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Fennel germination time


How to Grow Fennel

Fennel (Foeniculum vulgare) is a perennial herb grown both for culinary purposes and for its ornamental value. Its feathery, branching, aromatic, yellow-green foliage and tall stature can be attractive as border plantings, in cottage gardens, and more. It is also a good choice for butterfly gardens, as swallowtail caterpillars use it as a food source and pupal site. The plant sports small yellow flowers in the summertime, followed by aromatic seeds that can be harvested along with the foliage. It has a flavor similar to anise or licorice. Fennel is typically planted in the spring, and it has a fast growth rate.

Common Name Fennel, sweet fennel, common fennel
Botanical Name Foeniculum vulgare
Family Apiaceae
Plant Type Perennial, herb
Size 4–6 feet tall, 1. 5–3 ft. wide
Sun Exposure Full sun
Soil Type Moist, well-drained
Soil pH Acidic (5.5–6.8)
Bloom Time Summer
Hardiness Zones 4–9 (USDA)
Native Area Mediterranean

How to Plant Fennel

When to Plant

Plant fennel in the spring after the threat of frost has passed. It takes between 60 and 90 days for most fennel varieties to mature. 

Selecting a Planting Site

A sunny planting site with good soil drainage is key. Besides planting in the garden, raised beds and containers also are options. Fennel should not be planted in the same area as dill or coriander, as cross-pollination can occur and affect the flavor of the seeds. In addition, be sure to take the fennel variety's mature size into account at planting time, so it doesn't shade nearby plants. Also, it can inhibit the growth of tomatoes and beans, so avoid planting near either of those crops.

Spacing, Depth, and Support

Plant seeds roughly 1/4 to 1/2 inch deep, and plant nursery starts at the same depth they were growing in their previous pot. Plants should be spaced around 6 to 12 inches apart, and they typically won't need a support structure.

Fennel Plant Care

Light

Fennel prefers full sunlight, meaning at least six hours of direct sun on most days. Shady conditions will make it leggy and floppy.

Soil

Plant fennel in moist, fertile, well-drained soil. It prefers a slightly acidic soil pH.

Water

Fennel likes evenly moist but not soggy soil. Water whenever the soil feels dry about an inch down, but don’t allow the plant to become waterlogged.

Temperature and Humidity

Fennel is a perennial plant within its growing zones, but gardeners outside of its zones often grow it as an annual. The plant is sensitive to frost and cold temperatures. Plus, hot and dry conditions can cause it to bolt and go to seed. Gardeners in mild climates are sometimes able to plant in the late summer for a fall harvest as long as the temperature remains fairly warm. The plant grows best in temperatures between 60 and 70 degrees Fahrenheit and in moderate humidity levels. 

Fertilizer

Fennel generally doesn't need fertilizer. But it will appreciate compost worked into the soil at the time of planting, along with a layer of compost added around its base every few months during the growing season.

Pollination

Fennel plants are self-pollinators.

The Spruce / Michelle Becker

The Spruce / Michelle Becker

The Spruce / Michelle Becker

The Spruce / Michelle Becker

Types of Fennel

There are two main types of fennel to grow in your garden, depending on how you plan to use it. Florence fennel (Foeniculum vulgare var.  azoricum) is used more like a vegetable, grown for its bulbous stem. The main species plant, common or herb fennel, doesn't produce much of a bulb and is typically grown for its foliage.

Florence fennel cultivars include:

Herb fennel varieties include:

Fennel vs. Dill

At first glance, fennel and dill foliage can look quite similar. The leaves are feathery, bright yellow-green, and branching. However, fennel leaves tend to be longer than those of dill. And the herbs have distinct flavors. 

Harvesting Fennel

Harvest fennel leaves as needed throughout the growing season for fresh use. It's used in both raw and cooked dishes. Frequent harvesting will promote a bushier growth habit and consequently more harvestable foliage. But don't trim off more than a third of the plant at once. Bulbs can be harvested as soon as the base of the stem becomes swollen. Pull up the plants, and store the bulbs unwashed in the refrigerator for up to five days before use.

