Monday, February 15, 2016

Grow Seedlings or Microgreens Under Lights in Northern Alberta

Mountain Magic cherry tomato grown under lights
In winter, my seedlings and microgreens need more light. They sit in a south window, but in February in a northern city like Edmonton, Alberta, they grow spindly. I run a soft fan across the seedlings for ten minutes a day to keep them strong, but still they are 'leggy' and pale. 

Google search. 'Weed' sites have taken up the 'grow box' problem with vigor. Pot head solutions seem a bit complicated and expensive. I need a simple, cheap and energy efficient solution. 

My seedlings sit on a 4 tier metal wire shelf positioned up against a south window. These shelving units are inexpensive and easy to put together. Big box stores sell them. 

An industrial clamp light
Light source? 

Clamp on to the shelf, over the plants, an industrial clamp light with a 100 watt (aka 23 watt) compact fluorescent bulb (CFL). According to the package, this bulb lasts 9 years - so shine away! 

At first, I had a reflective space blanket around the shelf, but the lights give off some heat and the blanket keeps heat in.  I removed the blanket. 


After viewing the excellent videos about growing with lights by Alberta Urban Garden, I altered my system by adding another lamp next to the first light. One light is a 6500K CFL bulb and the other is 2700K CFL light.  Microgreens will grow well under just the 6500K, but in order to flower, plants need the lower 2700K as well.

Broccoli microgreens

Update: January 2017. I could not resist planting a cherry tomato seed (Mountain Magic) much too early. Below is a picture of the plant at about 4 weeks. At the first site of the stem, before it even fully emerged from the ground, the lights were on. They shine for about 16 hours a day. If the leaves are too close to the lights they dry and crisp, so I keep the bulbs at least 4 inches away. The extra heat is a plus near the cold windows, but if too close the leaves will be damaged. As the daylight hours lengthen, the sunlight from the window compliments the artificial light. 


Tomato plant - 4 weeks- under lights- next to window in mid January.


Update: February 16, 2017

Same plant - cherry tomato Mountain Magic 8 weeks from seeding.
Tomato plant growing in southern window with lights. Lights on 12 hours/day.


Box fan on low speed, circulates air and strengthens leaves and stems. 
The box fan has a furnace filter on it (20 X 20 Filtrete). The filter is not necessary for the plants, but it reduces winter dust and cat dander allergens. This is an easy set up.  When the fan is on, the filter is sucked up against the fan. This homemade DIY air purifier works well.

In the basement, I set up the same wire shelving system with tube fluorescent lights that hang 2-4 inches above the plants. The lights are on a timer - and they shine for about 16 hours/day. The baby arugula is ready to harvest.
Arugula growing under fluorescent lights 6500K. 
Baby arugula, ready to harvest, grown under fluorescent lights in the basement.

Update: The fluorescent tube lights in the basement have worked out really well. I started peppers, impatients, rosemary, sage, and parsley in early February and tomatoes, kale, butter lettuce a few weeks later. I replaced one of the four 6500K bulbs with a 2700K bulb. Lesson learned - keep the plants a good 4 inches from the bulbs, as the leaves will fry easily.
Microgreens sunning outdoors in a mild February in Edmonton.
Check out my short but informative video on how to grow great garlic in a cold climate.