Garden Action

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Onion Pest and Disease (continued - page 3)

Caring For Onions
Check that the onions are receiving a regular supply of rain water - watering may be required in dry periods up until mid August. From then on, do not provide any water, it may delay the maturing process. Weeding will also be necessary, because onion foliage provides no protection against weeds.

Maincrop onion seeds will need to be thinned (reduce the number of seedlings to avoid crowding) when the seedlings reach about 5 cm (2inch). Thin the seedlings to 13cm (5inch) apart. The same applies to Japanese onions. Maincrop onions from sets and Spring onions should need little or no attention other than water and weeding.

How to Harvest Onions
Maincrop and Japanese onions are ready for harvesting a week or two after the foliage starts to turn brown and shrivel up. On a sunny day, ease the onions roots from the soil with a fork and leave the onions to dry in the sun. When dry, remove the foliage at the top and store in a cool, dry and dark place - either in nets or boxes with newspaper to keep the onions separate. Onions with thicker necks should not be put into storage, because they will deteriorate quickly. Maincrop onions  will keep for a couple of months or more in ideal conditions, but Japanese onions will only last a month.  

Spring onions should be harvested when about 45cm (18 inch) high and eaten within a day or so.

Onion Pests and Diseases
Onion Fly
This looks like a normal fly - it lays its eggs in Spring on the neck of the onion, and the developing larvae will tunnel into the onion and destroy it. Hoe around the onions regularly to expose the eggs. The time of greatest risk is when you thin the onions - the flies are attracted by the scent. Growing from onion sets removes the need for thinning and the onions are unlikely to be attacked. 
Click here
to go to GardenAction's main page on onion fly.

Onion Eelworm
Eelworms are microscopic worms in the soil which cause the onions to distort and swell in size. There is really no effective chemical cure, and it will be necessary to stop growing onions in the patch of ground for three to four years. 
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to go to GardenAction's main page on onion eelworm.



Name: jim@GardenAction
Date posted: December 20, 2011 - 04:34 am
Message: The larvae of the leek moth tunnel into the leaves and down into plants causing secondary infection

Name: alemu trlt
Date posted: December 19, 2011 - 02:53 pm
Message: what are the mouth part they have and plant part that are affected by the leek moth?

Name: sankale
Date posted: September 01, 2011 - 04:38 pm
Message: how long does bombay red onions stay in the nursery before transplant?

Name: Harry Jones
E-mail: Private
Date posted: July 13, 2011 - 07:38 am
Message: I am NOT a gardener, I inherited a "veggie plot" when moving here to france, BUT, I have tried over the past four years to grow my own veggies, and have been fairly successful. last year though I tried to onions and shallots for the first time, the leaves had withered, either due to lack of rain, or, because they were ready ????.
I was somewhat disappointed with the results because most of the sets I planted have NOT grown into nice round onions but have come out more like a Garlic corm, (lots of little onions attached to each other, what am I doing wrong ??? should I lift the onion after a short time and seperate these little jobbie, or what ????, I await your response with eager anticipation......

Name: Bethany
E-mail: Private
Date posted: July 09, 2011 - 05:05 pm
Message: I have discovered somthing in my garlic and onion bulbs, its approx. 1-2 mm long, about 8 legs on the front half of the body, opaque enough so that you can see part of the digestive system, short antennie, and a round back end. I am not sure if this bug is eating the bulbs or has arrived after the bulb has started to rot.

Name: jordan
Date posted: June 03, 2011 - 01:54 pm
Message: how long does it take onion seeds to root from the ground?

Name: tracy
Date posted: January 20, 2011 - 12:09 pm
Message: can i grow onions in a pot and if so how big should the pot be?

Name: prasanna b k
E-mail: prasannabkp@gmail.come
Date posted: December 09, 2010 - 06:38 am
Message: sire plz seend onion reviews cultivation

Name: Zuzette
Date posted: October 09, 2010 - 08:42 am
Message: Is it true that you have step on the onionleaves as to flatten it. Our onions seems to grow in the leaves only.