How to Grow Fennel in Pots

You can easily grow fennel in containers. In fact, this can be a good option to prevent the plant from self-seeding in your garden where you don't want it. The container should be at least 10 inches deep with a similar width, and it should have drainage holes. An unglazed clay container is ideal to allow excess soil moisture to escape through its walls.

Pruning

If you wish, you can pinch off flowers as they appear to prevent the plant from going to seed. This keeps the foliage growing and tasting its best for as long as possible. It also stops the plant from freely self-seeding in your garden. However, if you want the seeds for harvesting or self-seeding, allow the flowers to bloom.

Propagating Fennel

Fennel has a long taproot and thus doesn't divide very easily. The better method is to propagate by seeds. This is both an easy and inexpensive way to get new plants, especially if you live where fennel can only be grown as an annual. Here's how:

  1. Watch for seed heads to form on a mature fennel plant at the end of its growing season.
  2. Shake the heads over a sheet or tarp to collect the seeds within.
  3. Spread the seeds in a single layer in a cool, dark, dry spot to fully dry them for a week or two.
  4. Store the seeds in an airtight labeled container, and plant them in the garden the following spring.

How to Grow Fennel From Seed

Soak seeds in water for a day or two prior to planting to speed up germination. Fennel seeds direct sown in the garden will germinate in a week or two. Keep the soil evenly moist but not soggy as you wait for germination. Seeds also can be started indoors about four weeks before your last projected frost date in the spring under grow lights. Be sure to gradually acclimate indoor seedlings to outdoor conditions before planting them in the garden after the weather warms.

Potting and Repotting Fennel

An all-purpose, well-draining potting mix is typically fine for fennel. For container growth, aim to choose a pot that will accommodate the plant's mature size right from the start to avoid having to repot. Fennel doesn't like its roots disturbed. So that means using biodegradable pots for seedlings that can be planted directly in the soil.

Overwintering

If frost is expected in your area, go ahead and harvest the rest of your fennel plant. Otherwise the foliage will likely be damaged or killed. In mild climates, fennel plants can be overwintered for a second growing season, but they usually degrade after that. If unseasonably cold weather is expected in those climates, cover the plants with row covers or another form of protection.

Common Pests and Plant Diseases

Fennel rarely suffers from serious pest or disease problems, though caterpillars might chew on the leaves. This is best handled simply by picking them off the plants by hand. Most often, they are parsley worm caterpillars, which evolve into black swallowtail butterflies, beneficial pollinators for the garden. You can, therefore, choose to ignore these green caterpillars with black and yellow bands if they're not causing a major issue.

Aphids also can sometimes be an issue, but they can be treated by strong sprays of water to dislodge them. Avoid using chemical pesticides on edible herbs.

In soil with poor drainage, root rot can occur. If you have heavy soil, try a raised garden bed or container to achieve optimal soil conditions.

How to grow fennel: as a herb or vegetable

(Image credit: Getty Images)

Learn how to grow fennel for an all-round culinary staple that you can harvest from spring through fall. Not only do fennel's aniseed notes add a delicious, aromatic flavor to food, but the plant also has medicinal properties, in particular aiding digestion.

There are two main types of fennel – the traditional herb variety, with feathery green or bronze foliage that is harvested as needed, and the closely related bulb (Florence) fennel, which is harvested in its entirety. Both are worth including in your list of kitchen garden ideas as they will enhance so many dishes, from fish and vegetables to curries, soups and sauces. 

‘Fennel is considered both a vegetable and a herb. It is not difficult to grow and is a popular addition to organic gardens because it attracts ladybugs, which are natural predators of some of the most insidious pests,’ says Period Living's gardening expert Leigh Clapp.

‘Fennel serves a dual purpose in a kitchen garden as it adds scent and texture, and also looks lovely as an airy infill in a cut bouquet.’

(Image credit: Getty Images)

How to grow fennel as a herb

The herb fennel is a perennial plant that's best grown from seed. The seedlings do not like to be transplanted, so ideally sow directly where the plants will grow. Choose a site with plenty of sun and free-draining soil.

Do not plant fennel close to dill, as the herbs will cross-pollinate, which has a negative impact on flavor.

