An apple tree that bears fruit every year — without alternate bearing. Fruit that is deep red, intensely fragrant, and packed with quercetin and phloridzin at 14 to 18 °Brix. A tree that needs only half as many sprays as the neighbor. And after three treatments with GRÜNKRAFT Calcium, the fruit is more evenly ripened, more aromatic, and keeps longer than ever before.
This is no wishful thinking. These are measured results from our European field studies.
And the beauty of it: The principle behind it does not only apply to apple trees. It applies to every fruit tree — pear, cherry, damson, quince, apricot. Everywhere a tree bears fruit that is intended to contain polyphenols, vitamins, and secondary plant compounds, the work begins in the soil and with foliar feeding.
The problem — why apple trees need so much plant protection
Apple scab is one of the most common apple tree diseases worldwide and the main crop pest in Austrian apple growing. The fungus Venturia inaequalis loves damp conditions — in wet years, the pressure explodes. And it preferentially attacks stressed trees.
Here lies the key. A stressed tree — calcium deficiency, poor soil life, depleted soil — cannot maintain its own immune defense. Its cell walls are thin, its stomata poorly regulated, its polyphenol production limited.
Organic fruit growers use sulfur products, baking soda, and acid clay alongside copper to combat scab. Unlike synthetic fungicides, which penetrate the plant, these active ingredients remain on the surface. For this reason, they are washed away by the rain and must be reapplied regularly.
This means: The conventional way is a cycle. The tree is weakened — so it is sprayed — the spraying stresses the soil — the soil nourishes the tree less effectively — the tree becomes weaker — so more is sprayed.
The other way begins with the soil and the tree itself.
The most common apple diseases and pests — what lies behind them
Apple scab — Venturia inaequalis: Dull olive-green, later blackish spots on leaves and fruit. Star-shaped cracks on the fruit. The fungus loves moisture and warm temperatures. It first attacks stressed, calcium-deficient trees.
Powdery mildew — Podosphaera leucotricha: Whitish coating on young leaves and shoots. Typically in dry weather and high humidity. Healthy trees with stable cell walls are significantly more resistant.
Fire blight — Erwinia amylovora: The most feared bacterial disease in fruit growing. Affected shoots and blossoms look as if they have been burned. It spreads quickly in warm, damp periods. It preferentially attacks lushly grown, nitrogen-overfertilized shoots — a well-balanced mineralized tree is less susceptible.
Codling moth — Cydia pomonella: The caterpillar of the small moth penetrates the fruit and destroys the core. In the so-called confusion method, pheromones are hung on dispensers in the apple orchard to attract males so that they do not find the females. This method also works in the home garden.
Woolly aphid — Eriosoma lanigerum: Sucks on bark and shoots, leaving characteristic white woolly webs. Prefers trees with a low Brix value — the same principle as with all sucking insects.
Spider mites: Especially in hot summers. They suck the leaf contents out — the leaves turn bronze. Healthy trees with the physical protective film of GRÜNKRAFT Zeolith Pur on the leaves are significantly less infested.
The program — how an apple tree becomes healthy
Step 1 — Soil preparation: BODENKRAFT PUR + Steinkraft Basalt
Timing: In autumn or early spring — before bud break.
BODENKRAFT PUR is tribomechanically ground zeolite with an intact crystal lattice structure. Particularly important for apple trees: It holds calcium and potassium in the root zone — exactly the two minerals that control polyphenols and secondary plant compounds in the fruit. And it buffers water fluctuations — drought stress is one of the main triggers for weak scab defense.
Steinkraft Basalt with its paramagnetic properties provides the broad spectrum of trace elements that an apple tree needs over decades — silicon for cell wall stability, iron, manganese, copper, zinc. The paramagnetic effect triples the microbial environment in the soil — and an active soil life is the best long-term prevention against fungal diseases.
Application in the orchard: Work 300–400 kg/ha + Steinkraft Basalt 300–500 kg/ha into the soil. In older, depleted orchards, up to 1,000 kg of basalt in the first year.
