John Innes compost confuses a lot of gardeners, mainly because of the numbers. The short version: John Innes is not a brand but a traditional loam-based recipe, and the numbers tell you how much feed each mix contains, matched to the stage of the plant rather than the amount you use. Get the right one for the job and you have a firm, reliable, nutrient-rich compost that holds its feed far longer than a bag of multipurpose. Here is what each grade is for.
By Kel, Senior Brand Marketing Manager at Gro Worm. Reviewed by Brian McCuskey, Owner. Updated August 2026.
What is John Innes compost?
John Innes is a set recipe developed at the John Innes Institute in the 1930s, which is why any brand can make it. What defines it is that it is loam-based: it blends sterilised soil with other ingredients to give a firm, heavier growing medium, rather than the light, soilless mix you get with multipurpose compost.
That soil base is the whole point. Because it is loam-based, John Innes holds on to nutrients and moisture well, resists drying out, and gives pots real weight and stability, which matters for taller plants and long-term container growing. It is the compost to reach for when a plant is going to live in the same pot for months or years.
What is the difference between John Innes No.1, No.2 and No.3?
The numbers refer to the level of feed in the compost, and they follow the plant as it grows and gets hungrier. They are not about how much to use.
No.1 is the gentlest, with the lowest level of nutrients. It is for young plants and seedlings being potted up for the first time, where too much feed would do more harm than good. No.2 has more feed and is the general workhorse, ideal for potting on established plants, repotting houseplants and growing vegetables. No.3 is the richest of the three, made for mature plants, hungry crops such as tomatoes, shrubs and final potting into large containers where the plant will stay put and needs plenty in reserve.
Alongside the numbered grades sit two specialists. The Seed compost is finer and lower in nutrients still, for sowing seeds and taking cuttings, and the Ericaceous mix is a John Innes compost with a lowered, acidic pH for lime-hating plants.
Which John Innes should I use?
A simple way to think about it is to follow the plant through its life. Sow into John Innes Seed compost. Prick seedlings out and pot them up into No.1. As they establish and fill their pots, move them on into No.2. When they reach their final large container, or if they are a hungry, long-lived plant from the start, use No.3.
For acid-lovers such as rhododendrons, camellias and blueberries, skip the numbered grades and use the ericaceous version instead, whatever their size, because pH matters more to those plants than feed level.
Is John Innes better than multipurpose compost?
Neither is better outright; they suit different jobs. Multipurpose is light, cheap and convenient, and it is fine for short-term bedding, quick container displays and general use. Loam-based John Innes holds nutrients and water for longer, resists drying out, and anchors heavier plants, which makes it the stronger choice for potting on and for anything staying in its pot for the long haul. Plenty of gardeners keep both to hand and match the compost to the plant and the pot.
What makes Gro Worm's John Innes range different
Ours pairs the trusted John Innes recipe with high-potency Gro Worm worm casts. That means you get the structure and staying power of a loam-based compost, plus the beneficial microbes and micronutrients that worm casts bring, which support strong root development and healthy growth. The range is certified organic by OF&G and comes in convenient 8 litre handy packs across the full set, from Seed to No.3 and Ericaceous, so you can match the mix to every stage without hauling a huge bag around. You can see the whole range on the John Innes collection.
Frequently asked questions
What is John Innes compost?
John Innes is a traditional loam-based recipe, not a brand. It blends sterilised soil with other ingredients to make a firm, nutrient-rich compost that holds feed and moisture well, which suits potting and long-term container growing.
What is the difference between John Innes No.1, No.2 and No.3?
The numbers show how much feed each mix contains, matched to the plant's stage. No.1 is the gentlest for young plants, No.2 has more feed for potting on established plants, and No.3 is the richest for mature plants, hungry crops and final potting.
Which John Innes should I use for seeds?
Use John Innes Seed compost for sowing seeds and taking cuttings. It is fine textured and low in nutrients, which is what seedlings need. Move them into No.1 once they are large enough to handle.
Is John Innes peat-free?
This depends on the specific product, so check the individual product page. What all our John Innes mixes share is that they are enriched with Gro Worm worm casts and certified organic by OF&G.
Is John Innes better than multipurpose compost?
For potting on and long-term container plants, loam-based John Innes usually wins because it holds nutrients and water longer and gives heavier plants stability. Multipurpose is lighter and fine for short-term and general use. Many gardeners use both.
Match the mix to the plant
The John Innes system takes the guesswork out of potting once you know the numbers. Our John Innes range covers every stage from seed to mature plant, each one worm-cast enriched and certified organic, in a handy 8 litre pack that is easy to store and easy to use.
