My Secret Trick for Starting Seeds on the Cheap!

Do you have a small greenhouse and wanting to start all sorts of seeds for your summer garden? Want to stuff that greenhouse full of veggies and flower starts.. without spending a fortune on heating?

Here is a tip I learned years ago (at a greenhouse I worked at) that I have been using ever since for my own wee organic greenhouse biz. This trick is effective and inexpensive, allows me to start thousands of seeds quickly.. if I want that many. You can also use it to give your dahlias, cannas, and potted plants a head start to have flourishing plants when you pop them out at the end of May.

Gutter cables work like a charm for starting hundreds of seeds at a time.

Heated gutter cables. Yep, that is my trick. They come in several lengths, are safe to use for months on end, cost just pennies a day, are easy to use.

Gutter cables, aka de-icing cables, are designed to be used in metal or plastic gutters, are water proof, super safe, and inexpensive, as opposed to heating all the air in the greenhouse with a portable heater.

Seeds benefit from bottom heat to germinate well and quickly, plus this will keeps your seedlings happy in a cool greenhouse, too, as they are sitting on warmth even if the air temp is in the single digits (Celsius).

I leave the cables on night and day, for months at a time, till I feel it is warm enough in the greenhouse that they no longer need it. If you want less heat, just have less cable underneath that particular tray or plant.

This layout of the cables was not the best, though it worked.

The first year I used the cables in my own greenhouse, I just placed them on the table, squished the gutter clips in between the boards to sorta pin the cable down, popped some wooden stakes onto the tables to keep the trays off the cables ...and it worked a charm.

However, the cable and boards kept moving around, it was all a bit of a fuss to deal with, and see how the cable goes over the lip of the table? That is a wasted heat opportunity.

The following year, hubs screwed in some boards onto 2 of our tables, to hold the trays just above the cables for evenly spread bottom heat.

We pushed the 2 four foot tables together for absolutely loads of room to start a dozen, or more, seed trays at the same time.

We then ran the cables lengthwise rather than widthwise and it worked so much better. No more movement all over the place, the cables stayed in place nicely.

Put your trays on the cables whichever way they fit best....I grew thousands of seedlings on these cables each year.

Geranium cuttings on bottom heat in the late winter greenhouse.

Place seeds, seedlings, and cuttings on top of the boards, above the cables. The heat is spread nicely and evenly underneath the trays.

I also use this for starting my dahlias - pot them into 2 gallon pots, place on the cables, they grow so much quicker. You can even take cuttings from the new growth and 'make' more dahlias. This works for cannas and perennials, anything you want to get a head start with.

In Year 4, we removed those spacer boards as they made the tables hard to use effectively the rest of the season. You can see how I spaced out the cables in the picture above.

Gutter cables are 100% safe. They never get so warm that they would melt or burn anything. You can take the cable and hold it in your hand, it is just pleasantly warm to the touch.

Cover with plastic to easily, and inexpensively, retain humidity and heat. I would often place the tray of seeds or cuttings right inside the plastic bag and fold it closed. Another great trick I learned while working at that greenhouse ; )

Check on them daily and shake off the condensation to prevent damping off and rot. Take them out of the bag as soon as they germinate, just like you would with a humidity dome.

This here is the super high tech garden product that I use as a humidity dome ;)

I used the gutter cables for 14 years to start my seeds and plants at my wee ngp greenhouse business. Now, I need to find those cables in the moving boxes so that I can set things up again at this new house, in my new greenhouse. They last forever, are pretty indestructible!

I will have to find new tables/benches and figure out how to pin the cables in place on those, but one thing is certain... cables are way cheaper than heating mats.

Hope this trick helps you as much as it did me! You do not need fancy or expensive to grow great plants : )

Happy Sowing & Growing ~ Tanja