Neutrog Upsurge, what it is and when to use it

January 28, 2025

Upsurge is Neutrog's general garden fertiliser, and the reason it gets recommended across the counter as often as it does is that it is one of the few bags that genuinely suits most of what people are growing rather than one narrow job.

It is organic based and it comes as a crumble, which is somewhere between a granule and a pellet. That form is the practical difference with this one, because a crumble spreads evenly by hand without the fine dust of a powder and without the fiddle of breaking up pellets.

What it suits

Vegetables, fruit trees, flowers, shrubs and ornamentals. It is the bag you reach for when you want to feed a whole bed rather than target one plant, and it works in the ground and in pots.

Being organic based means it is feeding the soil life as well as the plant, so it builds something up over a season rather than only delivering a nutrient hit. On the sandy soils around here that matters, because the organic matter is the part that washes out first and it is the part holding the water and the nutrients in place.

How to put it on

Spread it evenly over the soil surface, around the drip line of a tree or shrub rather than up against the trunk, and then water it in properly so it starts breaking down into the soil instead of sitting dry on top.

Follow the rate on the bag. It is tempting to be generous with a fertiliser that is gentle, and it is still wasted money past the point the plants can use it.

Mulch over the top afterwards if the bed is going to be sitting through hot weather, because the fertiliser and the mulch are doing complementary jobs and the mulch keeps the soil biology working while the surface would otherwise bake.

When to feed

Feed when things are growing. Early spring as everything wakes up, again through the growing season for anything cropping heavily, and a lighter feed in autumn for the perennials going into winter. Feeding a plant that is dormant does very little except cost you the fertiliser.

Seedlings are the exception worth naming. Go light around anything freshly planted, or put the fertiliser through the bed a week or two before you plant into it, since tender roots and a full strength feed do not get along.

When something else is the better bag

Upsurge is a generalist and there are jobs where a specialist does better.

Lawns want a lawn fertiliser, because the balance is different and a lawn is mostly leaf.
Roses have their own formulation and it is worth using on an established bed.
Citrus and fruit trees have their own too, particularly once they are cropping.
Acid loving plants such as azaleas, camellias and blueberries want something formulated for them.
A soil pH problem is not a feeding problem at all, and no amount of fertiliser fixes it. Test first.

If you are standing in front of the shelf trying to work out which bag is yours, just ask us. Tell us what you are growing and what the soil is like and we will point at one, which takes a couple of minutes and saves you buying the wrong 20kg bag and carrying it home.

Shop related products

Neutrog Upsurge Crumble 20kg. The big bag, for a whole garden or a run of beds.
Neutrog Rapid Raiser 20kg. The other Neutrog all rounder, if you want a pellet rather than a crumble.
Neutrog Whoflungdung Mulch 20kg. Goes over the top to keep the soil cool and the biology working.
Neutrog Seamungus Liquid Concentrate 1L. A liquid tonic for anything stressed, between the granular feeds.

Did you know we also stock Upsurge in the smaller 7.5kg bag, Seamungus in 500g, 10kg and 20kg, Gyganic, and soil pH test kits in the shop. Not all of it is on the website, so give us a ring on (08) 8536 4333 to check what is on the shelf.

The rest of the fertilisers and soil improvers sit in the garden centre at H, with the Neutrog range in its own section.