Gyganic for fruit and citrus trees, and when to use it

January 30, 2025

Citrus are hungry. That is the short version of why a lemon tree that gets fed twice a year fruits and a lemon tree that gets ignored sits there making leaves and yellowing off, and it is the reason a fruit and citrus fertiliser exists as its own bag rather than being folded into the general one.

Gyganic for Fruit and Citrus is an organic based granular fertiliser made for that job. It comes in a 4kg bag, and there is a smaller general Gyganic in 1.5kg that covers vegetables and ornamentals as well.

What it is doing

Feeding a fruit tree is a longer game than feeding a vegetable, because a tree is building wood and roots as well as fruit, and it is doing it in the same soil year after year. Organic based fertilisers suit that, since they release as the soil biology works on them rather than dumping everything available in one week.

It suits citrus in particular, so lemons, limes, mandarins, oranges and grapefruit, and it works on the deciduous fruit trees too. The general Gyganic covers vegetables, roses and ornamentals if you want one bag doing more than one job.

Where to put it

This is the bit people get wrong, and it costs them the feed. The feeder roots on a fruit tree are not at the trunk, they are out under the edge of the canopy, which is what gets called the drip line because that is where the rain falls off the outer leaves.

So spread the granules in a band around that outer edge and a bit beyond it, not in a pile against the trunk. Fertiliser heaped at the base can burn the bark and most of it is nowhere near the roots that could have used it.

Rake it in lightly if there is mulch down, pull the mulch back and put it on the soil, then pull the mulch over again. Water it in well afterwards.

When to feed

Citrus want two feeds a year in most South Australian gardens. One in late winter or early spring as the tree is waking up and setting flower, and one in late summer or early autumn to carry the fruit through and set the tree up for the next season.

A young tree in its first couple of years wants lighter and more often rather than one big hit, because the root system is small and cannot take up much at a time.

Follow the rate on the bag and go by the size of the tree. A tree with a canopy two metres across needs a lot more than a potted lemon on a patio, and the bag tells you how much.

Yellow leaves are not always hunger

Citrus yellow off for several reasons and only some of them are fixed with fertiliser, so it is worth a look before you spread anything.

Old leaves yellowing and dropping in winter is often just the tree doing what citrus do in the cold, and it corrects itself.
Yellow between green veins points at a trace element shortage, and magnesium is the common one. Epsom salts fix that and a general fertiliser will not.
Uniform pale yellow across the whole tree is usually nitrogen, and that is the one a feed does fix.
Yellowing with wet feet is drainage, and feeding a waterlogged tree makes things worse rather than better.

If you are not sure which of those you are looking at, pick a leaf and bring it in. That is a much quicker way to get an answer than working through a search page, and nobody minds a leaf on the counter.

Shop related products

Gyganic for Fruit and Citrus Trees 4kg. The one this post is about, for citrus and fruit trees.
Gyganic 1.5kg. The smaller all purpose bag, for vegetables, roses and ornamentals.
Manutec Magnesium Sulphate 1kg. Epsom salts, for the yellowing between the veins that a general feed will not shift.
Brunnings Potash Power 2.5kg. Potash for flowering and fruit set, where a tree is growing leaf and not much else.

Did you know we also stock Seamungus, Rapid Raiser, dolomite lime, gypsum 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 the fruit tree gear sit in the garden centre at H.