Popul8, what it is and when to use it

March 21, 2025

Popul8, what it is and when to use it

Popul8 is a liquid from Neutrog that carries beneficial bacteria and fungi, and the idea behind it is that you're adding life to the soil rather than adding food to the plant. Healthy soil runs on microbes. They're what breaks organic matter down into the form a root can actually take up, so a soil with plenty of biology in it gets more out of the same amount of fertiliser than a dead one does.

What it does, honestly

A microbial inoculant seeds the soil with organisms. That's the whole job, and it's a real one, particularly in a bed that's been cropped hard for years or a new block where the topsoil got scraped off before the house went up.

What a bottle of microbes cannot do is survive in a soil with nothing to live on. Microbes need organic matter to eat and moisture to live in, so pouring them onto bare compacted clay in February is money down the drain, and that's the honest version rather than the one on the label. Get some compost or aged manure through the bed first, keep a mulch over the top so the surface doesn't cook, and then the inoculant has somewhere to live.

Run it that way and it's worth doing. Run it on its own and expect to be disappointed.

Where it earns its money

A new garden bed on a new block, where the soil is subsoil and there's no biology in it at all.
A vegetable patch that's been going for years and has started giving you smaller crops for the same effort.
Potted plants, where the mix is sterile to start with and stays that way.
Anything you've just transplanted, alongside a seaweed product to take the edge off the shock.

How to put it on

It's a liquid, so it dilutes and goes on through a watering can or a sprayer, and rates are on the bottle. Put it onto damp soil rather than dry, water it in afterwards so it gets down where the roots are instead of sitting on the surface in the sun, and try to do it in the cool of the morning or the evening. These are living organisms and full sun on a hot afternoon is hard on them.

It won't clash with your usual feeding. A pelletised fertiliser is doing a different job and the two work together perfectly well.

Shop related products

Popul8 1L. The liquid microbial inoculant this post is about.
Seamungus 500g. Seaweed and manure pellets, and the gentle one for anything transplanted or stressed.
Neutrog Rocket Fuel 6kg. The feed that does the plant side of the job.
Neutrog Whoflungdung Mulch 20kg. Keeps the surface cool and damp, which is what the microbes need to stay alive.

Did you know we also stock garden compost, mushroom compost and aged manures by the bag in the shop. They're not all on the website, so give us a ring on (08) 8536 4333 to check what's on the shelf.

The rest of the Neutrog range is in our garden centre, along with the wider garden range. We deliver Tuesdays and Thursdays on anything bought from us, $5 around Strathalbyn and $10 on the regional run. Local delivery.

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Popul8, what it is and when to use it