Florence Fennel for Beginners, Growing and Harvesting Guide

Last Updated on January 5, 2022 by Real Men Sow

Fennel, also known as Finuccio or Florence Fennel, is a herb that has green leaves and aromatic yellow flowers. It grows tall up to three or four feet. Although being a herb, it is a popular vegetable in the European region. So how do you grow it? Plant it in a well-drained, rich soil that is exposed fully to the sun. Every week during the dry season, water them once or twice. Also, add a general-purpose fertilizer once or twice per season. Fennel

How to Propagate Florence Fennel?

As soon as the ground can be worked on, Fennel seeds are directly sowed into your garden. One-fourth” of soil is covered on the seeds early in the season. The space between the seedlings are 10-12” apart, in rows 18-24” apart. In midsummer, a new planting may be started that is to harvest in Autumn.

How to Sow Florence Fennel

Recommended Varieties: Rondo F1, Romanesco, Orion (Organic Variety).

Sowing Fennel in modular trays indoors is recommended and can be started in mid May and sown until late June.

Guide to Sow Fennel in Modular Trays

A finer-textured and nutrients-lowered seed compost is recommended than a standard multipurpose compost. A seed module tray that has a two inches deep section is also recommended.

Here’s what you do:

  • Fill the seed tray with compost and remove any excess compost off the top. Be sure to remove or break up lumps in the compost. Settle the compost by banging the tray on the table.
  • Create small hollow holes about 1 centimeter deep.
  • Sow one to two seeds per hole. Remove the weaker seedling if the 2 seeds germinate.
  • Cover the seeds with compost again and remove the excess off the top.
  • Gently water the seeds.Weak water is recommended so that the seeds will not move around.
  • A warm place of a temperature of 20 °C is needed for the trays to germinate. In four weeks, they are ready to plant.

If the weather in the springtime is not favorable, pot the modules onto pots with 8 centimeter depressions and leave them in the tunnel or greenhouse. The planting may be delayed by a couple of weeks but the result will definitely be better.

Florence Fennel Seedling Care

Being leggy or long spindly plants is generally avoided when growing seedlings indoors.

Leggy Seedlings.

When seedlings get too much heat and insufficient light, they become leggy. If the seedlings are started off on a windowsill, be sure they get as much daylight as possible. To accomplish this, a makeshift light box made of a sheet of reflective tin foil is placed on the room side of the seedlings. 

If the seedlings are on a heat bench or in a propagator, check if they are spindly. If they are, more light should be given to them and heat should be toned down.


Remove the weaker seedling if two seedlings have germinated in the pots. Nip the seedling with scissors and never pull it out. This might damage the other seedling.

Watering Fennel

On hot days, you will need to water the plants twice a day. When it’s dull, you can water your plants every two days. Be careful to not let the compost completely dry out. This will form a crust on top that will not allow absorption of water the next time it is watered.

Hardening Off the Fennel

Be sure that your plants harden off before they are planted in their final positions.

Before the plants can be moved outside, they need to be used to the outdoor conditions. Depending on the weather, it can be as long as a week to ten days.

The most recommended way to do this is using a cloche or mini greenhouse. Place the cloche during the nights and remove it on dry frost-free days. Increase the time, slowly, with the cloche undone until the week or ten days is done when the cloche is permanently removed.

If the weather is not extreme, a cloche is not needed. The plant can be placed outside everyday with increasing time intervals.

If a windowsill is used to start off the seeds, they will need to be left in an unheated room for at least a day before they can be put outside in a cloche.

Planting out Florence Fennel Seedlings

After four or five weeks and the weather is good, the seedlings can be planted out. Seven weeks is recommended for seedlings that have been potted.

Transfer the plant on a dull day or in the evening to prevent the plant from wilting. Dig a hole about the size of the seedling plug. Push the soil in around the roots and do not firm down on the top of the soil so the moisture won’t be hindered from going to the roots. Water it after planting but do not soak it.

Fennel Crop Care

Water – When the weather is dull, water the plant well to prevent bolting.

Slugs – Slug pellets or slug beer traps can be used to prevent slugs.

Carrot Root Fly – This is an unlikely problem, however, if it is a problem in your garden, it will also affect fennel.

Hoe – To remove weeds that steal water, nutrients, and light that are for your plants.


Fungal disease often happens to congested crops. Be sure to have clear, sufficient space between your crops.

Microbial activity

Hoeing also allows better growth for the plants. When we hoe, we break up the top layer of soil which makes way for air and moisture to circulate better. This will catalyze microbial activity that releases more nutrients for the plants. 

How to Harvest Fennel?

Fennel is ready when the bulbs are about the size of a tennis ball or seven centimeters across. Cut it just under the bulb. Do this to every harvest-able bulb to allow the remaining ones to grow even bigger. The leaves can be harvested at any time while the flower heads can only be harvested when the seeds have formed and the flower head has died. Extract the seeds and store them in a cool and dry location.

Do not harvest them before the first frost. They are resilient plants and can grow even after numerous hard frosts. To elongate the life of harvested fennel, remove the leaves. The leaves can be used to flavor soups, stocks, or stews. Leaves that are left on the plant suck the moisture and will leave the bulb soft.


Real Men Sow
Real Men Sow

Hello, I’m Pete and I’m currently based in the west of Scotland, in a small place called Rosneath, where I’m exploring my garden adventures. I personally started gardening around 6 years ago and initially, I started out by growing my favorite fruits and berries, such as strawberries, Raspberries & Gooseberries. Since then I’ve added a lot of vegetables and working closely with my neighbor, it’s been a lot of fun.