Plants feeding plants. There is something rather beautifully circular about it.

Long before garden centres sold rows of bottled fertilisers, growers were making fertility from what they had around them: nettles from the hedgerow, comfrey from the edge of the garden, seaweed from the coast, leaves from the woodland floor, and green plants grown specifically to be returned to the soil.

Plant-based fertilisers are part of a bigger way of thinking about growing. Instead of seeing fertility as something that must always be bought in a bag, they help us ask: what can the land already provide?

For gardeners, allotment growers and market gardeners looking to avoid synthetic fertilisers, plant-based feeds can be a brilliant part of an organic or regenerative system. The RHS describes organic fertilisers as being derived from living things and lists plant-based examples, including seaweed, sugar beet, digestate, comfrey and nettles.

This guide explores the most useful plant-based fertilisers, including comfrey, nettle, seaweed and botanical feeds. We will look at what they offer, how to use them, when not to use them, and how to avoid the classic “more must be better” trap. Spoiler: In gardening, more is very often where the chaos goblin lives.

What Are Plant-Based Fertilisers?

Plant-based fertilisers are feeds, soil improvers or plant tonics made from plants, algae or plant-derived materials. They may be homemade, such as nettle tea or comfrey liquid feed, or commercially produced, such as seaweed extract, sugar beet-derived fertilisers or plant-based pellets.

They are usually used to:

  • Feed crops naturally

  • Recycle nutrients

  • Reduce dependence on synthetic fertilisers

  • Support soil biology

  • Improve plant resilience

  • Make use of local resources

  • Fit organic, veganic or regenerative growing systems

Some plant-based fertilisers act mainly as nutrient feeds. Others are more like biostimulants, helping plants cope with stress or improve growth processes rather than simply supplying large amounts of nitrogen, phosphorus and potassium.

The RHS notes that organic fertilisers are usually less concentrated and slower-acting than inorganic options and that they typically have a smaller carbon footprint.

Plant-Based Fertilisers vs Synthetic Fertilisers

Synthetic fertilisers are often designed to deliver nutrients quickly and predictably. They can be useful in some systems, but they do not necessarily improve soil structure or biological life.

Plant-based fertilisers tend to work differently. They are often gentler, more complex, and more connected to the wider soil ecosystem.

FeaturePlant-Based FertilisersSynthetic FertilisersSourcePlants, algae, crop by-products, botanical extractsManufactured mineral salts or industrial productsSpeedOften slower or moderateOften fast-actingSoil biologyCan support microbial life, especially when used with organic matterMay feed plants but does not necessarily build soilNutrient precisionMore variableMore predictableSustainabilityCan be local, circular and low-wasteOften relies on industrial inputsRiskCan still be overused, but often gentlerCan leach, scorch plants or create imbalance if misused

The goal is not to be purist for the sake of it. The goal is to build soil fertility in a way that supports plants, soil life, climate resilience and long-term growing.

1. Comfrey Fertiliser

Common name: Comfrey

Latin name: Symphytum officinale and Symphytum × uplandicum

Plant family: Boraginaceae

Where It Grows

Comfrey is a robust perennial plant often found in damp grasslands, hedgerows, stream edges, old gardens and fertile soils. It has large, hairy leaves and bell-shaped flowers that are loved by bees.

In gardens and permaculture systems, the most famous comfrey variety is Bocking 14, a sterile hybrid of Russian comfrey, Symphytum × uplandicum. It is popular because it does not spread freely by seed, although it can still regrow from root fragments.

Why Gardeners Use Comfrey

Comfrey is one of the classic plant-based fertilisers because it produces a huge amount of leafy growth that can be cut several times a year. Garden Organic describes comfrey as easy to grow and harvest, producing leaves rich in nitrogen, phosphorus and potassium.

It is especially valued as a feed for fruiting crops, including:

  • Tomatoes

  • Peppers

  • Cucumbers

  • Courgettes

  • Squash

  • Beans

  • Fruit bushes

  • Fruit trees

Comfrey is often described as a potassium-rich feed, which is why it is so closely associated with flowering and fruiting plants.

