Berries are rewarding, but they have different demands, and that is exactly where many go wrong. Whoever treats all bushes the same over-fertilises some and mis-fertilises others. Especially with the sensitive acid-lovers, the well-meant handful of all-purpose fertiliser often does more harm than good.
The good news: you need not memorise a complicated recipe. It is enough to sort your berries into a few groups and give each the right thing. This article gives you exactly that simple plan.
No feeding by one measure
The key is to sort the berries by their need. Some want acid soil and react sensitively to lime, others are hungry for potassium, others again get by on very little. Whoever knows these three groups does almost everything right.
As a rule for all: fertilise organically in spring, cover the soil with a layer of mulch and give no more nitrogen after high summer. Late nitrogen drives soft wood that does not ripen and freezes in winter.
The berry groups and their needs
- Acid-lovers: blueberry and co.
Blueberries, lingonberries and cranberries need acid soil. No lime, no mineral all-purpose fertiliser, no hard tap water. Only special berry or rhododendron fertiliser and rainwater.
- Heavy feeders: currant and gooseberry
The Ribes berries are hungry, above all for potassium for sweet fruit. Ripe compost in spring plus an extra portion of potassium-rich organic fertiliser does them good.
- Light feeders: raspberry and blackberry
The cane berries are undemanding. A layer of mulch from compost or leaves is usually enough. Too much nitrogen gives lots of leaf and soft, disease-prone canes.
- Strawberry: the second feed counts
Strawberries are fertilised moderately in spring, but the more important feed comes after harvest, when the plant lays down the buds for next year.
How you fertilise berries correctly
Start organic in spring
Spread ripe compost around each bush and work it in shallowly, plus, for heavy feeders, a little horn shavings for the slow nitrogen supply.
Mulch
A layer of leaves, grass clippings or compost on the soil holds moisture, suppresses weeds and feeds the soil life. For cane berries often the whole fertilising.
Treat acid-lovers separately
Never supply blueberries with lime or all-purpose fertiliser. Give only acid berry or rhododendron fertiliser and water with rainwater.
Stop after summer
From about late July no more nitrogen. The wood must ripen to become winter-hardy. A potassium feed in late summer, by contrast, improves the frost hardiness.
Sort by need: acid-lovers acid, Ribes potassium-rich, cane berries only mulched. And after high summer no more nitrogen.
The core rule for fertilising berries
Frequently asked questions
Can I supply all berries with the same fertiliser?
Better not. The need differs strongly. Acid-lovers like blueberries tolerate no lime and no all-purpose fertiliser, currants and gooseberries are potassium-hungry, raspberries and blackberries undemanding. One all-purpose fertiliser for all harms the sensitive types.
What do you fertilise blueberries with?
Only with special acid berry or rhododendron fertiliser. Blueberries are bog-bed plants and tolerate no lime, no mineral fertiliser and no hard tap water. Mulch with pine litter or bark mulch and water with rainwater, that keeps the soil acid.
When do you fertilise berry bushes?
The main feed happens in spring with ripe compost and a little horn shavings. After high summer, from about late July, you give no more nitrogen, so the wood ripens and becomes winter-hardy. A potassium feed in late summer improves frost hardiness.
Why do my blueberry's leaves turn yellow?
Usually the soil pH is too high, often from lime out of compost or hard watering. The plant can then not take up iron, the leaves yellow between the veins. Acid fertiliser, bark mulch and rainwater put it right.
Do raspberries and blackberries need much fertiliser?
No, they are undemanding. A layer of mulch from compost or leaves is usually entirely enough. Too much nitrogen only promotes soft, disease-prone wood and lots of leaf instead of fruit. With cane berries less is often more.
