Friday, 14 March 2008


Recently on KGI the topic of day length in regards to vegetable (and other plants) growth was brought up and I thought I would discuss it a bit here too.

Why plants grow and produce their crop (of whatever - leaves, fruits, seeds, tubers etc) is affected, we all know, by the temperature of the soil and air, water and nutrient requirements and amounts of direct sunlight. There is another factor that we often forget to consider and that is day length. At the equator, for example, the day is the same length all year round and that is why they can grow some vegetables all year round and other, equally warm and humid places cannot.

Sometimes a variety of a vegetable, for example the Burnley tomato which people are planting even now, in South Australia, will say in the information "late maturing". What this really means (and I wish they would say on the label to make it clear) is that this tomato is daylength sensitive and grows better as the days shorten (as opposed to regular tomatoes that are day length neutral and can be kept going in a glass-house for months.) Often you see this on onion labels and seed packets - early maturing or late maturing. What it means is how the plant responds to day length. An onion planted without taking this into account will not form a nice, fat bulb but, instead, run straight to seed or just get a thick stem and no bulb.

No doubt there are tables online somewhere with lists of plants such as the onion family, that have day length requirements - but on a short so-journ into etherland I couldn't find anything really comprehensive. There is, however, an interesting article here.

Of course we all know that every land animal that I can think of responds to day length too!

I love it when the days get short and I have the fire on and I can see the sun setting and casting a beautiful, soft glow over the hills around me. The very tips of the gum trees at the top of my driveway catch the last rays of the winter sun and turn awe-inspiring shades of red and yellow. Yesterday on the radio I was listening to a bloke talking about the positive health effects of taking time to experience something natural, in our lives. It is so true. The dew on a leaf or on a spider web, the shield bug that Maggie photographed recently, the rustling of the wind in the trees and the sounds of birds in your garden or waves on the shore - all things to give you that deep sense of well-being and restore balance and energize you.....I have wandered away from day length in an abominable way!

1 comment:

Tracy said...

Hi Kate. In answer to your question on my blog, a SAHM is a stay at home mother.

I think I am suffering a bit from the long day lengths and the heat at the moment. I also prefer the shorter, cooler days and longer nights.