What Comfrey Offers

Comfrey can provide:

  • Potassium for flowers and fruit

  • Nitrogen for leafy growth

  • Phosphorus in smaller amounts

  • Trace minerals

  • Organic matter

  • Mulch material

  • Compost activator material

  • Bee-friendly flowers

Research and practical trials suggest comfrey can be a useful plant nutrient source. An older report on Symphytum × uplandicum found comfrey liquid to be a rich source of potassium, although it noted that additional organic nitrogen may be needed for a more balanced fertiliser.

How to Make Comfrey Liquid Feed

The simple method:

  • Harvest comfrey leaves before or during flowering.

  • Chop the leaves roughly.

  • Pack them into a bucket or barrel.

  • Weigh them down with a stone or brick.

  • Add water, or make a concentrated no-water feed by letting the leaves break down.

  • Leave for several weeks.

  • Strain and dilute before use.

The water method makes a brown liquid feed. The no-water method makes a darker, thicker concentrate that needs heavier dilution.

How to Use Comfrey Feed

Use diluted comfrey feed:

  • Around tomatoes once flowering begins

  • Around courgettes and squash

  • For container-grown fruiting crops

  • Around hungry flowering plants

  • On fruit bushes in the growing season

A common dilution is around 1 part comfrey liquid to 10 parts water, though homemade feeds vary, so it is sensible to start weaker.

Other Ways to Use Comfrey

Comfrey is not just for liquid feed. You can also use it as:

  • Chop-and-drop mulch

  • Compost heap activator

  • Mulch around fruit trees

  • Leaf layer in potato trenches

  • Green material in compost systems

Benefits of Comfrey Fertiliser

  • Easy to grow once established

  • Produces lots of biomass

  • Excellent for circular fertility

  • Can be grown on-site

  • Popular with pollinators

  • Useful for fruiting crops

  • Reduces need for bought fertiliser

Negatives and Cautions

Comfrey is powerful, but not perfect.

Possible drawbacks include:

  • Can spread from root fragments

  • Homemade feed smells very strong

  • Can be too rich if overused

  • Not a complete fertiliser on its own

  • Large leaves can smother small plants if used badly as mulch

  • Some species can self-seed freely

Also, comfrey has medicinal associations but should not be treated casually as an edible or internal herbal remedy. For this article, we are talking about using comfrey as a plant feed, not a human medicine.

2. Nettle Fertiliser

Common name: Stinging nettle

Latin name: Urtica dioica

Plant family: Urticaceae

Where It Grows

Stinging nettle grows widely across the UK and Europe. It loves nitrogen-rich soils and is often found in hedgerows, woodland edges, field margins, old farmyards, compost areas and disturbed ground.

If nettles are growing strongly, they are often telling you something: the soil is fertile, rich in nitrogen and probably full of organic matter.

Why Gardeners Use Nettles

Nettles make a classic homemade liquid feed. The RHS says homemade fertilisers can be made using garden plants, weeds or other organic matter, and lists nettles among useful ingredients.

Nettle feed is often used earlier in the season because it is associated with leafy growth.

What Nettles Offer

Nettle fertiliser can provide:

  • Nitrogen

  • Potassium

  • Iron

  • Magnesium

  • Trace minerals

  • Plant compounds

  • A useful liquid feed for leafy crops

A Garden Organic report comparing comfrey and nettle liquid feeds found that nettle feeds had more nitrogen than comfrey feeds, while both nettle and comfrey produced high-potash liquids suitable for feeding tomatoes.

That is a useful finding because it challenges the neat little gardening cliché that “nettles are only nitrogen” and “comfrey is only potassium.” Nature, as usual, refuses to fit into our tidy boxes.

How to Make Nettle Liquid Feed

  • Harvest young nettles before they set seed.

  • Wear gloves because nettles are spicy little beasts.

  • Chop the stems and leaves.