  1. First – when to plant fennel? ‘Sow seeds as soon as the soil can be worked early in the season,’ says Clapp. In the northern hemisphere, that is likely to be early to mid spring, in March or April. ‘Incorporate plenty of organic matter into the soil.’
  2. Create rows or drills around half an inch deep and 15in apart. Sow seeds thinly and cover with soil. 
  3. Water the soil and keep moist but do not excessively soak it. Germination should take 1-2 weeks.
  4. When the seedlings have grown large enough to handle, thin them out to around 12in apart.
  5. Succession sow every few weeks until late summer for a continual supply of fennel.
  6. Once the plants are established, fennel does not require a lot of attention – water only as needed, and particularly in hot weather, and fertilize occasionally.
  7. Remove dead stems at the end of the growing season.
  8. Though fennel is a perennial herb, it will need replacing after 3-4 years.

(Image credit: Getty Images)

How to grow fennel bulb

Fennel is one of those vegetable garden ideas that takes a little work and attention but is more than worth the effort.

Fennel bulbs – also known as Florence fennel – are not quite as easy to grow as herb fennel, but they are well worth the effort as they can be eaten raw or cooked, and are a staple of Italian cuisine. ‘Even experienced gardeners find Florence fennel a challenge,’ says gardening expert Matt James.

The issue with fennel bulbs is they they are prone to bolting, meaning the plant will flower and go to seed too quickly. To prevent fennel bulbs from bolting, choose a bolt-resistant variety, avoid sowing seed too early or transplanting the seedlings, and keep the soil moist. 

Aside from taking precautions against bolting, fennel bulbs are straightforward to grow.

  1. Sow seed directly where you want the plants to grow, in mid to late spring. 
  2. If you want to start fennel earlier indoors, then sow only one seed per small pot or module and take care to transplant the contents of each pot in its entirety, to avoid disturbing the roots.
  3. Plant seeds around half an inch deep in rows set around 15 inches apart. Sow seeds thinly and cover with soil.
  4. When the seedlings are large enough to handle, thin them out to 12 inches apart.
  5. Keep the soil moist throughout the growing season, to minimize the risk of bolting.
  6. Though not essential, you can earth up the bulbs as they grow, which will blanche them and protect them from late-season frosts.
  7. Feed the plants every two weeks with a high potash feed.
  8. You can harvest the bulbs from late summer through fall.

(Image credit: Getty Images)

Which type of fennel?

When it comes to selecting a type of fennel, you can choose from the herb or bulb variety – both share a sweet aniseed flavor.

Common fennel is widely available as a herb, but bronze fennel is well worth adding to your herb garden. As its name suggests, it has striking bronze foliage. ‘Bronze fennel is a stunning back-of-the-border favourite,’ says James.

For bulb or Florence fennel, try Perfection, Zefa Fino, Sirio, Romanesco, and Dragon.

(Image credit: Leigh Clapp)

How to grow fennel in pots

Growing fennel in pots is a great idea for a vegetable container garden. The plants' feathery leaves make a striking feature, and you can keep them close to hand on the patio.

Sow the seed directly into a container filled with free-draining potting mix.

'Fennel will need a reasonable amount of space to grow if it is to develop a decent-size bulb – I have three growing in a 12-inch pot – but if you find you have overplanted, you can always eat the thinnings too,' says Aaron Bertelsen in Grow Fruit and Vegetables in Pots .

'If you are interplanting with another crop – say, lettuces – make sure you leave enough space for the fennel to grow without being smothered. And be careful not to accidentally weed it out. Daily watering is vital too.'

(Image credit: Getty Images)

How to harvest fennel

Every part of a fennel plant is edible, from the frothy fronds to the earthy roots, which are great roasted or cooked into dishes. Fennel seeds are particularly aromatic and can be used in cooking and even infused for tea.

Fennel can be harvested within around three months of sowing. For the herb variety, simply cut off the foliage as desired.

To harvest bulb fennel, cut the bulb above the soil. If you leave the root in the ground, it may regrow for a second, smaller harvest.

To gather the seeds, you will need to leave some flowers on the plant so that seeds will start to form. You can eat them green, fresh from the plant, but they are best dried.