In the garden: Per apple tree, rake in one generous shovel of BODENKRAFT PUR and one shovel of basalt granules around the trunk — in the area of the crown projection — flatly. Once a year in autumn or spring.
Step 2 — Activate soil life: AM+PLUS microorganisms
Timing: In spring at bud break — and thereafter every 3 to 4 weeks.
AM+PLUS is the organic solution from Austrian organic herbs, based on lactic acid bacteria, refined with homeopathy and spagyrics. Particularly important for apple trees: The microorganisms in AM+PLUS compete with scab spores and other fungal pathogens for the same niches on the soil and leaf surface. An active, diverse soil microbiome protects the tree from below.
Customers also report: With the combination of basalt, zeolite, and AM+PLUS, slugs disappear from the garden. And the soil life regenerates visibly — earthworms return, the soil becomes looser.
Application: As a soil drench around the tree in spring, then every 3 to 4 weeks. Also as a foliar spray on leaves and fruit.
Step 3 — Foliar feeding: GRÜNKRAFT Calcium from bud break
Timing: At the first green — before flowering. This is the crucial moment.
GRÜNKRAFT Calcium is tribomechanically pulverized calcite with natural zeolite in a particle size under 8 µm. Stomata-compatible — the particles penetrate through the leaf pores and decompose into CO₂ for photosynthesis and calcium for the cell walls.
For apple trees, it works on three levels simultaneously:
First, calcium directly strengthens the cell walls — thin-walled cells are the gateway for scab fungi. More stable cells mean fewer infection points.
Second, calcium regulates the stomata — closed or well-regulated leaf pores take in fewer fungal spores.
Third, the CO₂ supply intensifies photosynthesis — and more photosynthesis means more quercetin, more phloridzin, more chlorogenic acid in the fruit. The Brix value rises. The polyphenols rise.
In the European field studies with activated calcite: Treated apple trees had more evenly ripened fruit, earlier ripening, a higher dry matter content — and the pesticide requirement could be halved in some cases.
GRÜNKRAFT Calcium can be easily combined with all commercially available plant protection and fertilizers — this greatly simplifies the spraying program.
First application at bud break: 5g per 1 liter of water. From the second application every 10-14 days: 20-30g per 1 liter of water. Spraying time: Early morning or late afternoon when the stomata are open.
Step 4 — GRÜNKRAFT Zeolith Pur as a physical protective film
Timing: Parallel to GRÜNKRAFT Calcium — from the first green.
GRÜNKRAFT Zeolith Pur forms a physical protective film on the leaf surface. The ultra-fine silicate particles act as a natural repellent against spider mites, aphids, and woolly aphids — through a purely physical process. At the same time, it brings silicon into the leaf that strengthens the cell walls against fungal diseases.
Spray again immediately after heavy rain — the protective film is washed away and must be renewed. Organic fruit growers do exactly the same with copper and sulfur — except that GRÜNKRAFT Zeolith Pur leaves no heavy metal load in the soil.
The treatment schedule for apple trees
Autumn or early spring: Work BODENKRAFT PUR + Steinkraft Basalt around the tree.
Bud break — first treatment: GRÜNKRAFT Calcium 5g/l + AM+PLUS as a soil drench.
Before flowering — the most critical phase!: GRÜNKRAFT Calcium 20-30g/l + GRÜNKRAFT Zeolith Pur. In the blossom, the fruit quality of the entire year is decided.
After flowering every 10-14 days: GRÜNKRAFT Calcium 20-30g/l + GRÜNKRAFT Zeolith Pur.
Fruit development: Continue treating — the polyphenols build up in the fruit until full ripeness. Every treatment increases the Brix value and nutrient density.
Every 3-4 weeks: AM+PLUS as a soil drench or foliar spray.
After rain: Renew GRÜNKRAFT Zeolith Pur immediately.