  • Place them in a bucket.

  • Cover with water.

  • Weigh them down.

  • Leave for 2–4 weeks.

  • Strain and dilute before use.

How to Use Nettle Feed

Use nettle feed:

  • On leafy crops

  • On brassicas

  • On young plants during vegetative growth

  • On container plants needing a boost

  • On compost heaps as a nitrogen-rich activator

Dilute before applying. A typical starting point is 1 part nettle feed to 10 parts water.

Best Crops for Nettle Feed

Nettle feed is useful for:

  • Kale

  • Cabbage

  • Chard

  • Spinach

  • Lettuce

  • Leeks

  • Courgettes in early growth

  • Young tomatoes before flowering

  • Hungry container plants

Benefits of Nettle Fertiliser

  • Free and widely available

  • Fast-growing and easy to harvest

  • Good way to recycle weeds

  • Useful nitrogen-rich feed

  • Supports low-cost gardening

  • Excellent for allotments

  • Can reduce reliance on bought liquid feeds

Negatives and Cautions

Nettle feed has a few downsides:

  • It smells dreadful when fermented anaerobically

  • It can be too strong if undiluted

  • Nettles should be harvested before seed set

  • Avoid collecting from polluted roadsides

  • Wear gloves when harvesting

  • Do not splash strong feed on tender leaves

Also remember that nettles are important wildlife plants, especially for butterflies such as small tortoiseshell, peacock and comma. Harvest from abundant patches and leave some for nature.

3. Seaweed Fertiliser

Common names: Seaweed, kelp, wrack, sea lettuce

Latin names: Common examples include:

  • Bladderwrack - Fucus vesiculosus

  • Knotted wrack - Ascophyllum nodosum

  • Serrated wrack - Fucus serratus

  • Kelp - Laminaria spp.

  • Sea lettuce - Ulva lactuca

Where It Grows

Seaweed grows in marine environments, from rocky shores and tidal pools to deeper coastal waters. Different species occupy different tidal zones. Brown seaweeds such as wracks and kelps are especially common in cooler North Atlantic waters.

Coastal communities have used seaweed for centuries as a soil improver and fertiliser. It was spread on fields, added to potato plots, composted, or used as mulch.

Why Gardeners Use Seaweed

Seaweed products are popular with organic growers, especially those looking to avoid synthetic fertilisers or animal-based feeds. The RHS says seaweed products are useful for organic gardeners wanting to avoid synthetic fertilisers or fertilisers made from animal products, and notes that seaweed provides potassium, magnesium and trace elements.

What Seaweed Offers

Seaweed can provide:

  • Potassium

  • Magnesium

  • Trace elements

  • Organic matter

  • Natural plant compounds

  • Support for stress tolerance

  • Biostimulant effects

  • Improved plant vigour

Modern research often discusses seaweed extracts as biostimulants. A 2024 review describes seaweed extracts as containing compounds that support plant growth and stress mitigation in horticultural crops. Another 2024 review explains that seaweed extracts are being studied for their ability to improve plant tolerance to biotic and abiotic stresses.

Seaweed as a Fertiliser vs Seaweed as a Biostimulant

This distinction matters.

A fertiliser provides nutrients. A biostimulant supports plant processes.

Seaweed may do both, but many seaweed products are not mainly used because they contain huge amounts of NPK. They are often valued for trace elements and bioactive compounds that may help plants cope with stress, establish roots or improve resilience.

How to Use Seaweed

Seaweed can be used as:

  • Liquid seaweed feed

  • Foliar spray

  • Soil drench

  • Compost ingredient

  • Winter mulch

  • Transplant tonic

  • Seedling support, depending on product instructions

Commercial seaweed feeds are usually the most reliable option because they come with dilution rates and are processed for garden use.

