pin the sides together with nails and a dab of glue. Tip: Not too much if you want to disassemble it later.

Cut a 4 inch strip (4” x 24”) from the remaining piece and use it to close the top part of the fourth side. This leaves a gap so that you can slide the seed flats out for watering. (not pictured)

Make the Light Source

To make the light source, wire the four lamp holders together, attach the plug, and screw them near the corners of a 24 inch by 12 inch piece of plywood which will rest on the top of your box.

DIY Set-up 2

Use the same box as in Set-up 1, but for the light source, screw a lamp holder onto plywood as before and join together three twin lamp holders (also called double socket adapters) as shown in the photograph to a give a four bulb ‘fixture.’ In this case, screw the light fixture into the middle of the piece of plywood rather than in the corners.

Both Set-ups 1 and 2 hold two flats. If you prefer, you can make them 36” wide to hold three flats. Remember to adjust the lighting source by using 6 bulb instead of 4 bulbs.

DIY Set-up 3

Setup 3 is even easier. Instead of building the box from scratch, use a 24” wide three or four shelf resin shelving unit made from a kit sold by most big box stores. (this is HDX brand). It uses 1 ¼ inch plastic tubes easily assembled without tools to hold six or eight flats and costs about $40.

Make a bulb holder as above and support it over the shelves by 14” high Styrofoam or plywood pieces at each end of the shelves.

In any of the 3 Setups, you can of course use 24” fluorescent tubes as before, but it will be more expensive.

Even if you are not planting seeds, the seed catalogues make interesting reading. I mainly use four suppliers and they will be happy to send you their catalogues, or you can browse and order on line.