Horseradish is an easy plant to grow even though it takes a good 12 months for the roots to get big enough to harvest. It also tastes its best after a year of growth. But when exactly should you harvest horseradish from your vegetable garden, and how should you go about it?
There is some debate about when to harvest horseradish. Some gardeners and commercial growers maintain it’s essential to harvest horseradish in late fall. Others say that the best time to harvest is in early spring before the weather gets hot. Most agree that horseradish roots harvested in summer have an unpleasant taste.
How Do You Know When Your Horseradish Is Ready to Harvest?
Most home gardeners grow common horseradish, which is the tastiest type. Bohemian horseradish is resistant to diseases like mosaic and white rust but lacks the yield and root quality of the common type.
In its Essential Guide to HORSERADISH, the Herb Society of America states that horseradish grows very well in cooler temperatures.
In warm climates, it will grow in full sun, but only if it gets some afternoon shade. And if it’s hot, it will need regular watering throughout the summer months.
But whatever your climate, it’s best to harvest horseradish when the plant is dormant. This will be before the plants start growing in spring or early winter when they stop growing.
It takes about a year for horseradish to produce roots worth harvesting. So, it stands to reason that you can harvest the roots about 12 months after you planted crown or root cuttings.
If you planted horseradish in early spring, it will be ready the following spring. The same applies to root cuttings planted in the fall – they will be ready the next fall or in early winter in warmer areas.
If you plant your horseradish in spring and want to harvest in the fall, you will need to wait 18 months before harvesting. Don’t be tempted to harvest it in the summer months because it won’t taste great – probably because this is its greatest growth period.
You can judge that your horseradish is ready to harvest by the size of the crown. In early spring you will be able to see the green crown showing as it starts to grow, and it should be about an inch (25 mm) in diameter.
If you harvest in late fall, wait for the leaves to die after frost and for the crown to freeze. According to the Utah State University Extension, horseradish harvested after several touches of frost have a better flavor.
What Happens If You Leave Horseradish in the Ground Too Long?
Horseradish is a hardy perennial herb that keeps growing year after year after you have planted the root. It doesn’t take long for horseradish to start to spread, and once it gets established it can be difficult to get rid of.
This is because all the little roots on either side of the main taproot that we harvest will grow into a new plant if given a chance.
This might be good news for home gardeners who enjoy growing horseradish and making horseradish sauces. But you will still need to keep your horseradish under control.
Even if you want to continue growing horseradish in your vegetable garden, it’s not advisable to leave plants in the ground for more than a year. Apart from taking over your veggie beds, the root will become tough and it won’t taste very pleasant.
Even though it is perennial, as the Herb Society of America points out, horseradish is often grown as an annual, especially when it is grown commercially. Growers remove the entire root at or after harvesting.
The thing is that you can replant side roots and they will develop deliciously tangy taproots of their own.
At the same time, if you live in a cool climate, and the ground freezes, you can leave your horseradish to overwinter. Then in spring, before your horseradish plants start to grow again, you can dig them out.
If you are going to maintain an ongoing horseradish crop, the ideal is to harvest every spring and fall.
How to Harvest Horseradish?
If you harvest horseradish in the fall and there is no frost to kill off the tops of the plants, remove these yourself. Cut the foliage about an inch (25 mm) above the crown and as close to the surface of the soil as possible.
The Oregon State University College of Agricultural Sciences recommends allowing several days between removing the leaves and harvesting. So, after a few days, start harvesting the roots by loosening the soil around each plant using a spade or garden fork.
Work carefully around the main taproot, removing the soil from the side roots as well. It’s the large central taproot that you will eat and/or store.
Propagating Horseradish When You Harvest
Following the advice given in the section above, dig out all the roots. Keep enough small side roots with buds to replant. They should be about the thickness of a pencil.
The University of Minnesota Extension recommends cutting the small roots straight across the tops and at an angle at the bottom. This will help you identify top from bottom when you plant them for the next season.
You can also propagate new plants by cutting sections of the crown and planting them. These should include a few upper leaves of the plant and at least one bud.
If you harvest horseradish roots in the fall, you can leave some healthy, side roots in the soil if you wish. But it’s advisable to harvest these the following spring before the plants start growing again and the taproots get tough.
Should You Wash Horseradish after Harvesting?
Sometimes people store horseradish roots in damp sand or sawdust in a root cellar, in which case there’s no point in washing it first. You can just wipe off the dirt residue.
Otherwise, wash the roots under running water and scrub off the dirt. Dry them thoroughly before storing them.
Can You Eat Horseradish Immediately after Harvesting?
You can eat horseradish immediately after you have harvested it. But you will need to process it first.
Grating horseradish that has been peeled is a quick, easy, and common way to prepare it for immediate use. But it loses its pungency quite quickly, so only grate as much as you need.
That said, if you want mild horseradish, add a bit of white wine vinegar or lemon juice.
Alternatively, you can preserve the grated root in vinegar, and then use this prepared horseradish for soups or sauces.
All you do is peel the roots and then grate them into white wine vinegar. Don’t use cider vinegar because it tends to make the horseradish turn brown very quickly.
Bottle and cap the horseradish and vinegar as quickly as possible and keep it in the refrigerator to preserve its flavor. It will keep for a couple of weeks, or you can freeze it.
You can use a food processor if you want to make a creamy horseradish sauce.
A quick word of warning: as soon as you cut into the skin of the horseradish root, it releases chemical fumes that can make your eyes water. So treat it with care.
What to Do With Horseradish You Don’t Eat Immediately after Harvesting
As mentioned above, you can process horseradish and pickle it in wine vinegar to preserve it for a few weeks. You can also freeze this prepared vinegar.
You can store roots that have not been processed or prepared in a perforated plastic bag in the veggie bin of your refrigerator for two or three months.
If you have a root store or even a cool, dark basement area you can store harvested horseradish for 10 to 12 months out of the fridge. But you will need to be sure that the temperature stays at 30-32°F (-1 to 0°C).
High relative humidity of about 90-95% is also important to minimize any deterioration during this time. Additionally, if the roots are exposed to light while they are in storage, they may turn green. So you should keep them in an area that is always dark.
The secret is to keep checking on your horseradish while you are storing it.
Growing horseradish is easy and rewarding. Even if you neglect it, it will usually thrive.
You can grow a whole bed of horseradish in your vegetable garden or just plant a handful of roots. You will find that it’s easier to grow the roots than to prevent them from spreading!
Harvesting horseradish is also fairly simple. All you do is dig out the roots without damaging the taproot and side roots you want to plant for the next season’s crop.
We generally harvest horseradish early in spring or late in the fall. And identifying when your horseradish is ready to harvest is a cinch.
We have designed these garden tips to make it as easy as possible for you to harvest your horseradish crop the best way, at the right time. Follow them carefully and your efforts will be rewarded.
Even if you have never planted horseradish before and have no idea of what’s involved when it comes to harvesting, these tips will come to your rescue.