A streamlined organic feeding program for soil-grown cannabis using Neptune's Harvest liquid fertilizers — from seedling to final flush, infused with Kānehiwa's island wisdom.
🌊
Feed the soil, not the plant. Neptune's Harvest is cold-processed and hydrolyzed — the nutrients are broken down into forms that soil microbes can immediately convert into plant-available nutrition. Shake well before every pour.
🌿Type Organic Liquid
📅Duration 10 Weeks
🪴Medium Soil / Living Soil
📊Level Beginner
🧪 Product Lineup
Seaweed Plant Food
0 – 0 – 1
High in cytokinins for root development. The gentle starter — won't burn seedlings.
Tomato & Veg Formula
2 – 4 – 2
Humic acids and yucca extract for nutrient uptake. The vegetative workhorse.
Fish & Seaweed Blend
2 – 3 – 1
Transition formula — bridges veg to bloom with balanced macro and micronutrients.
Rose & Flowering
2 – 6 – 4
High phosphorus for bud density and volume. The bloom engine.
✨ Optional Boosters — Bloom City
Earthworm Tea Concentrate
Compost & Bokashi Booster
Concentrated castings tea loaded with beneficial microbes, humic acids, and natural growth hormones. Use as a soil drench between Neptune's feedings to supercharge your soil biology — the microbes are what make organic nutrients plant-available.
Root Stimulant
Salmon & Kelp Formula
Rich with mycorrhizae and beneficial microbes that colonize the root zone, expanding the plant's ability to absorb nutrients and water. Salmon provides amino acids and kelp provides cytokinins for explosive root growth.
📅 When to Use
Earthworm Tea Concentrate — Use as a soil drench once per week throughout the entire cycle, alternating with Neptune's feedings. Apply on "off" days when you're not feeding Neptune's. Especially effective during Weeks 2–4 (veg) when soil biology is building, and again during Weeks 6–8 (bloom) when nutrient demand peaks. Follow the dilution rate on the Bloom City label.
Root Stimulant — Apply at transplant and during the first 3 weeks of each phase transition. Use at transplant (moving from solo cup to final pot), at the start of Week 2 (when switching to Tomato & Veg), and at the start of Week 5 (transition to bloom). The mycorrhizae need time to colonize — early application gives them a head start before heavy feeding begins. Follow the dilution rate on the Bloom City label.
🌺 Hawaiʻi Island Tip — Bloom City in the Tropics
Maui's warm soil temps (75–82°F) are ideal for microbial products — the beneficial bacteria and mycorrhizae in both Bloom City products colonize 2–3× faster than in cooler mainland soils. This means you'll see results sooner, but it also means the products degrade faster once diluted. Mix and apply immediately — never let diluted microbial products sit in a bucket. Store concentrate bottles in a cool, dark place (not the garage). The Root Stimulant is especially valuable at transplant on Maui, where the intense sun and heat amplify transplant shock — strong mycorrhizal networks help the plant recover by expanding water uptake before the roots have fully established.
📋 10-Week Schedule
Stage
Week
Product
Rate / Gal
I. Seedling
1
Seaweed(0-0-1)
½ oz (15ml)
II. Vegetative
2
Tomato & Veg(2-4-2)
1 fl. oz (30ml)
II. Vegetative
3
Tomato & Veg(2-4-2)
1 fl. oz (30ml)
II. Vegetative
4
Tomato & Veg + Seaweed
½ oz each
III. Transition
5
Fish & Seaweed Blend(2-3-1)
1 fl. oz (30ml)
IV. Bloom / Flower
6
Rose & Flowering(2-6-4)
1 fl. oz (30ml)
IV. Bloom / Flower
7
Rose & Flowering(2-6-4)
1 fl. oz (30ml)
IV. Bloom / Flower
8
Rose & Flowering(2-6-4)
1 fl. oz (30ml)
V. Ripening
9
Rose & Flowering + Molasses
½ oz / 1 tsp
VI. Flush
10
Clean Water Only(No Nutrients)
—
📖 Detailed Application Guide
1
Seedling Phase — Week 1
Wait until your plants have their first set of true leaves before feeding. Neptune's Seaweed (0-0-1) is high in cytokinins which helps root development without burning the delicate young plant. At half an ounce per gallon, this is a gentle introduction — just enough to signal the roots to start exploring.
