Square Foot Gardening in South Africa

Having a seedling rack with heated pads and special grow lights to be able to sprout and grow your seedlings indoors is, while not a requirement of Square Foot Gardening, most definately a bonus. In this way, you can grow your seedlings throughout the year.

What you do with those seedlings during winter is then up to you. We will be growing as many of them as we can in a variety of pots, barrels and even in an old metal bathtub. Those seedlings that we do not have enough containers for, we’ll put out into the SFG boxes, test various methods of keeping them warm and protecting them from frost and just generally see what happens to them.

Building the seedling rack in itself was pretty easy but trying to find suitable heating pads and grow lights was a little more difficult. I found a picture and basic plan online, popped in to my local builders warehouse for some wood and screws and put it all together in a couple of hours one night.

I did a fair bit of research to find out about special growing lights for seedlings and came away even more confused than before. There is a lot of conflicting information out there on this topic. I eventually went with the information provided by the guy who designed the growing rack and decided to go with two 2ft (double) fluorescent light fittings (for two of the shelves) with a ‘Cool White’ and a ‘Wide Spectrum’ tube in each fitting.

Only after I had purchased the fittings did I find out how difficult it was to find the ‘Wide Spectrum’ tubes. Most people didn’t have a clue about what I was talking about until I specifically mentioned that they were used for growing plants… “Oh, Grow Lights” they said, “well why didn’t you say so? Yes we do sell them but they are out of stock“. Everywhere I tried was “Sorry, out of stock“. I have a few 2ft ‘Grow Light’ tubes on order now but who knows when they will come through. And, I still don’t know if these ‘Grow Lights’ are the same things as a ‘Wide Spectrum’ tube

So for the moment I am just using plain ‘Cool White’ tubes and I must admit that the seedlings are still doing very well under these globes. It will be interesting to see the difference that a ‘Grow Light’ tube would make, if any at all.

The heating pads were another story altogether. Most of South Africa does not have the same harsh winters as found in the USA, Canada and across Europe so we therefore also do not have the same range (and cheap pricing) of heating products in our country that is commonly available overseas. I came across one or two small, really expensive heating pads specifically designed for seedlings but, due to the prices, I decided to expand my search into various other markets too.

I thought of underfloor heating and spoke to a few people in the industry but it gets rather complicated when you start working with thermostats (they get pretty hot), waterproofing and coverings, sizing etc. I did however, find a 60cmx40cm heated ‘Foot Mat’ at builders Warehouse for R350 – no thermostat, just a low and high setting. I bought it to test.

Then I looked at the pet industry (fishtanks and reptiles) and found a few Reptile Mats in various sizes that could possibly work. Again no temperature settings but a little more waterproof than the Foot Mat so I bought a 35cmx35cm one for R90.

To make the Foot Mat waterproof I simply covered the top with a black plastic dustbin bag – overlapping it a bit on the bottom edges but leaving most of the bottom open so as not to ‘overheat’ the mat and burn it out. The Reptile Mat has a thin ‘foil’ covering so I am using it ‘as is’ (just being very careful not to tear the foil).

The ideal soil temperature for growing seedlings is between 24 and 28 degrees Celsius (depending on the plant) and I was a bit concerned that these heating pads would either be too hot or too cold. I needn’t have worried, at the pet store I also bought a ‘floating’ thermometer and have used it, pushed into the soil of a ‘blank’ seedling tray compartment, to test the soil temperature. A perfect 26-27 degrees when on the Foot Mat and a good 22-24 degrees on the Reptile Mat.

Here is our seedling rack (click on the images to enlarge):

Although I feel more like a carpenter than a gardener with all this building going on, my seedlings are now happy and therefore so am I

Happy gardening
Mark

Popularity: 23% [?]

Related Posts:

• What a difference the right soil can make
• Planting our first seedlings
• Can you start a Square Foot Garden in winter?