When to plant seeds

An old tradition for knowing when to plant your vegetable seeds

In the days before there was a supermarket in every town, many people had to grow their own vegetables and it was very important that they grew well, or the family would go short of food. A whole lot of rather strange traditions grew up as to how to get the best results. This is one of the best:-

"The soil needs to have warmed up to a certain temperature in Spring before seed are planted or they will not germinate well. Farmers were supposed to take off their trousers and sit on the ground with their bare bottoms. If the soil was too cold to do that, then they would wait and try again when the weather warmed up a bit! When it was warm enough to sit on the earth, then it was also warm enough for the seeds to grow."There is a lot of truth in this old tale, seeds will only germinate when the conditions are perfect. These conditions will vary from plant to plant, but typically factors like soil moisture and sustained increases in soil temperature are important. Scientists talk of 'Accumulated Temperature' to refer to the way that in long spells of warm weather the background temperature of the soil increases.

Do you like swimming in the sea? If you go to the beach in the early Summer, the sea can still be pretty cold - even on a really hot day. This is because the air can warm up a lot faster than the water (water has a higher Specific Heat Capacity) than air. If the air continues to be warm day after day, then eventually the sea warms up - so it is nice to swim in by mid to late Summer.The soil is a bit like the sea in this way (remember a lot of the volume of soil is made up of water too!) Only after a long period of warm weather will the soil warm up to the point that seeds can germinate.That's the science of it anyway - but you can also try sitting on the soil with no trousers!!