To dry the seeds, wait until they have turned pale brown, then hang the stems upside down to dry in a paper bag. Once the seeds are totally dry, store them in an airtight jar.

Fennel pests and problems

The biggest problem with fennel is usually bolting, although this is more of an issue with the bulb or Florence varieties. You can take steps to avoid this, including keeping the plants moist and not transplanting them. However, choosing a bolt-resistant variety is the best way to minimize risk.

When the plants are small, slugs and snails can be an issue, so protect them with barriers or biological controls.

Aphids can also cause issues – keep them at bay by making a spray with water and a weak concentration of dish soap.

How long does it take to grow fennel?

To grow fennel bulbs takes around 3 months from sowing until the plant is ready to harvest, depending on the variety.

When growing fennel as a herb, you can also begin to harvest the foliage within around 3 months from sowing.

Does fennel come back every year?

The herb fennel is a short-lived perennial, so will come back each year. However, the plants will only last 3-4 years before you need to replace them.

Fennel bulbs are harvested in their entirety for culinary use, so are grown as annuals.

Where does fennel grow best?

Fennel grows best in a sunny site with free-draining soil. It does not like too much shade, and will struggle if the soil is prone to becoming waterlogged.

Why is fennel a bad companion plant?

Fennel is considered a bad companion plant as it can have a negative impact on other herbs and vegetables.

'Though fennel is beautiful, edible and attracts pollinators, it needs to be planted separately or with ornamentals as it can inhibit the growth of vegetables,' says Clapp.

In particular, fennel should not be planted near dill, as the plants will cross-pollinate, causing them both to taste unpleasant.

As editor of Period Living, Britain's best-selling period homes magazine, Melanie loves the charm of older properties. I live in a rural village just outside the Cotswolds in England, so am lucky to be surrounded by beautiful homes and countryside, where I enjoy exploring. Having worked in the industry for almost two decades, Melanie is interested in all aspects of homes and gardens. Her previous roles include working on Real Homes and Homebuilding & Renovating, and she has also contributed to Gardening Etc. She has an English degree and has also studied interior design. Melanie frequently writes for Homes & Gardens about property restoration and gardening.

Fennel. How to cultivate a Florentine delicacy

There are several types of fennel:

Foeniculum vulgare subsp. piperitum (bitter fennel), Foeniculum vulgare subsp. vulgare var. dulce (sweet fennel) and Foeniculum vulgare subsp. vulgare var. azoricum (Florentine, vegetable fennel)

Vegetable forms of fennel differ from each other in the shape and color of the rosette of leaves, but most importantly - in the shape and size of the sprout. There are varieties with flat or round heads. Plants grow slowly during the initial period of growth. Before stemming, their height reaches 40-60 cm.
To successfully grow fennel, you must meet the requirements for heat, light, moisture, soil, nutrition.

Growing Conditions for Fennel

Fennel prefers areas with long warm and humid summers and mild winters. It grows well on fertile soils, rich in lime, of medium and heavy mechanical composition, with a pH of 6.5-8. Clay and marshy soils are unsuitable for fennel. It responds positively to the introduction of compost and fertilizers with a high organic content. With a lack of nutrients, vegetable fennel forms small heads of cabbage.

Vegetable fennel develops best with a short day and low air temperature. In the conditions of a long day and with a lack of moisture in the soil, vegetable fennel forms flower-bearing shoots in the first year of cultivation, bypassing the sprout phase at the base of the stem.

Fennel is light-requiring and does not tolerate shading well

The culture must be watered regularly, because in plants that do not receive enough water, or if watering is irregular, the stems crack and the commercial quality of the heads deteriorates.

Given the growing season, fennel cultivation requires 200-350 mm of natural rainfall or irrigation moisture, depending on the type of soil and its water supply. Dry air can also prevent the full development of sprouts. In small areas, drip irrigation is used to maintain soil moisture.
The best predecessors of fennel are row crops (under which high doses of organic fertilizers were applied) or grain crops. You can grow it after cabbage. Fennel also tolerates cultivation in monoculture.

