CalMag Fertilizer is a water-soluble plant nutrient used during active growth, flowering, and fruiting when plants need extra calcium and magnesium. It is especially useful for fruiting vegetables, container plants, indoor plants, flowers, roses, and home garden crops.
Calcium helps with new growth, root tips, stems, leaves, and fruit development. Calcium-related problems usually appear on young growth and fruits first.
Magnesium helps plants maintain healthy green leaves because it supports chlorophyll activity. Magnesium-related problems often appear as pale leaves or yellowing between green veins, especially on older leaves.
Calcium Issues
Calcium-related problems usually affect new growth and fruiting parts first.
Common signs include:
- Distorted, curled, or weak young leaves
- Tip burn on new leaves
- Poor root development
- Soft or weak new stems
- Blossom-end rot in tomatoes, chillies, capsicum, and similar fruiting crops
- Brown or sunken patches at the bottom end of fruits
CalMag can provide calcium, but watering also matters. If soil keeps switching from too dry to too wet, the plant may struggle to move calcium properly even when calcium is available.
Magnesium Issues
Magnesium-related problems usually appear first on older leaves.
Common signs include:
- Yellowing between leaf veins
- Green veins with pale yellow leaf areas
- Older leaves turning weak or yellow
- Poor leaf colour during active growth
- Pale plants after repeated watering in pots or grow bags
CalMag is useful when plants need both leaf colour improvement and fruiting-stage nutrition.
Benefits
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New growth: Helps support young leaves, shoots, stems, and roots
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Fruit development: Useful for tomatoes, chillies, capsicum, cucumbers etc.
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Leaf colour: Helps with magnesium-type yellowing on older leaves
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Water-soluble: Mixes easily for foliar spray or root-zone feeding
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Container use: Helpful where nutrients wash out faster with regular watering
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Dual nutrient: Provides calcium and magnesium in one product
How to Use CalMag Fertilizer
Foliar Spray
- Mix 5–10 grams in 1 litre of water.
- Spray lightly in the early morning or evening.
- Cover both upper and lower leaf surfaces where possible.
- Avoid spraying during hot sun, high heat, or plant stress.
- Repeat every 10–15 days only when needed.
- Test on a few leaves first, especially on sensitive indoor plants.
Soil Application
- Mix 5–10 grams in 1 litre of water.
- Apply around the root zone on moist soil.
- Use every 15–20 days during active growth if needed.
- Avoid overuse in small pots.
- Do not apply to already stressed or overwatered plants.
FAQs
When should I use CalMag Fertilizer?
Use it when plants show calcium or magnesium-related signs, such as weak young growth, tip burn, blossom-end rot risk, or older leaves yellowing between green veins.
Can CalMag help with blossom-end rot?
It can help provide calcium, but blossom-end rot is also linked with irregular watering, heat stress, and poor calcium movement inside the plant. Keep soil moisture steady.
Why are my leaves still yellow after using CalMag?
The yellowing may not be from magnesium deficiency. Overwatering, poor drainage, low nitrogen, iron deficiency, pests, disease, and root stress can also cause yellow leaves.
Should I spray CalMag or apply it to soil?
Use foliar spray for faster leaf support. Use soil application for root-zone feeding, especially in pots and grow bags.
How often should I use CalMag?
Use every 10–15 days as foliar spray or every 15–20 days as soil application only when needed. Do not use it as daily watering.