🌺 Hawaiʻi Island Tip — Seedlings in the Tropics
Maui's warm soil temps (75–82°F) mean seedlings establish roots faster — you may see true leaves by day 4–5 instead of day 7. Start the seaweed drench as soon as the first true leaves unfurl, not on a fixed calendar day. Hawaiʻi's ambient humidity makes damping-off the #1 seedling killer on the islands — ensure good drainage in your solo cups, keep a gentle fan running, and avoid overwatering on top of the already-humid air.
2
Vegetative Phase — Weeks 2–4
During veg, the plant needs nitrogen and structural support for stem mass and leaf expansion.
🔄 The Switch
Move to Tomato & Veg (2-4-2) at 1 fl. oz per gallon. This formula includes humic acids and yucca extract that improve nutrient uptake in the root zone — the yucca acts as a natural wetting agent that helps the drench penetrate evenly through your soil.
🍃 The Foliar Option
In Week 4, switch to a light foliar spray of Seaweed + Tomato & Veg (½ oz each per gallon). This thickens the leaves and prepares them for the stretch that comes with the flip to flower. Spray the undersides of leaves where stomata are most concentrated.
🌺 Hawaiʻi Island Tip — Veg Moves Fast on Maui
Plants veg 20–30% faster in Hawaiʻi's warmth — a 4-week mainland veg can be 3 weeks here. Watch node count, not the calendar. If you're at node 5–6 by Week 3, consider flipping early. For the Week 4 foliar spray, do it before 7 AM — Maui's UV intensity after 8 AM can burn coated leaves. If your plants look hungry mid-veg, bump Tomato & Veg to 1.5 fl. oz per gallon — the faster growth rate in tropical conditions demands more nitrogen.
3
Bloom Phase — Weeks 5–9
Once the first white hairs (pistils) appear, shift the focus to Phosphorus and Potassium.
🔄 The Switch
Move to Rose & Flowering (2-6-4) at 1 fl. oz per gallon. The high phosphorus drives bud density and volume, while the potassium strengthens cell walls and improves resin production.
🍯 The Sweetener — Week 9
In the final feed week, add 1 teaspoon of unsulphured blackstrap molasses per gallon alongside a half-dose of Rose & Flowering. The molasses feeds the microbial life in your soil — the same biology that makes nutrients plant-available. This is what increases the "frostiness" (trichome density) and the complexity of the final product.
🌺 Hawaiʻi Island Tip — Bloom in the Tropics
Maui's ambient heat (78–85°F) accelerates flower development — buds swell faster but also degrade faster if temps aren't managed. Run lights at night to keep peak flower temps under 82°F. The molasses trick in Week 9 works even better here because our warm soil biology processes sugars faster, creating a bigger microbial bloom. Consider adding Neptune's Seaweed at ¼ oz per gallon alongside Rose & Flowering during Weeks 6–8 — the extra potassium and trace minerals strengthen cell walls against Maui's humidity-driven bud rot.
4
The Final Flush — Week 10
Because Neptune's Harvest is organic and hydrolyzed, it doesn't leave heavy mineral salts like synthetic nutrients. However, a 7-day flush with plain water is still recommended to ensure the smoothest smoke and cleanest flavor. Water until you see 15–20% runoff each time to push any remaining organic residues through the root zone.
🌺 Hawaiʻi Island Tip — Flushing on the Islands
Use pH-adjusted water (6.2–6.5) for the flush — Maui county water runs pH 7.8–8.4, too alkaline even for plain watering. A splash of brown rice vinegar or citric acid brings it down naturally. During the flush, watch humidity carefully — the heavy watering in an already-humid climate can push tent RH past 65% during late flower, inviting bud rot. Run your dehu harder during Week 10.
