Fat hen, also known as fat hen weed or yellow rocket, is a common green plant found in most gardens. It grows quickly and can take over an area of your garden if you do not keep it trimmed back.

If you find this weed in your garden, you should remove it before it takes over any more space than what it already occupies because once fat hen establishes itself, there’s no getting rid of it without digging up the entire patch.

This blog post will provide an in-depth guide on what Fat Hen are, how they grow, and how to eradicate them from your garden.

Quick Facts

Common names: Lamb, Lambs Quarters, White Goosefoot, Goosefoot, Wild Spinach, Pigweed, Dirty Dick
Scientific name: Chenopodium album L.
Family: Amaranthaceae
Origin: native
Flowering season: July to October
Habitat: fields, gardens, verges, hedgerows, farmland, waste ground, recently disturbed ground, roadsides, gravel paths, around cultivated land and gardens

Fat Hen Identification

Fat-hen is a native summer annual that can be found on both cultivated and uncultivated terrain. It can be found all over the UK but is more common in the north and west.

Fat-hen has never been seen above 1,250 feet. It thrives on sandy loams and clay but is less common in calcareous soils and gravel. It thrives in fertile soils, and manuring helps it grow more frequently.

One of the most bothersome annual weeds is fat-hen. It’s abundant in potatoes, sugar beets, and other root crops, but not so much in grains. It occurs more frequently in spring-planted crops than in autumn-planted ones.

Fat hen is an upright plant with matt green, diamond-shaped leaves and spikes of small, white flowers. The whole plant tends to be covered in a white, mealy substance.

Fat Hen (Chenopodium album), a member of the Goosefoot Family (Chenopodiaceae), is a common weed in crops, lawns and gardens. It readily adapts to disturbed habitats, where it persists from year to year through seeds that germinate when soil temperatures are at least 65°F (18°C).

Seeds can remain dormant for many years or more until the proper environmental conditions trigger them to germinate.

What does Fat Hen look like?

Characteristics that make up the Fat Hen leaf, stem, root and flower are detailed below.

The leaves of the Fat hen weed with its waxy surface
The leaves of the Fat hen weed with its waxy surface

Leaves: Oval to triangular in shape, with toothed edges that are slightly wavy. The leaves have a silvery sheen or bloom that is made up of small, wax-like crystals that repel water and are blue-green on top and sometimes with a hint of red flushing underneath.

On the ascending flower stem, the leaves become thinner and more angular.

Fat hen has long leaves with a pointy end that is about 4 inches wide at the base

Stems: Fat Hen weeds in gardens may reach 15 inches (38 cm) high with hollowed stalks carrying bright yellow flowers enclosed in papery bracts (“petals”).

Roots: The roots of the fat hen are thick, hairless and bright yellow-green. They are slightly paler at the tips and have a long white root collar.

Flowers: Between June and October, spirals of white/green small flowers on spikes coming from the leaf base and stem junction appear.

The flowers of this plant are small and they grow close to each other on thin stems that have tiny hairs growing on them.

Fat Hens produce numerous yellowish flowers that are hermaphrodite (having both male and female organs) above slender pedicels which are usually branched near their upper ends, these produce seeds that have tufts of pale hair at each end.

Balls of seeds growing along the stems of the Fat hen weeds
Balls of seeds growing along the stems of the Fat hen weeds

Seeds: Seeds are abundant, although they do not ripen until late in the season. There are many estimations for seed numbers per plant, ranging from 10 to 164,691. Seeds mature at the end of the growing season. Plants that sprout in April may produce seed rain from August to November.

Fat-hen produces multiple different varieties of seed. The majority of the seed is black and has a rough or smooth surface. A far smaller proportion of seeds, up to 5%, are big and brown, with thinner, usually smooth seed coats.

The brown seeds germinate more quickly, while the black seeds last longer in the soil. If conditions are favourable, damage to the seed coat of the black seeds will increase germination.

Brown seed plants yield the same amounts of black and brown seed as black seed plants. Immature seeds can germinate, and due to a thinner seed coat, they may germinate more quickly than ripe seeds.

Smell: This plant can be identified by its smell which resembles garlic or onions when crushed.

The Problem

Fat hen is a weed that can grow very quickly around the open ground and competes with other weeds for nutrients. It can cause issues for machinery in cropped areas and out-compete re-seeded areas of grass. 

Fat Hen Seasonal Changes

Fat-hen reacts to the environment in a very dynamic way. Plants that emerge early in the year are larger and leafier than those that sprout later in the year. A fat-hen plant is small and feeble in poor soils, yet tall and robust in rich soils.

Fat hen (Chenopodium album) seed heads developing in early sping
Fat hen (Chenopodium album) seed heads developing in early spring

Fat Hen in Spring

In early spring, before the leaves of mature plants appear, Fat Hen weed seeds can be found in a sticky yellow-green foam on wildflower heads. Seedlings soon develop into reddish-brown annuals with many small stems and distinctive heart-shaped leaves.

Larger plants are prickly from the multitude of black bristles covering their stems and leaf undersides.

They look like little, round balls on top of long stems and have an interesting patterned texture to them which resembles an ominous skull shape.

