Welcome to the wonderfully weird world of celeriac. It is definitely not a pretty looking vegetable, it always reminds me of a mandrake root from Harry Potter. Celeriac is generally not that popular in North America and the only place you will generally come across it is in a fancy restaurant. This is a shame as this vegetable has so much to offer.
Disclosure: Some of the links below are affiliate links, meaning, at no additional cost to you, I will earn a commission if you click through and make a purchase.
My goal is to make some delicious celeriac remoulade or celeriac and potato puree with plants grown in my own garden. There is something very fulfilling when you can go from garden to table. Not to mention the peace of mind of knowing exactly where your food is coming from and what happened (or didn’t) throughout its growing time.
What is Celeriac?
Celeriac (Apium graveolens var. rapaceum), originated in the Mediterranean Basin. It is often called celery root and it is a cool-season vegetable. In its natural state is a biennial, but it is more commonly grown as an annual. It is a variety of celery that has been cultivated for its edible stem. You may be inclined to assume it is a root vegetable and it would be an understandable mistake.
What seems to be the root is actually a bulbous hypocotyl. It can be eaten either raw or cooked and it tastes generally like celery but with a nutty mild spiciness. It can be roasted, stewed or mashed, and is often used in soups.
Types of celeriac
There are quite a few different cultivars of celeriac and I have listed some of them below with their expected days until to maturity.
- Giant Prague – 120 days (This is the one I am growing)
- Monarch – 110 days
- Diamant – 100 days
- Prinz – 105 days
- Alabaster – 120 days
Health benefits of celeriac
It may be ugly but it’s definitely good for you! Celeriac is a bit of a nutritional powerhouse, that is jam packed with vitamins (B6, C, and K) as well as fiber. As if that wasn’t enough it is also a good source of important minerals (manganese, potassium, and phosphorus) and antioxidants.
Growing celeriac from seeds
Celeriac will not be rushed for anyone. So if you want to grow this vegetable then planning is key! It grows best when the seeds are started indoors about 10 weeks before the last frost date. This will ensure that you give it enough time to get moving.
The seeds are known to have a low germination rate (~50%), so make sure to sow multiple seeds in each cell. These 72-cell seed starting trays are perfect for getting all your seedlings ready. Fill each cell with soil or even better an organic seedling starting potting mix and gently press the celeriac seeds into the soil. The seeds should ideally only be 1/8″ deep in the soil.
Celeriac seeds like a temperature of about 70-75F in order to germinate, and given their aforementioned low germination rate you will want to use a germination heat mat to give them their best shot. All being well you should see your seeds starting to sprout within 14-21 days. After the seeds have sprouted you will want to continue growing them in a cool location (60-70F) and thin to one plant per cell.
Growing season for celeriac
Celeriac grows best when the nights are cool. In areas where the winters are cold (like me in Canada) you will want to grow celeriac in the spring. Conversely, if your winters are warm then you will want to start growing your celeriac in late summer. If you live in an area with a long growing season (Zone 7 or warmer), then you can directly seed into the garden in late summer for a second harvest.
Growing celeriac in the garden
Once the last frost date has passed and your celeriac seedlings have reached 4″ in height then they can be moved out into the garden. But like with any seedlings started indoors you will need to make sure that you harden off your seedlings first. Once this is done, then they should be planted 6-8″ apart and the rows should not be closer than 14″. Be sure that you do not bury the crowns of the plants. It is common for the seedlings to be planted in 3-4″ deep trenches. This allows for the soil to be “hilled-up” around the hypocotyl as they grow.
Growing celeriac in containers/pots
While it is possible to grow celeriac in pots it is not a situation that let’s it thrive. For a single plant, the pot should be at least 8″ in diameter.
Pests and diseases
This is one serious plus for growing celeriac as it really doesn’t have any garden pests or serious diseases that you need to worry about. On occasion, you may run into some issues with slugs on young plants.
Sun vs shade?
Celeriac definitely prefers full sun but it does have the ability to handle a little bit of shade.
Caring for celeriac
It is not a high maintenance plant by any means. You will just need to make sure that you keep the planting beds weed-free (which is good practice for any plants) to make sure that weeds are not using up your soil nutrients and water. As the roots of celeriac are so shallow be gentle with your weeding and avoid disturbing the plants. As the hypocotyl grows you will want to carefully snip off any side roots and keep it trimmed to 3-5 stalks so that the crown is exposed. This will help to encourage the growth of the hypocotyl. It is also important to “hill up” the soil around the hypocotyl in order to blanch it.
What soil type is best for celeriac?
Celeriac will thrive in soil with a pH of 6.0 – 7.0 that is well-draining and rich in organic matter. A great way to ensure that you have enough organic matter is to create your own compost. If you have your own compost heap or bin then congratulation. If you don’t there is no reason to worry as it is super easy to get started composting! Check out my post on how to compost like a pro.
How much watering does celeriac need?
As it is a shallow rooter watering properly is very important. If there is a shortage in water then the plant will stop growing and that is definitely not what we are after. Ideally, you want to make sure that the top few inches of soil are kept moist all the time.
As with most plants, there are certain pairings (companion planting) that work well and others that do not. In the case of celeriac, it is going to thrive when planted alongside spinach, peas, and spinach. You will, however, want to keep it away from squash and cucumbers.
When to harvest celeriac?
As we know, celeriac is slow and it takes about 90-120 days for it to reach maturity. It is best if it is harvested in cool weather. The hypocotyl should be harvested when it reaches a size of about 10-14cm in diameter. When it is ready to harvest you will want to cut the stems very close to the hypocotyl and then use a garden fork to remove it. This is definitely a handy garden tool to have around as you can also use it to harvest potatoes and turn your compost pile. if you wait to harvest your celeriac until after a light frost you will find that it increases in flavour. Don’t wait too long as it needs to be out of the ground before it freezes.
Celeriac typically can be stored as it is not allowed to dry out and it is kept at 0C – 5C (32F – 41F). It is important to make sure that you remove any of the thinner stems around the base. If they are left attached then the hypocotyl can be prone to rotting from the inside out. In the refrigerator, it can last about 1-2 weeks if it is kept in the crisper and wrapped in plastic.
Another alternative is to freeze your celeriac, this is easy to do and it keeps well. As an added bonus it will be ready to grab from the freezer and toss into your stew or soup. if you want to freeze it then you will need to wash, peel and cube it first. I like to lay mine out on a cookie sheet and place that right into the freezer. Once it is frozen you can move it into a freezer bag or better yet, use a vacuum sealer (this is the one I have and I love it) to keep it freshest.