Fennel can be grown by direct sowing of seeds into the ground or through seedlings

The growing season of vegetable fennel lasts 90-100 days. It can be grown by direct sowing of seeds into the ground or through seedlings. To grow a sufficient number of seedlings on an area of ​​1 ha, 2.5 kg of seeds are needed. For direct sowing in the same area, 8-10 kg of seeds are required.
Since autumn, the area must be plowed up or dug up to the depth of the arable layer. Before sowing in early spring, the soil is loosened or dug up beforehand.

For an average yield (20 t/ha), the above-ground mass absorbs NPK 58-26-194 kg/ha. Depending on the type of soil and the amount of nutrients in it, 80-120 kg/ha N, 70-100 kg/ha P (P2O5), 120-160 kg/ha K (K2O) are required for fertilizer. Phosphorus-potassium fertilizers are used as the main ones.

On sandy soils, nitrogen losses are more significant (40-70 kg/ha), with frequent irrigation, potassium can be leached (up to 10%).
To reduce the burden on the environment, nitrogen fertilizers can be applied in several steps. On moderately heavy soils, they can be given in one go. On neutral or slightly alkaline, ammonium nitrate is replaced with ammonium sulfate.

Sowing fennel, care and feeding

Seeds begin to germinate at 6 °C, the optimum air temperature for plant growth and development is 15-20 °C. Shoots appear in 12-14 days. In the marketable phase, plants tolerate frosts. Vegetable fennel can be sown in open ground when the danger of a strong drop in temperature (down to -2 ° C) has passed.

Care must be taken in doing so, as early crops are more likely to bloom. Fennel vegetable is sensitive not only to the length of daylight hours, but also to a sudden change in temperature. Therefore, if possible, it is better to sow by direct sowing, and not through seedlings, in order to reduce the likelihood of transition to stemming.

Seeds usually germinate in 7-10 days. To speed up germination, before sowing, they are soaked for 3 hours in warm water, then dried. To enhance germination energy and germination, seeds can be treated with growth stimulants (Zircon, Epin-extra, Epin, Albit).
In the southern regions, vegetable fennel is sown every 3-4 weeks for conveyor cultivation of heads of cabbage.

Last sowing date should be 90-110 days before the first autumn frosts

In northern latitudes, vegetable fennel is sown during the summer solstice. If sowing is carried out in mid-June, the crop is harvested in mid-October. Cabbage sprouts can survive one or two frosts, so you can harvest when cold weather sets in.

The classical sowing rate of fennel seeds is 0.5-1.2 g/m2

The sowing method is in rows with a row spacing of 60-70 cm. - mi in the tape - 20-25 cm. 5-7 days after sowing, harrowing is carried out in order to control weeds. Shoots appear in 20-25 days. When the plants reach a height of 15-20 cm, they must be thinned out.

According to foreign sources, in the southern regions, vegetable fennel can be sown by direct sowing to a depth of 0.6-1.3 cm with a row spacing of 107 cm. There are 2 lines of seeds on one bed, the distance in a row between seeds is 15 cm. With direct sowing the recommended plant density is 13 pcs/m2. A denser or weaker standing density can provoke stemming in varieties that are sensitive to day length.

According to other sources, the sowing depth of seeds should be 0. 6 cm, the distance between seeds in a row should be 10-15 or 15-30 cm, and between rows should be 46 cm.
Sometimes 3 seeds are sown together in one place, leaving 30 cm between each three seeds in a row, and then thinned out, leaving the strongest seedling.

If the soil is dry at the time of sowing, the furrows must first be well watered. After sowing, the seeds are mulched with a soil layer 0.2-1.3 cm thick. Vegetable varieties of fennel are thinned out at a distance of 15 cm between plants in a row. After this, the plants can be lightly hilled. According to data from foreign literature, at the beginning of the formation of heads of cabbage, plants are thinned out at a distance of 20-30 cm in a row from each other.

When the sprouts have reached the size of a hen's egg, it is necessary to spud up the rows, lightly powdering the soil around the sprout to bleach it.

To make the sprouts more tender and sweeter in taste, as well as to prevent the growth of weeds and maintain coolness and moisture in the upper soil layer, it is necessary to mulch the soil with straw or hay

per season) and weeding in a row. On light soils with a lack of moisture, watering is necessary.