Using Fresh Seaweed

Fresh seaweed can be useful, but there are important cautions:

  • Check local collection rules

  • Do not harvest from protected areas

  • Do not strip living seaweed from rocks

  • Collect loose seaweed only where permitted

  • Rinse or weather it if salt levels are a concern

  • Compost it or use it as a winter mulch

Seaweed is habitat, not just free fertiliser. Tiny creatures live in it, birds feed around it, and coastal ecosystems depend on it. So yes, seaweed is wonderful - but don’t be that person carting off half the beach like a Victorian kelp baron.

Benefits of Seaweed Fertiliser

  • Useful source of trace minerals

  • Good for organic systems

  • Often suitable for vegan growers

  • Can support plant resilience

  • Useful as a foliar feed or a soil drench

  • Long history of coastal agricultural use

  • Can complement compost and green manures

Negatives and Cautions

Potential downsides include:

  • Salt content in fresh seaweed

  • Unsustainable harvesting

  • Variable nutrient levels

  • Commercial products can be expensive

  • Not a full replacement for compost

  • Overuse can encourage soft growth

  • Quality varies between products

A 2025 review of seaweed-derived biostimulants notes that seaweed biostimulants can enhance growth, stress tolerance and soil health through bioactive compounds, while also highlighting the importance of extraction methods, scalability and integration with other approaches.

4. Sugar Beet-Derived Fertilisers

Common name: Sugar beet

Latin name: Beta vulgaris

Plant family: Amaranthaceae

Where It Grows

Sugar beet is grown as an agricultural crop in temperate regions, including parts of the UK and Europe. It is cultivated for its sugar-rich root.

Why It Is Used in Plant-Based Fertilisers

Some commercial organic fertilisers use by-products from sugar beet processing. These materials can be turned into liquid or granular feeds and are often used as vegan or plant-based alternatives to animal-derived fertilisers.

The RHS includes sugar beet among plant-based organic fertiliser sources.

What Sugar Beet-Based Feeds Offer

Depending on the product, sugar beet-derived feeds may provide:

  • Potassium

  • Organic compounds

  • Plant-based nutrient sources

  • Vegan-friendly fertility

  • A use for agricultural by-products

Best Uses

Sugar beet-based fertilisers are usually best used according to product instructions, especially for:

  • Vegetables

  • Containers

  • Greenhouse crops

  • Fruit plants

  • Vegan organic growing

  • General garden feeding

Negatives and Cautions

The main issue is that “sugar beet fertiliser” is not one single thing. Products vary. Always check the label for NPK ratio, ingredients and organic certification status if that matters to you.

5. Plant-Based Digestate

What Is Digestate?

Digestate is the material left after anaerobic digestion, a process where organic matter is broken down by microbes without oxygen. Digestate can come from food waste, crops, manures or mixed feedstocks.

Plant-based digestate refers to digestate made from plant materials rather than animal manures, although in practice some digestate products may come from mixed sources.

The RHS lists digestate among plant-based organic fertiliser examples.

What Digestate Offers

Depending on source and processing, digestate can provide:

  • Nitrogen

  • Potassium

  • Organic matter

  • Recycled nutrients

  • A circular use for waste streams

Best Uses

Digestate-based fertilisers may be useful for:

  • General feeding

  • Vegetable production

  • Field-scale systems

  • Organic or low-input systems, depending on certification and source

  • Circular nutrient systems

Negatives and Cautions

Digestate quality depends heavily on feedstock and processing. For organic growers, certification and source transparency matter. For gardeners, commercial labelled products are much easier to use safely than raw digestate from unknown sources.

  1. Botanical Feeds and Plant Teas

Botanical feeds are homemade or commercial plant-based extracts used to feed plants or support plant health. They may be fermented, steeped, brewed or extracted.

Common botanical feeds include:

  • Comfrey tea

  • Nettle tea

  • Horsetail tea

  • Dandelion tea

  • Willow water

  • Yarrow tea

  • Seaweed extract

  • Alfalfa tea

  • Moringa leaf extract

  • Fermented plant juice

7. Horsetail Tea

Common name: Field horsetail

Latin name: Equisetum arvense

Horsetail is rich in silica and has a long history of use in biodynamic and organic gardening circles. It is often used as a plant-strengthening spray, particularly where fungal disease pressure is a concern.