Fat Hen in Summer

By midsummer, Fat Hen weeds in gardens may reach 15 inches (38 cm) high with hollowed stalks carrying bright yellow flowers enclosed in papery bracts (“petals”). The flowers give rise eventually to seeds that drift away on the wind.

Fat hen weeds are greenish-brown in the summer, but their texture is similar to that of grass.

Fat Hen in Autumn

The leaves of fat hen weeds are bright green in the spring and summer, but turn yellow or orange as autumn approaches.

The way that fat hen weed colours change from light to dark occurs during fall months like October.

Fat Hen in Winter

Fat hen weeds are found in the winter and have a variety of colours from green to yellow. They grow up to three feet tall, can be perennial or annuals depending on location. The flowers they produce range between white and light yellows that attract bees!

Frost kills fat-hen, and seedlings that emerge in the autumn rarely make it through the winter. Seedlings that emerge early in the year may be harmed by late-spring frosts.

A clump of Fat hen found on a verge of land
A clump of Fat hen found on a verge of land

How to get rid of Fat Hen

Fat Hen is an invasive weed that has a long history of wreaking havoc on the environment. With its ability to grow quickly and produce berries, it can be difficult for farmers to get rid of this pest plant without using herbicides or other chemicals.

Thankfully there are some options available if you want help getting rid of your own fat hen infestation.

Method One – Herbicide Treatment

The best way to get rid of these weeds is by using any kind of herbicide or chemical treatment because it will kill off its roots quickly without any harm done whatsoever to other plants nearby.

Those marketed as “fast-acting” contact weed killers – killing or damaging the plant tissue they are sprayed onto or make contact with. These tend to be based on “naturally-occurring” active ingredients, such as acetic acid and natural fatty acids.

Systemic weed killers also kill the roots can also be used.

First, make sure that the sprayer has been cleaned and filled with water for proper spraying technique.

Spray the leaves when the plants are actively growing; this is mainly from March/April to September/October. Use a fine spray to thoroughly coat the leaves in small droplets.

After applying a few drops in the right spots on your target weed or area you want to be cleared out, wait 10-15 minutes before proceeding to step two which will be covering over any small plants close by until they are gone too so as not to cause harm from overspray residue left behind when using this method without doing anything else afterwards such as tilling up soil where there was once tall grasses growing patches thick enough cover an entire lawn’s worth of space.

During the summer, spray in the evening to prevent the spray from evaporating and to give maximum time for the spray to work. In spring or if overnight dew is forecast, spray earlier in the day to allow the spray to dry before dew falls.

Use weedkillers safely. Always read the label and product information before use.

Method Two – Digging it out

When trying to remove a weed in your garden, you might think that the best way is just pulling on them until they come up. However, this will only harm and kill its roots which will result in more popping back up after some time has passed.

Carefully dig out the weed, using tools like shovels and spade forks, making sure that you do not pull any roots or leaves from other plants with it. Then, take your fingers and gently unfold the root system so as not to break them before pulling it all up together into one bundle for disposal.

Method Three – Weed Burning

Burning them will kill the roots and leave nothing but ash. It’s an environmentally friendly, economical alternative for those who don’t want to buy toxic chemicals or expensive tools.

The first step to getting rid of fat hen weeds is burning them. Of course, you will need a way to start the fire for sure and some protective gear like gloves or long sleeves because it can get hot! It may take more than one burn session if they are very large plants.

You should also be cautious when using this method as these fires spread quickly so make sure that there isn’t any dry foliage nearby just in case anything goes wrong.

Seedlings with 2-6 leaves are killed by flame weeding. Fat-hen seed is susceptible to soil solarisation and can be killed by direct heating of soil. 

This is a good way to safely remove unwanted yellow plants from around select areas without causing damage or harm to other more desirable foliage and flowers nearby, which can happen when pulling out larger plants with their roots intact.

Infestation of Fat hen across an open area of land
Infestation of Fat hen across an open area of land

Management of Fat Hen

Allowing fat hen to become entrenched, as with most weeds, is a bad idea, as is allowing it to blossom and generate seeds. It will be more difficult and time-consuming to fully control as a result of this. To prevent it from taking over the garden, early detection and removal are critical.

Fat Hen travels easily on clothing, farm equipment and even shoes of passers-by, so it is sometimes difficult to control once established.

The quickest and easiest technique of control is to hoe seedlings and young plants as soon as you see them. Hoeing is used to sever weed stems at or near ground level, separating the top growth from its roots.

A sharp hoe blade will make this process even faster and easier, so sharpen your hoe blade before using it. Plants will quickly dry and perish if hoeing is done on a hot and/or windy day.

Covering bare soil with a weed-control membrane (landscape cloth) or even thick black plastic will keep seeds from sprouting by blocking light.

Mulching the soil with organic debris, such as bark mulch, will also help. Mulches must be at least 5cm (2in) thick to function correctly, but 7.5cm (3in) deep is preferable.

Though it is time-consuming, hand weeding or hoeing beds and borders can be the best way to control this weed. However, there are a number of specialist herbicides available that will control Fat Hen. 

In Conclusion

Though it is time-consuming, hand weeding or hoeing beds and borders can be the best way to control this weed. However, there are a number of specialist herbicides available that will control Fat Hen.

Hopefully, in this article, you’ll have several ways to remove this pesky weed from your property and use your space more productively.

How does Fat Hen spread?

Through seedlings only.