Harvesting & preparing fennel

A nutritious vegetable, aromatic herb and spice – fennel is a truly versatile crop! Here is a guide to harvesting and storing your own home-grown fennel.

Fennel (Foeniculum vulgare) is cultivated in two forms: as a vegetable or as a herb and spice. Whether cultivated as a bulb, or for stalks or seeds, there are different methods for harvesting, storing and using fennel. In this article you will learn all about when to harvest, how to go about harvesting fennel and store it and what are the health benefits of this Mediterranean vegetable and herb.

When to harvest fennel

Fennel needs plenty of warm weather and sun to grow. In cooler climates, as opposed to warm Mediterranean countries, the plant needs more time to form their tasty bulbs. From sowing to harvesting fennel, it typically takes ten to twelve weeks to get a fist-sized bulb. Up until autumn, you can collect the finely pinnate feathery fronds as a sweet-aromatic culinary herb − enjoy these fresh or dry them gently at 40 °C in the oven. Sowing and planting fennel in succession allows it to be harvested continuously between the end of June and October. Harvest no later than the end of October before the first frost, because fully grown fennel suffers from frostbite at sub-zero temperatures.

To harvest fennel, cut off the bulb about 2 to 3 inches below the soil surface with a sharp knife or garden shears. Alternatively, pull up the entire plant and then trim off the roots.

Can you still harvest fennel after it flowers? If your fennel has formed a flowerhead, it was likely planted too early and it is not a bolt-resistant variety. For more info, read our guide to bolt-resistant and aromatic fennel varieties. The fennel bulb becomes woody when it forms its umbrella-shaped flowers, making it less pleasant for cooking and eating. To avoid this, harvest the fennel bulb as soon as you spot that it is about to flower. Alternatively, you can let the fennel flower and leave the seeds to mature for harvest. To harvest fennel seeds, cut off whole umbels with secateurs early in the morning. Then lay them out to dry out at room temperature for a few days. The dried fennel seeds usually fall off the umbels on their own. You can keep the seeds in a jar, and store them in a dark, cool place for several years. Fennel flowers provide food for lots of beneficial insects and the seeds can be used as a culinary spice and for medicinal purposes.

Storing and freezing fennel

Fresh fennel can be stored in the fridge, wrapped in a damp kitchen towel, for up to two weeks. Storing fennel in damp sand and in a cool location (0 to 5 °C) is also an option if you are short on fridge space. However, storing fennel in sand does make cleaning it more of a chore. To prepare fennel for freezing, finely chop it and blanch it briefly in boiling water. Depending on the size of the pieces, blanching takes 30 seconds to two minutes. Allow the fennel to cool, and then pack it in airtight freezer bags or containers. It keeps in the freezer this way for several months. It is also possible to freeze fennel without blanching it, however, the quick heat treatment extends the fennel’s shelf life and helps preserve the flavours and nutrients longer too.

Preparing and preserving fennel

Before preparing and cooking fennel, it should be cleaned and any areas that are wilted, woody or mushy should be cut out. Preparing fennel bulbs is usually limited to removing the hard stalk. Just cut the fennel bulb in half and carefully trim out the woody parts of the stalk. Some popular dishes include fennel soup or fennel halves roasted in the oven or grilled. In Mediterranean cuisine, fennel is popular in many fennel side dishes.

There are several methods for preserving fennel. The fronds and seeds can be dried and used as a herb, spice or for fennel tea. The highly alcoholic absinthe and France’s national liqueur, pastis, owe their unique taste to fennel seeds. Fennel seeds or leaves go well with pickled vegetables, and they also give baked bread an aromatic hint of spice. The fennel bulbs can be pickled, fermented or preserved. To preserve fennel, cut it into fine strips or chunks before making a pickling brine. Put the fennel pieces into preserving jars and pour the boiling brine over them. Then, seal the jars tightly.

Which parts of the fennel plant are edible? All parts of the fennel plant are edible and safe for humans and animals.

Can I eat raw fennel?

Fennel can be eaten raw. It is delicious served in raw salads or for dipping as a healthy snack, similar to celery (Apium graveolens var. dulce).

Is the stalk of fennel poisonous?

The entire fennel plant is edible, and no part of the plant is poisonous. This means that even the fennel stalk is edible.

How healthy is fennel?

Fennel has few calories and high fibre content. The bulbs are an especially good source of iron and potassium. Other valuable ingredients include high levels of vitamins A, B, C and E. Fennel also contains many essential oils such as anethole − anethole gives fennel an aniseed flavour (Pimpinella anisum). With all its minerals, vitamins and essential oils, fennel is an extremely healthy and wholesome vegetable that fits many diets.

Fennel health benefits

The healing effects and health benefits of fennel lie mainly in its ability to aid digestion. It can be used to ease flatulence, stomach pain, cramps and diarrhea as well as calm respiratory ailments such as coughs and bronchitis. Fennel can even be used medicinally for children. A little fennel tea is particularly suitable for babies and toddlers, which they welcome thanks to its sweet taste. The daily dose for tea is about 7.5 g of fennel seeds. Alternatively, fennel honey – a mixture of honey and bitter fennel oil – can be used for older children.

In addition to easing gastrointestinal problems, fennel can also have a calming effect. Among other things, it can soothe pregnancy pains, kidney stones, gout and eye inflammation.

A close relative of fennel, often found growing together, is caraway (Carum carvi). Here you can learn all about the benefits of caraway as a spice and medicinal plant as well as how to grow your own.