Caution: horsetail can be highly invasive, so grow or harvest it carefully.

8. Dandelion Feed

Common name: Dandelion

Latin name: Taraxacum officinale

Dandelions have deep taproots and accumulate minerals from the soil. They can be added to plant teas or compost. They are also valuable early flowers for pollinators, so avoid stripping them all out of the garden.

9. Willow Water

Common name: Willow

Latin name: Salix spp.

Willow has long been used in homemade rooting preparations. Young willow stems contain compounds associated with rooting and plant defence responses. It is usually used for cuttings rather than as a general fertiliser.

10. Alfalfa Feed

Common name: Lucerne / alfalfa

Latin name: Medicago sativa

Alfalfa is a legume used as forage and green manure. Alfalfa meal and pellets are used in some organic gardening systems as a plant-based nitrogen source.

11. Moringa Leaf Extract

Common name: Moringa

Latin name: Moringa oleifera

Moringa leaf extract is often discussed as a natural plant biostimulant in warmer climates. For UK growers, it is less local and may make more sense as a research topic than a practical homegrown fertiliser.

How to Make a Basic Botanical Liquid Feed

This method works for nettles, comfrey, dandelions and mixed green plant material.

You will need:

  • A bucket with a lid

  • Fresh plant material

  • Rainwater if possible

  • A stone or brick

  • Gloves

  • A stick for stirring

  • A sieve or a cloth for straining

Method:

  • Gather healthy plant material.

  • Avoid diseased plants or seeded weeds.

  • Chop roughly.

  • Fill the bucket about halfway.

  • Cover with water.

  • Weigh the plant material down.

  • Put the lid on loosely.

  • Leave for 2–4 weeks.

  • Stir occasionally.

  • Strain and dilute before use.

Dilution:

A sensible starting dilution is:

1 part liquid feed to 10 parts water

For tender plants, use it weaker. For established hungry crops, you can gradually increase strength if plants respond well.

How to Use Plant-Based Liquid Feeds

Use plant feeds as a supplement, not the whole fertility plan.

They work best when combined with:

  • Compost

  • Mulch

  • Healthy soil structure

  • Crop rotation

  • Green manures

  • Living roots

  • Good watering

  • Minimal soil disturbance

Apply plant-based liquid feeds:

  • To damp soil

  • In the growing season

  • Around the root zone

  • Little and often

  • More for hungry crops

  • Less for stressed or dormant plants

Avoid feeding drought-stressed plants heavily. Water first, let them recover, then feed gently.

Which Plant Feed Should You Use?

NeedBest Plant-Based FeedLeafy growthNettle feed, alfalfa feedFlowers and fruitComfrey feed, seaweed feedTrace mineralsSeaweedPlant stress supportSeaweed extract, botanical tonicsRooting cuttingsWillow waterCompost activationNettle, comfrey, alfalfaVegan organic feedingSeaweed, comfrey, nettle, sugar beet feedsLow-cost allotment fertilityNettle and comfreyMarket garden transplant supportSeaweed extract, compost extract, comfrey feedHomemade circular fertilityComfrey, nettle, dandelion, green manures

Benefits of Plant-Based Fertilisers

Plant-based fertilisers can offer many benefits for organic and regenerative growers.

1. They Reduce Reliance on Synthetic Inputs

Homemade comfrey and nettle feeds can reduce the need to buy liquid fertilisers. For allotment growers and small-scale growers, this can save money and make the growing system more self-reliant.

2. They Recycle Local Nutrients

A patch of comfrey, a nettle bed or a green manure crop can capture nutrients and biomass, then return them to the growing system.

3. They Support Soil Health

When used alongside compost and mulch, plant-based feeds contribute to a living soil approach. They are not just about NPK; they are about nutrient cycling, organic matter and biological activity.