💡 Essential Application Tips
1
Preparation
Neptune's Harvest contains highly hydrolyzed organic material that will settle.
Shake Well: Always shake the bottle intensely before measuring. The active ingredients — amino acids, cytokinins, and trace minerals — settle to the bottom. If it's been sitting for weeks, give it a full minute of vigorous shaking.
Mix & Use: Organic liquids will begin to ferment and lose potency very quickly once diluted. Never store a pre-mixed bucket — mix fresh every time and apply immediately.
2
Foliar Application
While this chart is a drench schedule, Neptune's (especially the Fish & Seaweed Blend) is an exceptional foliar feed.
Early/Late Spray: Only foliar spray in the early morning (before 9 AM) or just before sunset (after 6 PM) to prevent leaf burn. Oil droplets on leaves act as tiny magnifying lenses under direct light.
Stop Spraying: Stop all foliar sprays once you see the first white hairs (pistils) of flower to prevent mold in the buds. From Week 5 onward, drench only.
3
Soil & pH
Neptune's will stabilize your soil microbiology, but it is not a "buffer" for hard water.
pH Target: Aim for a final mixed pH of 6.2–6.8 for optimal drench uptake in soil. Always test your final solution before applying.
Seaweed & Stress: Use the Seaweed (0-0-1) by itself (drench or spray) anytime you see signs of transplant shock, heat stress, or wind damage. The cytokinins and trace minerals act as a natural recovery booster — it's the gentlest product in the lineup and can be used as a standalone rescue treatment at any point in the cycle.
🌺 Hawaiʻi Island Tip — Storage in the Tropics
Neptune's Harvest is cold-processed organic liquid — it will ferment and expand in Maui's heat if stored in a hot garage or shed. Keep bottles in a cool, dark location (interior closet, under the house). If the bottle bloats or the cap pops when you open it, vent it slowly — the product is still usable. Refrigerate after opening if you won't use it within a month. The fish-based products especially attract ants and fruit flies — keep caps tight and wipe drips immediately.
📦 Full Neptune's Harvest Product Catalog for Cannabis
Neptune's Harvest offers both liquid concentrates and dry amendments — all sourced from North Atlantic marine products. Here is every Neptune's Harvest product relevant to cannabis, with OMRI certification status clearly marked.
Not OMRI Listed: Tomato & Veg (2-4-2), Rose & Flowering (2-6-4), Liquid Crab & Lobster Shell (2-0-2). These contain additional ingredients (molasses, yucca extract, humic acids, liquid calcium, biological microbes) that may not meet strict OMRI criteria — but they are still made from natural and organic ingredients. For growers who require certified organic compliance, stick to the OMRI-listed products.
🟢 Liquid Fertilizers — The Core Lineup
Hydrolyzed Fish Fertilizer ✓ OMRI LISTED
2 – 4 – 1
The foundation of the Neptune's Harvest system. Cold-processed fish hydrolysate (not emulsion) — retains proteins, oils, and heat-sensitive nutrients that emulsions destroy. Already-chelated nitrogen for immediate plant uptake. Feeds soil biology aggressively. No unpleasant odor compared to fish emulsions. Use throughout veg and early flower.
Fish & Seaweed Blend ✓ OMRI LISTED
2 – 3 – 1
The best of both worlds — fish hydrolysate blended with Ascophyllum nodosum seaweed. Combines the NPK and microbial feeding of fish with the cytokinins, auxins, and 60+ trace minerals of seaweed. Builds natural sugars (Brix) in plants. University-tested to outperform synthetic 20-20-20. The most popular Neptune's Harvest product — use as your primary feed throughout the entire cycle.
