Horseradish (Armoracia rusticana)How well established is this crop?
Initial trial plantings of these crops may have been done. There is little information on plant suitability to the region and no current information on markets, commercial returns or current research. This is a new crop.Background
Horseradish is a prolific perennial easily overcrowding even the hardiest of weeds. It is such an easy vegetable to grow you are almost guaranteed a crop every year.
The chemical group that gives horseradish its bite and nose clearing characteristic are called ‘isothyocyanates’. As well as a condiment for things such as roast beef, horseradish has been used for a variety of medical benefits such as treating coughs and colds.
Horseradish grows in a wide range of climates and soil types all over the world. To get good yields however it needs a good soil type and water will ensure quality harvests.Winter Chilling and Frosts
Horseradish over-winters as a root beneath the soil surface and only emerges in the spring. Late frosts will affect the foliage. There is no cost effective way of preventing this but the plants recover and continue to grow.Rainfall and Irrigation
Horseradish does best if the roots are kept moist with a combination of rainfall and irrigation. Overhead watering is the best method for this crop as it is grown on a broad acre scale.Wind
Horseradish can be grown in a small or large block. In both situations there is no benefit from wind protection.Soil
The key physical requirement of the soil for horseradish growing is a free draining root zone with a very friable soil. You harvest the roots and clay soils may lead to breakages and a reduced crop. Some growers constrict the roots of Horseradish as it can be invasive.Fertility
To get a good crop from horseradish, soil fertility needs to be high. Applications of a general NPK fertiliser is recommended before planting. Aim for a slightly acidic soil as the plants do like this.Weed Control
When planting root pieces weed control is recommended. After establishment horseradish will out compete most weeds.Pests and Diseases
Horseradish is susceptible to white butterfly. Like other brassicas it also gets club-root if grown in the same soil year after year. Stems are also susceptible to sclerotinia, which shows up as white growth around the base of the petiole. All these problems are easily controlled with common pesticides, and crop rotation patterns.Layout
Using root pieces is the best way to establish a crop of horseradish. They can be chopped up and spread around the soil at a density of around 5-10 pieces m2.
Once the crop has been harvested, small root pieces that drop off will allow the crop to re-grow in the same soil.
After crop establishment little is needed apart from water.Harvest
Harvesting horseradish means digging the plants out of the soil. Once dug, the excess soil needs to be washed off and then the roots need to be chilled before sale or further processing.
When planted in the spring, Horseradish can be harvested in the autumn of the first year. A second method is to leave horseradish in the bed year round, picking roots as you need them.
After preparing the ground and planting, most work on a horseradish block will be done mechanically. This means requirements for a tractor, harvest machinery, bins, cool-stores etc.
It is very difficult to estimate returns for New Zealand grown horseradish. The key to success would be to process the roots on-farm into paste or sauce and package it suitable for sale. This maximises the returns back to the grower. A trip to a local supermarket to find sauce makers may also open up another market, if on-farm processing proves too difficult.Contacts
New Zealand Vegetable & Potato Growers Federation (Inc)
PO Box 10232
Phone 04 472 3795 Grower Freephone: 0800 2 VEGFED (283433)
Fax: 04 471 2861