Featured in
The Daily Telegraph
A feature on the fertiliser behind Wimbledon's grass courts named polyhalite as part of the All England Club's turf programme, and named Dr Forest as the only UK retailer selling it direct to gardeners.
About
About Dr Forest
It started with seaweed on a Welsh beach.
I'm Joe. I formulate and hand-blend every Dr Forest organic fertiliser myself, in a small unit in Stockport. British-sourced where possible, no fillers, and every claim backed by the science on the product page.
As featured in The Daily Telegraph and recommended by Alys Fowler in The Guardian.
Hand-blended in StockportMade with organic ingredients
2020
Founded
70+
Blends & amendments
4.89/5
Average across 3,250+ verified reviews
One
Pair of hands behind every bag
The Science
NPK is the easy part. The cation balance underneath is what makes a blend.
Here is the idea in plain terms. Plants take up calcium, magnesium and potassium in competition with one another, so the balance between those three matters as much as the headline NPK on the front of the bag. Get the balance right and the plant builds quality, not just bulk. Most shop-bought feeds never look at it. It is the balance every Dr Forest blend is built around.
A lot of gardening advice is built on ideas that were disproved years ago and still get followed anyway. Roses are the easy example. High-phosphorus rose feeds are still sold and widely recommended, mostly on tradition. When I went through the literature myself, I found two peer-reviewed trials where the best yield came from the lowest phosphorus level they tested. Roses respond far more to a good calcium and potassium balance than to extra phosphorus, and our Rose & Flower 5-3-5 is built around that.
So before I make any blend, I read the trial data on what the plant actually needs, then work back to the ingredients. Every Dr Forest organic fertiliser starts from a target balance of calcium, magnesium and potassium. The NPK on the front of the bag is the last number to land, not the first.
Most of our crop blends sit around a 3:1:3 balance of calcium to magnesium to potassium, the figure that comes up most often in the research on fruit quality.
Target cation ratio
3 : 1 : 3 · calcium, magnesium, potassium
Ca · Calcium
Mg
K · Potassium
The balance we work back to for most of our crop-specific blends. NPK lands after this.
Potassium and magnesium compete at the root, and the competition is one-sided. Push in plenty of potassium without enough magnesium and the potassium wins, so the plant shows magnesium deficiency even with magnesium sitting in the soil. It is the most common cause of magnesium deficiency in the field, and almost no shop-bought feed accounts for it. Field trials put the ratio where both are reliably taken up at about three parts potassium to one part magnesium, which is exactly how our blends are built. The reverse, magnesium crowding out potassium, is far weaker and not the practical worry it is often made out to be.
There is also an old idea that your soil has to hit one perfect calcium-to-magnesium-to-potassium ratio. It has been tested for decades and doesn't hold up, so we don't chase it. We balance the feed for plant quality, not the soil to a magic number. What's on the bag is what's in the bag, and the maths is on every product page.
How We Research & Write
How the guides and articles on this site get made.
Everything I publish here, the growing guides, the blog posts, the science notes on each product page, starts in the same place as the fertiliser, with the research. I read the trial data first, then write.
The expertise, the formulations and the final call are mine. I use AI to help draft and structure, so I get from my notes and the source papers to a working draft faster, then I do the part that counts. Every figure is checked against the original paper, anything that doesn't hold up is corrected, and the whole thing is rewritten in my own words before it goes live. If a claim can't be stood up against a credible source, it doesn't get published.
Every claim on the site is checked against its source before it goes live. By me.
If you ever spot something that looks wrong, email me and I'll put it right. My address is at the bottom of this page.
Inside The Unit
Every Dr Forest fertiliser is hand-made in Stockport.
"Handcrafted" gets thrown around. At Dr Forest it's literal. Every organic fertiliser we sell is made by me, by hand, in a small unit in Stockport.
Batches stay small on purpose, usually between 50 and 250 kilograms. Small enough that I can check every input and pull a bag back if anything looks off.
01
Formulate
Start from a target Ca:Mg:K ratio and crop-specific brief. Work back to ingredients. NPK is the last number to land, not the first.
02
Weigh
Every input on calibrated scales. 0.5% increments. Spare inclusion goes into the Organic 3-2-2 blend rather than the bin.
03
Blend
Small batch, by hand, until visually homogeneous. Sample pulled from three points and checked before bagging.
04
Pack
Into kraft paper bags. Compostable inner liner. Batch number written on by hand. Shipped from the unit.
How It Started
Before the seaweed, there was a garden.
I've gardened since I was a kid. Before Dr Forest I cooked professionally for fifteen years, and that is where the flavour side of this fell into place. The chefs who shaped me, from Alain Passard to Simon Rogan, grow much of their own produce organically, and cooking with it you learn fast how much of the flavour is set by how a plant was grown. The trouble was always the feed. I could never get the ingredients I wanted; it was all mineral fertilisers.
Years ago I worked at Port Tocyn, a small hotel on the Welsh coast. I ran the beach most mornings, and what I couldn't get over was the seaweed, piled up after every tide, tonnes of it just sitting there. So I started making a seaweed feed in the fermenters I used for mead. Crude at first. I put a few bottles on eBay, and people bought them. That was the beginning of Dr Forest.
From there the range grew, mostly through single-ingredient amendments I had researched properly and could explain on the bag. By 2020 it was a proper business in Stockport. This year I started building custom crop-specific blends for tomato, rose, potato and strawberry, each one worked back from what the plant actually needs at every stage.
"Feed the soil, not the plant." Everything we make starts from that one principle.
I am still the only person who formulates, weighs, blends and packs every batch. The range has grown past seventy products, and the principle has not shifted.
— Joe
The Name
Dr Forrest. Two Rs, deliberately.
Dr Forest is named for my grandfather, Dr Forrest. He was a GP in a mining town near Preston his whole working life.
Outside the surgery he kept a vegetable plot in his back garden, and he made piccalilli from his runner beans for family and friends.
I dropped one R when I named the business. Forest, with one R, makes you think of nature, and trusting nature is the whole point of an organic fertiliser.
For family and friends.
The two-R spelling on the jar is for him. The one-R spelling on the bag is for the business.
Where To Start
Three places to begin, depending on what you're feeding.
Tomato & edibles fertiliser
Organic tomato fertiliser plus crop-specific blends for chillis, strawberries, potatoes and fruit-bearing veg.
Shop tomato & edible feeds
Rose & flower fertiliser
Organic rose fertiliser and Flower 3-3-6, plus the amendments that support them. Calcium and potassium in balance for stronger flowering.
Shop rose & flower feeds
Stage-feeding fertiliser · Veg & Bloom
Veg 4-4-4 organic fertiliser for vegetative growth. Bloom blends for flowering and fruiting. Switch between them as the plant moves through its cycle.
Shop veg & bloom feeds
Or browse the full range across 70+ organic fertilisers, amendments and biostimulants.
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From 3,250+ verified reviews by gardeners, allotment growers and smallholders across the UK.
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In The Press
Featured in the Telegraph, recommended in the Guardian.
Polyhalite, the mineral that keeps Wimbledon's grass courts alive, put Dr Forest in the Daily Telegraph. Over in the Guardian, Alys Fowler recommended our organic all-purpose feed by name in her column on overwintering citrus.
Recommended in
The Guardian
Gardening writer and former Gardeners' World presenter Alys Fowler recommended Dr Forest's organic all-purpose feed by name in her Guardian column on overwintering citrus, calling it "organic, made here in the UK, and full of good stuff."
Ready To Feed
Find the feed your plants have been missing.
Over seventy organic fertilisers, amendments and biostimulants, hand-blended in Stockport and built around the science on every product page.
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