4. They Suit Organic and Regenerative Systems

Plant-based fertilisers fit well with no-dig gardening, permaculture, organic horticulture, agroecology and regenerative farming.

5. They Can Be Vegan-Friendly

Seaweed, comfrey, nettles, sugar beet feeds and plant-based digestate can provide alternatives to animal-derived fertilisers such as blood, fish and bone, bone meal and poultry manure.

6. They Encourage Observation

This might sound soft, but it matters. Making your own feeds helps you notice the land: what grows where, which plants accumulate biomass, when crops need support, and how soil changes through the season.

That kind of observation is the heart of good growing.

Negatives and Limitations

Plant-based fertilisers are useful, but they are not flawless.

1. Nutrient Levels Vary

Homemade feeds are not standardised. One bucket of nettle tea may be stronger than another depending on plant age, water volume, temperature and fermentation time.

2. They Can Smell Terrible

Comfrey and nettle feeds can smell unbelievably bad. This is normal, but it does make them less appealing in small gardens or near neighbours.

3. They Are Not Complete Soil Care

Liquid feeds do not replace compost, mulch, cover crops or good soil structure. Feeding plants without building soil is like constantly drinking coffee instead of eating meals. Relatable, perhaps, but not ideal.

4. They Can Be Overused

Too much feed can create soft, lush growth that attracts pests or reduces flowering and fruiting. The RHS notes that too much fertiliser can cause excessive growth at the expense of flowers or fruit.

5. Some Plants Can Become Weeds

Comfrey, nettles, horsetail and dandelions all need thoughtful management. Grow useful plants, but do not create a future weeding saga for yourself.

6. Ethical Harvesting Matters

Seaweed should be collected responsibly and legally. Wild plants should be harvested from abundant, clean areas, leaving plenty for wildlife.

How to Avoid Overfeeding

Overfeeding is one of the easiest mistakes to make, especially when you have lovingly brewed a bucket of homemade plant juice and want to feel like a garden wizard.

Use these rules:

  • Start weak

  • Feed only during active growth

  • Do not feed dry, stressed plants

  • Avoid feeding late in the season when soft growth may be damaged by frost

  • Match the feed to the crop stage

  • Use nitrogen-rich feeds early

  • Use potassium-rich feeds during flowering and fruiting

  • Keep feeding records

  • Watch the plant response

  • Stop if growth becomes too soft or leafy

Signs of overfeeding can include:

  • Lots of leaves but few flowers

  • Soft, sappy growth

  • Increased aphid problems

  • Leaf scorch

  • Weak stems

  • Poor fruiting

  • Excessive green growth late in the season

Plant-Based Fertilisers for Different Growers

For Gardeners

Best options:

  • Liquid seaweed

  • Comfrey feed

  • Nettle feed

  • Leaf mould

  • Compost

  • Dandelion tea

  • Willow water for cuttings

Focus on simplicity. A comfrey patch, a nettle bucket and a bottle of seaweed extract will cover many needs.

For Allotment Growers

Best options:

  • Comfrey beds

  • Nettle feed

  • Green manures

  • Homemade plant teas

  • Seaweed meal or liquid seaweed

  • Compost crops

Allotments are perfect for closed-loop fertility. You can grow feed plants in corners, use weeds before they seed, and return nutrients to your beds.

For Market Gardeners

Best options:

  • Seaweed extract for transplants

  • Comfrey feed for fruiting crops

  • Green manures between rotations

  • Plant-based commercial feeds

  • Compost extracts

  • Alfalfa meal

  • Sugar beet-derived fertilisers

Market gardens need consistency, so homemade feeds can be useful, but commercial organic plant-based products may be more predictable for crop planning.