For the garden — one tree, made easy
An apple tree in the garden is a gift for decades. Here is the simplified plan:
In autumn or spring around the tree: Rake in one shovel of BODENKRAFT PUR and one shovel of basalt granules flatly. This then remains active in the soil for years.
At the first green in spring: AM+PLUS into the watering water and water around the tree. Then repeat every 3 to 4 weeks.
From bud break every 10-14 days: Spray bottle or garden sprayer with GRÜNKRAFT Calcium — 20-30g per 1 liter of water. Spray the whole tree — leaves top and bottom, young shoots, and when the fruit sets, the fruit itself too.
GRÜNKRAFT Zeolith Pur in parallel — especially if mildew or mites are threatening.
After rain: Spray again immediately. This is the only effort that really counts.
What you will observe over the years: The fruit will be more evenly ripened. The smell will become more intense. The shelf life increases — an apple with 18 °Brix keeps in the cellar significantly longer than one with 8 °Brix. And the alternate bearing — the annual skipping of the harvest — will decrease. A vitally supplied apple tree bears fruit every year.
And this applies to all fruit trees
The principle is always the same — whether apple, pear, cherry, damson, apricot, quince, or grapevine.
All fruit trees need calcium for stable cell walls and disease resistance. All benefit from an active soil microbiome that makes minerals available. All form more secondary plant compounds — more polyphenols, more anthocyanins, more aromatic compounds — when they perform intensive photosynthesis. And all show the effect in the Brix value of the fruit.
The dosages remain the same. The timing adapts to the respective crop — start at bud break, repeat every 10-14 days, react immediately to stress.
What changes is the starting situation of each crop — cherry reacts differently to moisture than damson, apricot has different fungal diseases than apple. But the core remains: A vital plant from healthy soil needs less protection from the outside, because it protects itself.
This is regenerative fruit culture. This is the way back to the real apple — the apple that truly justifies "an apple a day keeps the doctor away".
The complete program at a glance
| Phase | Measure | Product | Timing |
|---|---|---|---|
| Autumn/Spring | Activate soil | PURE SOIL POWER + Basalt Rock Power | Once a year |
| Sprouting | Start soil life | AM+PLUS | At the first green |
| Bud break | First foliar feeding | GRÜNKRAFT Calcium 5g/l | Immediately |
| Before flowering | Treat intensively | GRÜNKRAFT Calcium 20-30g/l + GRÜNKRAFT Pure Zeolite | Every 10-14 days |
| Fruit development | Continue treatment | GRÜNKRAFT Calcium 20-30g/l + GRÜNKRAFT Pure Zeolite | Every 10-14 days |
| After rain | Renew protective film | GRÜNKRAFT Pure Zeolite | Immediately |
| Entire season | Maintain soil life | AM+PLUS | Every 3-4 weeks |
Links — all products and further information
All products for the garden in our Garden Collection.
For fruit farms, all products in the Agriculture Collection.
What quercetin, phloridzin and pectin are — and why heirloom apple varieties have six times more polyphenols — in the Apple Nutrient Article.
Why paramagnetic basalt triples soil life — Basalt Blog Post.
Correct use of zeolite in the garden — the comprehensive guide.
Measuring the Brix value — instructions and Reams table — Brix Article.
Why food today has fewer nutrients — Article on minerals and depleted soils.
Sources: Land schafft Leben, Apfel Boden pflegen Pflanzen schützen | Schrot & Korn, Äpfel Bios spritzen anders 2022 | hausgarten.net, Apfelschorf bekämpfen | Oekomineral Group / Tribo Technologies, Field studies Apple Megagreen/Plantos Verde 2011–2014 — yield increase of up to 50%, reduced pesticide requirement, improved dry matter content | steinkraft-naturerocks.com, Product information GRÜNKRAFT Calcium, GRÜNKRAFT Pure Zeolite, PURE SOIL POWER, AM+PLUS | Philip S. Callahan, Paramagnetism — Rediscovering Nature's Secret Force of Growth
