GARDENING Growing food from seed at home

HEAT LOVERS Tomato seeds prefer warmer temperatures.

Growing food from seed at home


Organic growing
Hans Wieland

Growing food from seeds is one of the wonders of gardening. For good seed germination, you need viable seed, the right temperature, and moisture, air and light.
Seeds must be of good quality and not too old. On average most seeds store for two to four years in a cool, dry place. Check the germination information on the package. Seeds should never be left in a hot or damp polytunnel, as they will deteriorate quickly.
Beginners, and sometimes more experienced gardeners, often fail to provide the right temperature for germination. Each crop has an optimum temperature for germination. The average temperature required for most seeds is 16-20°C.  Tomato seeds, for example, like it warm, around 20°C. Too high a temperature can be detrimental to certain crops, however. Lettuce does not germinate well above 24° C. There are different types of heated propagation units available with heating pads or mats with thermostat or soil-warming cables.
Seeds need moisture and air to germinate. The higher the required temperature, the higher is the water uptake – but beware of over-watering the seeds, as it encourages fungal diseases.
Some vegetable seeds, like lettuce and celery, require light to germinate, so they need to be sown shallow. Once germination has occurred, however, all plants require light. Germination on window sills works only to a degree, and plants can often become leggy. A window sill in a warm kitchen is good enough for the first few days, but once seeds have germinated, they need light from above.
Here is where my homemade propagation box comes in. Once built, the box once built can be put up in a polytunnel or conservatory, or outside underneath a glass veranda.

How to make your own propagation box
If you have a polytunnel and want more produce, and in particular early produce, you will need to be able to propagate your own seeds. A home-made propagation box is more economical than buying a prefabricated one. More importantly, you can adapt it to suit your own requirements.
The most important factor is the heating element. As most commercially available heating mats are 1m x 60cm, it is best to build your box around these dimensions or multiples of same (such as 2m x 60cm).
Ideally, use recycled materials like old windows, glass panels, bits and pieces of timber, and insulation you may have lying around like Styrofoam or cork tiles. You will need the following pieces of timber: A baseplate of 120cm x 70cm, or 240cm x 70cm; two sides, 120cm or 240cm long x 25cm high; two sides, 70cm wide x 25cm high; and two triangular gable sides, 70cm at base x 65cm in height. You will also need three 2x4 batons, either 120cm or 240cm long, one to be used as a ridge.

1. Make a rectangular box using the baseplate and four sides.
2. Attach triangular gables to the shorter sides.
3. Connect the top of the gable ends with the ridge baton.
4. Insulate the base with styrofoam or cork tiles etc.
5. Attach the other two 2x4 x 120cm/240cm batons to the outside of the top of each long side to hold the glass panels in place.
6. Cut the glass to fit.
7. Insert your heating element and plug in!

Hans Wieland is joint manager of The Organic Centre, Rossinver, Co Leitrim, which offers courses, training and information in organic growing, and runs an Eco Shop and an online gardening store. For more information, visit www.theorganiccentre.ie, e-mail info@theorganiccentre.ie or phone 071 9854338.
Questions or comments? Contact Hans at living@mayonews.ie.