Organic Soil Mixes and
Soilless Hydroponic Mixes

For different gardening styles and situations there are different soil mixes that are appropriate. Below are a few mixes that I use myself for different occasions, and an explanation of how you can use each in your gardening strategy. The soil recipes below should do well for most plants, but are not for acid loving plants.

Quick Tips

A large container, such as a cheap plastic storage tote or a kiddie pool, comes in handy for making soil mixes. It is easier to mix ingredients evenly when everything is dry. It would be a good idea to wear a dust mask whenever you are mixing soil. Another option is to add all the ingredients to a garbage bag, close it, and mix your soil up a couple of containers at a time this way. Finally, a hand-pump spray bottle full of water helps to knock the dust out of the air if it does get too dusty.

A Good Seed Starting Mix

worm castings

You want a seed starting mix to retain moisture, yet be well draining. There is little need to add very many nutrients at this point. You can purchase commercial potting soil for this, or you can make up your own soil mix.

For starting my own seeds, I use equal parts vermiculite, perlite, and sphagnum peat. I than add 10 percent worm castings. You should add 1 teaspoon of lime for each gallon of soil and mix well. The nitrogen in the worm castings is gentle to the young sprouts, and it is in a form the new plants can use immediately.

To help things out, I wet this soil down with water, first making sure to add 10 ml/gallon Thrive Alive B1 and 10 ml/gallon Maxicrop liquid seaweed. Make sure not to make the mix too wet...the roots need air. The mix is just wet enough when you squeeze a handful and only a few drops come out.

Soil Mixes You Eventually Feed

If you are unsure of the exact needs of your plants, than this is a good soil mix to begin with. It is also good if you are transplanting shortly before flowering, but want to feed your plants through watering once flowering begins. It contains enough organic fertilizers to feed your plants for about two weeks, than you can begin adding a little fertilizer at a time as you water.

bat guano Start with equal parts vermiculite, perlite, and sphagnum peat. To this, add 20-25 percent worm castings. Never use more than 25 percent worm castings in any of your soil mixes.

For every gallon of soil add 1 teaspoon of lime and mix everything together well. For each gallon of soil, add 1 tablespoon of bat guano and 1 1/2 tablespoons of kelp meal and mix well. Here I have shown a high phosphorus guano, but if you are still in the vegetative stage, use a high nitrogen guano (like Mexican bat guano). After about two weeks of growth, begin watering with a 50 percent strength nutrient solution.

Keep a close eye on your plants to see if they want more, or need less. As you gain experience and learn the different fertilizer and soil additives, you will be able to mix up your own favorite custom soil mix.

Soil Mixes You Don't
Have to Feed

If you hate mixing up fertilizer each time you water, than this strategy might be for you. Start your seeds in a regular seed starting mix. Than, each time your plant is ready for a bigger container, transplant it into this fertile organic soil mix. If you time it so your last transplant occurs the same time you begin flowering, you should only ever have to give your plants plain water (although I recommend you add Thrive Alive and Maxicrop to your water also).

foxfarm soil

Begin this soil mix by adding one bag each of Foxfarm Original, Foxfarm Ocean Forest, and Foxfarm Light Warrior. To this mix, add 1 level cup of Foxfarm Peace of Mind 5-8-4 and mix well. I usually begin my plants in the smallest dixie cups I can find, in my seed starting mix. After that, I transplant into a 6 inch container of this mix. Two or three weeks later, I transplant into a 12 inch container. Finally, right as I switch to flowering, I make my final transplant to the next size container (usually a three gallon one). Most of the nutrients are used up by the time I begin flushing them, so it works out well.

Soilless Mixes for Hydroponics

Sometimes people use soilless mixes in hydroponics. This is especially true for the hand watering method. The idea is to make a mixture that holds moisture as long as regular organic soil mixes would. This is accomplished by using vermiculite, sphagnum peat, or coconut coir, all of which retain water. A good place to start is to use equal parts of each.

Another example is the reservoir method. This method is well suited for the use of lava chips as a medium, but a mix of 1 part vermiculite to 5 parts expanded clay pellets works as well. The same mix should work well in other systems, like a drip system, although I have never tried this myself.

A soilless mix heavy in materials that suck up water is perfect for the wick system. An equal mix of perlite and vermiculite works well. A mix of perlite and coconut coir should work equally as well.

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Check out the Organic Hydroponics page

Learn How to Feed Your Plants with Hydroponic Nutrients