When growing vegetable varieties, it is necessary to feed the plants 1 time during the growing season. Top dressing is carried out when 3-4 pairs of true leaves are formed: 10-12 g/m2 of ammonium nitrate, 20-25 g/m2 of superphosphate and 10-12 g/m2 of potassium salt.

Fertilizers are applied in the middle of the row spacing to a depth of 10-12 cm. To obtain more tender and bleached heads of cabbage, at the first signs of thickening of the stem, the plants are lightly spudded.

How to harvest and store fennel

Commercial sprouts of class I should weigh 250-350 g. It takes about 3 months to obtain full fennel sprouts. Heads of vegetable varieties are harvested in late autumn when they reach a diameter of 8-10 cm, when they become hard to the touch.

They are cut at the root and all leaves are removed at a height of 15-20 cm, otherwise there is a danger of wilting. For cutting, it is better to use a sharp knife or secateurs. The sprout is cut just above the tap root, right at the soil line. The leaves are cut above the head of cabbage at a height of 2.5-5 cm to prepare for sale or storage.
After harvesting, they are washed and packed 20 sprouts in 1 carton. To meet standards, at least 90% of fennel sprouts must be free from insects, worms, mold, rot and other defects that affect product quality. They can also be refrigerated and packed in plastic bags. The shelf life in them is up to 5 days, without packaging in the refrigerator - up to 1 week, or 2-3 months in a cold and humid place. The best storage conditions are 0 °C and relative humidity 95%.
The ideal marketable yield of sprouts (without stem and leaf residues) is, depending on the variety, 1.5-2.5 kg/m2.

Fresh fennel greens are rich in vitamins
(B9 - Folic acid, C - Ascorbic acid, vitamins A, pp, B5, B6, B2), macro-
and microelements. Of the macronutrients, there are potassium, sodium, phosphorus, calcium, magnesium. Of the trace elements - manganese, copper, iron, selenium, zinc.

Fennel seeds contain 0.79% essential oil, which has a strong spicy aroma and taste, 5.82% fatty oil and the total amount of phenolic compounds - 1.17 mg/g dry weight. the main components of the essential oil are anethole (50-60%) and fenchone (15-20%).
Raw fennel sprouts contain carbohydrates, dietary fiber, protein, vitamin B complex, vitamin C and minerals.

Fennel through seedlings

To obtain better and earlier yields of vegetable varieties, the seedling method of cultivation is used. For this, plants are sown in boxes or cassettes in a warm room 4-6 weeks before the start of the frost-free period.

Growing fennel through seedlings is useful in areas with a short spring or a short warm period in general (northern latitudes)

Fennel does not tolerate root disturbances. 3 seeds are sown in the cell of the cassette to a depth of 0. 6 cm. When the seeds germinate, the strongest seedling is left in the cell.

Plants are transplanted into open ground from mid-spring to the end of summer, when seedlings are 4-6 weeks old and 8-10 cm high. Row spacing 46 cm wide, between plants in a row - 15-30 cm. It is advisable not to thicken plantings. so as not to provoke the transition to stalking. With the classical planting scheme, when the seedlings reach the age of 45-60 days, they are planted in open ground when there is no threat of return frosts (end of May - beginning of June). The method of planting seedlings is 40 × 20 cm or 40 × 30 cm.

Florentine sweet fennel leaves and head are used raw and cooked. The cabbage can be fried, stewed, grilled. It is a very good source of dietary fiber, as well as calcium, potassium and fiber, and lowers blood cholesterol levels.

Fennel roots are edible. The taste is reminiscent of root parsley. They are added to vegetable stew. The leaves are crushed and added to soups and as a seasoning for fish. Stems and young umbrellas are preserved separately, added when pickling cucumbers and other vegetables. The stems are dried or frozen. Young leaves of vegetable fennel can be added to a salad for children.

Aleksey Baranov, Candidate of Biological Sciences, Gavrish Company

About growing fennel outdoors: planting, caring for, harvesting

This guide contains simple tips for growing fennel from seeds outdoors. Learn all about how to sow and grow it in the country, how to care for and harvest leaves, heads and seeds.

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