Tuesday, September 13, 2011

Growing onions successfully

Onions are a vegetable that do very well at La Pasera in spite of the heavy clay soil we have and the high humidity we tend to experience in June and July. The heavy soil does not allow us to sow seeds directly onto the soil in September as many of the locals will be doing in the next two weeks. These seedlings will grow over the Winter months and will be planted in their permanent position in early Spring.

At La Pasera, we prepare the soil by digging it over and incorporate organic matter and compost that we have produced during the previous 12 months. This will help to break up the clay and provide a valuable source of organic matter that will help towards increasing the water retention capabilities of the soil and increase the fertility.

As the soil warms up with the arrival of Spring, we will purchase 400 onion plants including red, white and early ones from a local grower that has a vegetable plant stall at the local market held on Wednesdays in Town. We plant the onion seedlings in a way that gives them a very good start and ensures they grow strong and healthy to be able to stand better when the humidity levels are persistently high. For this we will open a drill on the ground, about 3 inches deep, to which we will add a good amount of very well rotter manure. Once the manure is put along the drill we water well the soil before gently pressing the onion root ball and small bulb into the wet, well rotted manure, this helps the roots to settle in. At this stage the onions are resting on the ground at an angle and about 10 to 15 cm apart. Once completed we back-fill the drill with soil and wait a few days before we see the onions are starting to grow straight.

The day we plant the onions is the only day we water them as onions are a crop that require very little if any watering other than the water they get when it rains. As the onions grow we weed them regularly to remove any weeds that will be competing with the onions for water and nutrients. Hoeing the soil also keeps the soil nice and loose. Care should be taken not to cut the onions as they will not sprout again.

Up to now we have found onions to be a trouble free crop and crop rotation does help to prevent soil borne diseases. With a watchful eye you can remove the occasional pest that may graze on the young onion leaves.
By June the early onions are ready to start harvesting. Something that surprises me is how mush sweeter home grown onions are than those we purchase from shops.

This year we sprayed the onions during the high humidity period with a horse tail spray we made ourselves as it is a good organic way to control fungal diseases that proliferate with high atmospheric humidity.
By the early July the onion bulbs are swelling up above ground and the leaves are staring to die back mainly due to the fungal infestation that the horse tail has helped to slow down. Onions should normally continue to grow in the ground well into August. We find that if we get the onions big enough by early July, it does not matter if they are cropped a few weeks earlier than expected. The onions are walked over to knock the stalks down so that they stop growing and they are left on the ground for a couple of days providing that it does not rain otherwise they get brought in and left to dry in a dry and well ventilated area. Once all the leaves are brown and dry the onions get strung before we hang then up in the loft where they will enjoy the rising hot air on the days we are working in the workshop with the wood burner on. This heat seems to ensure the onions last well for months.

This year it was early May when we ate the last of the onions we harvested the previous July. Needless to say that a few always sprout. In time we hope the structure of our soil will be good enough to be able to grow our own onions from seeds.


  1. That´s a lot of onion starts. These are just for the 2 of you?

    And I have acute cart-and-pony envy!

  2. Hi Coco - we do use a lot of onions both for cooking and for making onion marmalade. We also give a few to family and friends so with careful planning we can have onions for the full year.


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