Just 50 g per square metre of seabird guano can double flower mass in tomatoes—yet most gardens still limp along on synthetic phosphorus. If you want bigger roots, heavier fruit and tougher plants without the chemical usage, read on.
What exactly is Seabird Guano?
Seabird guano is naturally mineralised seabird droppings that have hardened on coastal rocks over centuries. Unlike bat guano (often higher in nitrogen) or chicken manure (low phosphorus), seabird guano is loaded with slow-release phosphorus, calcium and silica—the trifecta for roots, blooms and resilience.
Why Gardeners Swear by It
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Phosphorus punch – drives explosive root initiation and flower/fruit set.
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Calcium fortress – firmer fruit, less blossom-end rot, stronger cell walls.
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Silica shield – thicker stems, better drought and heat tolerance.
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Microbe magnet – feeds beneficial soil biology for months.
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Low odour & kid-safe when used as directed.
Nutrient Breakdown (Dry vs Liquid)
|
Product |
N |
P |
K |
Ca |
Si |
Notes |
|
0.11 % |
11.17 % |
0.25 % |
34.79 % |
8.8 % |
50 % immediate, 50 % slow-release P |
|
|
< 0.5 % |
6.26 % |
1.57 % |
13.3 % |
— |
Ultra-fine, drip-safe concentrate |
Dry vs Liquid—Which One for You?
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Dry Seabird Guano
Best for bed preparation, fruit trees and long-season crops. Scratch 50–100 g /m² into soil or 250–400 g per mature tree for a six-month feed. -
BioGuano+ Liquid
Perfect for containers, fertigation and mid-season boosts. Dilute 10 ml per litre of water and drench soil every 2–4 weeks.
Many growers run both: dry guano at planting, then liquid BioGuano+ through flowering.
If you prefer a more microbe-focused approach before bringing in phosphorus, Worm Castings Australia: The Complete Gardener’s Guide covers how castings build the biological foundation guano thrives on.
Application Rates & Timing
|
Crop / Situation |
Dry Guano (g /m²) |
Liquid BioGuano+ (ml /L) |
When to Apply |
|
Veggie beds |
50–100 |
10 |
Bed prep; pre-flower |
|
Fruit trees |
250–400 per tree |
15 (soil drench) |
Early spring & mid-summer |
|
Potted plants |
1–2 tsp per 10 L mix |
5 |
Monthly during growth |
|
Lawn starter |
60 |
10 |
Before seeding or top-dress |
Heads-up for natives: Proteas, banksias and other P-sensitive Aussie natives need only a pinch—or skip guano altogether.
Pro Tips for Maximum Pay-off
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Water in deeply after spreading to pull minerals into the root zone.
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Mulch over the top-dress to lock moisture and microbes in.
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Pair with balanced N/K sources (e.g. fish & kelp) to keep growth even.
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Brew a quick “guano tea”—2 tbsp dry guano in 4 L water, aerate 24 h, strain, drench.
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Monitor pH: guano is mildly alkaline. Already got high-pH soil? Use the lower rate.
For a full breakdown of how kelp supports guano-driven flowering and root growth, see our Kelp Meal: Australia’s Ocean-Powered Fertiliser (2025 Guide).
FAQs
How long does seabird guano feed for?
Up to six months thanks to the slow-release phosphorus fraction.
Will it burn plants?
Only if you go way overboard. Stick to the rates above.
Is it safe for edibles?
Absolutely. Brush off any granules from leaves and water in.
Can I use it in hydroponics?
Liquid BioGuano+ runs in drip lines; dry guano does not—save that for soil.
Does it smell?
Barely. Any earthy whiff disappears once watered in.
Storage life?
Years. Keep the bag or bottle sealed in a cool, dry spot.
Does guano change soil pH?
Slightly alkaline. It won’t swing pH hard at the recommended rates.
Can I mix it with other amendments?
Yes—compost, worm castings, fish and kelp all play nicely. Just watch total phosphorus.
If you want to boost immunity while keeping P levels steady, Insect Frass 101: The Aussie Gardener’s Secret Weapon explains why frass is the go-to chitin source for pest resilience.
Ready to Boost Your Beds?
Grab your weapon of choice and watch the roots explode:
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Certified Organic Seabird Guano (500 g – 2.5 kg) – slow-release P & calcium for six-month stamina.
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BioGuano+ Liquid (1 L / 5 L) – drip-safe concentrate for rapid uptake.
Order before 12 pm for same-day dispatch Australia-wide. Your plants (and taste-buds) will thank you. 🌱
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