A Simple Seasonal Feeding Plan

Spring

Use:

  • Nettle feed for leafy growth

  • Seaweed extract for transplants

  • Compost as a base soil amendment

  • Green manures cut before planting

  • Alfalfa or plant-based pellets where needed

Best for:

  • Brassicas

  • Leafy greens

  • Young tomatoes

  • Seedlings after establishment

  • Perennials waking up

Summer

Use:

  • Comfrey feed for fruiting crops

  • Seaweed feed during stress periods

  • Nettle feed only where leafy growth is wanted

  • Botanical feeds little and often

Best for:

  • Tomatoes

  • Cucumbers

  • Courgettes

  • Beans

  • Squash

  • Peppers

  • Fruit bushes

Autumn

Use:

  • Green manures

  • Compost

  • Leaf mould

  • Chop-and-drop plant material

  • Comfrey leaves as mulch

Best for:

  • Soil cover

  • Building organic matter

  • Feeding soil organisms

  • Preparing beds for next year

inter

Use:

  • Mulches rather than liquid feeds

  • Leaf mould

  • Compost heaps

  • Seaweed as winter mulch where appropriate and legal

  • Planning rather than active feeding

Plants are mostly not asking for a smoothie in December. Let the soil rest.

Plant-Based Fertilisers and Regenerative Growing

Plant-based fertilisers are most powerful when they are part of a regenerative system.

That means:

  • Keeping soil covered

  • Reducing digging

  • Growing cover crops

  • Increasing plant diversity

  • Composting organic waste

  • Feeding soil organisms

  • Reducing external inputs

  • Using local resources

  • Observing plant health

  • Building fertility year after year

A bottle of seaweed feed is useful. A comfrey patch is useful. A bucket of nettle tea is useful.

But the real transformation happens when they sit within a living system: compost, mulch, roots, worms, fungi, bacteria, water, minerals, and thoughtful human care.

Frequently Asked Questions

What is the best plant-based fertiliser?

There is no single best plant-based fertiliser. For leafy growth, nettle feed is useful. For fruiting crops, comfrey and seaweed are excellent. For trace minerals and plant resilience, seaweed is a strong choice. For long-term soil health, compost and green manures are essential.

Is comfrey fertiliser good for tomatoes?

Yes. Comfrey feed is widely used for tomatoes because it is associated with potassium, which supports flowering and fruiting. Trials comparing comfrey and nettle feeds found both could produce high-potash liquids suitable for feeding tomatoes.

Is nettle fertiliser high in nitrogen?

Nettle feed is commonly used as a nitrogen-rich liquid feed. Garden Organic’s comparison found nettle feeds had more nitrogen than comfrey feeds.

Is seaweed a fertiliser or a biostimulant?

It can be both. Seaweed products can provide nutrients such as potassium, magnesium and trace elements, while seaweed extracts are also studied as biostimulants that may support growth and stress tolerance.

Can I use plant-based fertilisers in a vegan garden?

Yes. Seaweed, comfrey, nettles, sugar beet-derived feeds, plant-based digestate and green manures can all be used in vegan or vegan-organic systems, depending on sourcing and production methods.

How often should I use homemade plant feed?

During active growth, many gardeners use diluted homemade plant feed every one to two weeks for hungry crops. Start weak and observe plant response.

Can homemade fertiliser harm plants?

Yes, if it is too strong, used too often, applied to stressed plants, or made from unsuitable material. Always dilute homemade feeds and avoid using smelly anaerobic brews on edible leaves close to harvest.

Do plant-based fertilisers replace compost?

No. Liquid plant feeds are supplements. Compost, mulch, green manures and organic matter are still the foundation of soil health.

Plant-Based Fertilisers

Plant-based fertilisers are practical, affordable and deeply satisfying. They allow gardeners, allotment growers and market gardeners to make fertility from living plants, local resources and seasonal abundance.

Comfrey can feed fruiting crops. Nettles can support leafy growth. Seaweed can bring trace minerals and biostimulant effects. Botanical feeds can recycle weeds and wild plants back into the soil. Sugar beet and plant-based digestate can offer commercial vegan-friendly options.

Used wisely, these feeds are not just substitutes for synthetic fertilisers. They are part of a more regenerative relationship with the land.

Grow the fertility. Feed the soil. Watch the plants. Adjust gently.

That is where good natural growing begins.