# Preparing For Onion Season

- Link: https://rd2.co.nz/preparing-for-onion-season/
- Published: 2022-05-10T01:27:14+00:00
- Author: RSF Admin

Onions are one of [New Zealand’s most lucrative vegetable exports](https://www.onionsnz.com/).
Yielding over 200,000 tonnes per year, about 90% is sold overseas. The next growing
season is about to begin, so let’s look at how growers can ensure a healthy crop.

## New Zealand onion growing season

With winter fast approaching, it’s almost time to begin onion seeding. The correct
time to plant onion crops varies depending on the region, which can begin as early
as May. Crops should all be in the ground no later than September. 

Onions are ‘photothermoperiodic’, meaning temperature and daylight play a significant
role in the quality of yields. Onion seeds ideally germinate at temperatures in 
the low to mid twenties celsius. Dramatic fluctuations in temperature can result
in onions bolting to seed, producing flowers and seeds rather than a bulb. 

The number of daylight hours that onions are exposed to is also a determining factor
in when bulbs develop, which varies between onion varieties.

## Preparing your soil

The soil needs to be well conditioned and nutriated, as well as have good drainage.
Our humic acid product, [Humax](https://rd2.co.nz/?s=humax&post_type=product), is
an excellent option to condition your soil. It can provide stability, which improves
drainage, and allows for better uptake and retention of nutrients and water.

Onions have a notoriously difficult time taking up nutrients due to their shallow
roots. Our [Rootella](https://rd2.co.nz/?s=rootella&post_type=product) line of Mycorrhizal
fungi form a network of thin fungal strands that attach to roots and increase their
effective range. This increases a crop’s ability to uptake nutrients and also contributes
to soil stability. One of the major benefits of Mycorrhizal fungi inoculation is
the ability of the organism to scavenge and uptake phosphorus in particular, and
also nitrogen. This alleviates mineral loss to waterways which can affect our environment
and importantly reduces the need to apply expensive Phosphorus fertiliser, which
has dramatically increased in price.

![green plant on brown soil](https://rd2.co.nz/wp-content/uploads/2022/05/a388hsbgd9a-
1024x683.jpg "Preparing For Onion Season 1")

## Fertilising your onions

Before applying any fertiliser to the ground, it’s important to know where your 
soil’s nutrient levels stand. Conducting an initial soil test will help you understand
what nutrients will be needed. Overapplying nutrients can be as detrimental as mineral
nutrient deficiencies. Excesses of elements can retard quality, cause environmental
issues in our waterways and also cause lockup of other minerals. The utilisation
of [Mobilizer](https://rd2.co.nz/product/mobilizer/) at key periods such as planting
or before bulbing can unlock locked up soil minerals making them available to the
crop.

### Macronutrients

Onions need all macronutrients. Early applications of phosphorus help stimulate 
root growth and establish the crop. Nitrogen is also important for high yields, 
though over-applying it can affect the maturity of the bulbs. Potassium assists 
in maintaining good yields and the accumulation of sugars in the bulbs. Try our 
[Synergizer](https://rd2.co.nz/product/synergizer/) product for balanced NPK needs.

Sulphur is also very important in onion growing. S has been found not only to increase
the bulb yield and dry matter but also improve onion quality especially pungency
and flavors.

### Micronutrients

Micronutrients, while needed in smaller quantities, also play a critical part in
producing a healthy quality yield. Studies into micronutrient removal rates by onions
show that boron and iron are particularly important. Added to this, [Magnesium](https://rd2.co.nz/product/biomin-magnesium-organic-mineral-fertiliser/)
and [Zinc](https://rd2.co.nz/product/biomin-zinc-organic-mineral-fertiliser/) have
also been found to positively affect the size and quality of onion crops. 

Our [Biomin Booster V](https://rd2.co.nz/product/biomin-booster-v-organic-trace-mineral-fertiliser/)
trace mineral fertiliser provides an ideal solution to help your crops achieve a
good balance of all micronutrients. 

If you have questions, send me an email – [rsf@rd2.co.nz](https://rd2.co.nz/preparing-for-onion-season/rsf@rd2.co.nz)