Seaweed Plant Food ✓ OMRI LISTED
0 – 0 – 1
Pure liquid Ascophyllum nodosum seaweed from the North Atlantic. Minimal NPK but packed with natural plant growth hormones, amino acids, and trace minerals. Use in alternate feedings with Fish Fertilizer for a complete program. Excellent as a foliar spray — seaweed absorbs through leaf tissue faster than roots. Increases stress tolerance (heat, drought, transplant shock).
Tomato & Veg Fertilizer NOT OMRI LISTED
2 – 4 – 2
Uniquely formulated for plants with intense growth or vegging stages. Made from fresh fish, seaweed, molasses, yucca extract, and humic acids. The higher potassium (2) vs standard Fish (1) supports stronger stems and improved nutrient transport. Increased stalk/stem mass leads to higher yields. The yucca extract acts as a natural wetting agent, improving root-zone absorption.
Rose & Flowering Formula NOT OMRI LISTED
2 – 6 – 4
The bloom-phase powerhouse. High phosphorus (6) and potassium (4) specifically formulated for flowering plants. Made from fish, seaweed, molasses, humic acids, yucca extract, biological microbes, and liquid calcium. Increases volume and density of buds. Raises Brix (natural sugars) which improves pest resistance. Apply every 2 weeks during flower alongside Tomato & Veg for a balanced bloom feed.
Liquid Crab & Lobster Shell NOT OMRI LISTED
2 – 0 – 2
Liquid chitin delivery system. High in calcium and chitin — chitin triggers beneficial bacteria growth that attacks fungal pathogens and nematode eggs. The liquid form makes calcium and chitin immediately available (vs dry crab shell which takes weeks). Use as a soil drench to boost disease resistance and calcium uptake.
🟡 Dry Amendments — Soil Building
Crab & Lobster Shell ✓ OMRI LISTED
5 – 3 – 0
Dry ground crab and lobster shell — an exceptional source of calcium (17–23%), magnesium (1.3%), and chitin. The chitin promotes chitin-eating bacteria that create a hostile environment for fungal pathogens and root-knot nematodes. Also provides slow-release nitrogen (5%) and phosphorus (3%). Mix into soil at prep or top-dress. Pairs powerfully with Kelp Meal.
Kelp Meal ✓ OMRI LISTED
1 – 0 – 2
Ascophyllum nodosum from the North Atlantic, dried and ground. Contains minerals, carbohydrates, amino acids, alginic acid (27%), and natural growth hormones. Adds organic matter, retains soil moisture, enhances root growth. 66% organic matter content. Mix into soil at prep, incorporate into potting mixes, or top-dress. The dry companion to Liquid Seaweed.
🟣 BioNatural Blooming Blossoms — Biologicals
Bioplin ✓ OMRI LISTED
Biological Inoculant
A biological plant growth promoter used by commercial farmers. Contains beneficial microorganisms that colonize the root zone and enhance nutrient cycling. Promotes healthy root development and overall plant vigor. Apply as a soil drench during transplant and throughout the cycle.
NutriTech ✓ OMRI LISTED
Phosphate Releaser
A biological product whose primary function is to release bound phosphate in the soil, making it plant-available. Many soils have abundant phosphorus that's locked up in insoluble forms — NutriTech's microorganisms convert it. Excellent companion to dry phosphorus amendments like bone meal that need microbial breakdown.
NutriFoliar ✓ OMRI LISTED
Foliar Biological
A foliar-applied biological product that releases phosphate through leaf tissue absorption. Complements NutriTech's soil-based approach with above-ground delivery. Apply as a foliar spray during early flower when phosphorus demand spikes and root uptake alone may not keep pace.
🪶 Kānehiwa's Words
"The sea provides what the mountain cannot. Seaweed carries the minerals of the deep ocean; fish carries the amino acids of life itself. When you feed the soil with the gifts of the sea, you complete the circle — mountain to ocean, root to sky." — Kānehiwa
This guide is provided for educational purposes only. Neptune's Harvest is a registered trademark — this schedule is community-developed and not officially endorsed by Neptune's Harvest. Always research local laws and regulations before cultivating.
