7 Best Soil Amendments & Fertilizers for Your Organic Garden

If you’ve read anything about my gardening philosophy, you know I’m not a fan of using a lot of fertilizers – but some of them actually are great, beneficial products.  And at times our plants just need a boost, especially in new gardens that have low soil food web activity!  I’ve grown countless gardens and have tried the whole gamut of various organic gardening products.  Here I’ve listed below my top 7 favorite soil amendments and fertilizers that are essential for your organic garden.  (Affiliate links present in this post, all products recommended at my own discretion)


1 & 2.  Kelp Meal & Alfalfa Meal – Granulated Organic Fertilizers to Add During Soil Prep


During soil prep, the combination of organic Kelp Meal and Alfalfa Meal, along with good quality compost, will fulfill the majority of macro- and trace minerals needed during soil prep.  Alfalfa Meal, derived from alfalfa grass that is commonly used as a cover crop to break up heavy clay soils, will add nitrogen, calcium and trace minerals to your soil.  Kelp Meal, derived from seaweed, will provide high amounts of potassium and 60 other trace minerals for your soil.  Use these in combination.  For a tutorial on how to add them to your soil, watch this video.

For information on how to prepare your soil, visit my post on building soil fertility.


  1. 3.  MYKOS – Mycorrhizal Fungi Inoculant to Use During Planting

Mykos is a mycorrhizal fungi inoculant – that fungi being the number one key player in providing nutrients directly to the roots of our plants!  This is a product I never go without when initially planting a garden.  A 2.2-lb bag is good for a huge garden, but a smaller amount would be sufficient for a smaller garden.  I choose to use this only on long-term plants that will spend their entire life cycle in the garden (tomatoes, peppers, eggplant, squash, etc).  The presence of mycorrhizal fungi in your soil is absolutely essential for proper nutrient exchange, so I highly recommend using this product at least during your first year.


4.  Neptune’s Harvest Fish & Seaweed Blend 2-3-1 – Liquid Fertilizer to Use When Planting and Fertilizing Throughout the Growing Season

This stuff is simply amazing, and one of the only fertilizers you will need, throughout the growing season.  It provides all the macro- and micronutrients our plants need, and its liquid form makes it much easier for our plants to intake the nutrients.   I apply this to gardens once every 2 weeks on heavy feeding vegetables (tomatoes, peppers, eggplant, squash, cucumbers, etc) and perennial fruits, by either drenching at the roots or as a foliar feeding spray.  The dilution rate is 1 tablespoon per 1 gallon of water, so this bottle will take you into next season!


5.  Organic Blackstrap Molasses – To Use Throughout the Growing Season

Soil microbes, especially bacteria, need sugar to eat and thrive – I like using molasses as a spray mixed with Neptune’s Harvest Fish & Seaweed Blend.  Only use a tiny amount – 1 teaspoon per gallon – otherwise your bacterial colonies will multiply at crazy rates and gobble up their entire food source at once.  I like to use this spray one time per month, fully spraying the soil surface and foliage of all the plants.  Your molasses should be organic and unsulfered.


6 & 7.  Vermicastings & Live Red Wiggler Worms – To Add During the Season



Vermicastings, or worm turds, are a completely natural, heaven-sent fertilizer – and the presence of earthworms is the greatest gift we can give our gardens!  Annual vegetables prefer soils that are dominated by bacteria purely because of the way they prefer their nitrogen (in the form of nitrate rather than ammonium), and earthworms naturally have bacteria present in their guts.  Worms provide the ultimate beneficial bacteria environment for our edibles!  Not only that, but worm castings have 50% more organic matter than regular old soil, and 5 times the amount of nitrogen.  Worms also help shred leaves and other organic materials in the soil to help break it down for soil microbes to feast on them – and they create an amazing network of tunnels through the soil, allowing pockets of air and moisture to encourage root growth.  Seriously – Get yourself some worms!  Add a bag of castings as a side dressing for your plants, and sprinkle the worms evenly around your garden beds – they will multiply soon enough.

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