Our Lava Rock

Our 3/8" Minus Red Lava Rock and Black Lava Rock
is All Natural and Environmentally Safe
Horticultural Obsidian Granules

A Brief History

A unique product that started life in the depths of the earth thousands of years ago...

This specially prepared potting and soil conditioner is mined from an extinct volcano near Fillmore, in central Utah. Much like the Hawaiian Islands formed in the Pacific, the volcano rose out of pre-historic Lake Bonneville over 20,000 years ago when the lake covered much of present day Utah, Nevada, Idaho and parts of California. The ancient lava flow was pure obsidian and is still visible. It traveled for miles in all directions. Geothermal zones and ice caves, indicative of volcanic activity, can still be found around the volcano.

This unique foamed obsidian is mined in the outer slopes of the volcano. During the volcanic eruption, molten lava, from deep inside the Earth, spewed upward, absorbing volcanic gases as it rose and gradually cooling as it shot from the mouth of the volcano. The gaseous, quick cooling lava near the crater formed today's bubbly, lightweight, multi-colored obsidian which is honey-combed throughout.

The different temperatures at which the molten lava rose and cooled resulted in this unique material's many different colors, which are often found side by side.

Heavier obsidian chunks, originating from deep inside the throat of the volcano, shot upward during the eruption during the eruption and can also be found miles away.

When fissures occurred in the walls of the volcano, molten obsidian flowed like glass and hardened into black masses.

All natural 3/8" minus Red Lava Rock and Black Lava Rock for potting and soil conditioning is a unique product, believed to be found in only one location in the United States in such quantity. It is a totally inert, naturally foamed producted, especially used in lightweight potting and soil conditioner. Its foamed porous obsidian cannont impart any harmful chemicals to you or the environment.

Use 3/8" minus Red Lava Rock and Black Lava Rock in place of Perlite and Vermiculite...

PERLITE is produced by applying 1800 degrees fahrenheit to heat ordinary Lava or Pumice Rock which expands it. Although it holds moisture it also looses it's quality under use, and can leave unwanted residue. It is used mainly for aeration of soils rather than moisture holding. pH range is normally 7 to 7.5. It is often used instead of washed sand to aerate. The excess floride is sometimes a problem, as is the dust.

VERMICULITE is prodced by applying 1800 degrees fahrenheit to Mica to expand it. It has been found to be of value in the first time use of potting soils. Under high watering it tends to float. Unfortunately for second and third time use, it tends to break down into a gooey state, which is negative to plant growth. pH range is normally 6.5 to 7.2.

3/8" minus Red Lava Rock and Black Lava Rock granules are naturally plant friendly. These particles of foamed obsidian will melt into black glass when subject to 1800 degrees fahrenheit heat. The granules have remained in their present state for over 20,000 years. Therefore, you can rely on their indestructible nature, performing their tasks controlling moisture and aerating soil without leaching or breakdown. This is why many new types of commercial potting formulas now incorporate lava rock granules in their mixes. You can use this product with confidence.

Lava Rock granules will not, by themselves, support fungus, disease or harmful plant predators, pH is the same as for glass, which is to say neutral.

Most potting soils are formulted to be in the pH range 5.2 to 6.2, slightly on the acid side, with 7.2 being neutral.

For Potting and Garden Use


Use 3/8" minus black lava rock or red lava rock to store bulbs. Being inert it is a natural pH stabilizer. Blend with peat moss for soil-less potting mix. As an aerator it is second to none and can be used in place of Vermiculite, Perlite and Pumice. Mix when planting to loosen and aerate heavy clay soil. It allows roots to breat and prevents the build-up of anaerobic bacteria. IT IS AN EXCELLENT POTTING MEDIA ADDITIVE.

Blending Your Own Potting Soil


For a clean soil-less mix, here are three formulas excellent for virtually all potted plants.

FORMULA I:
for fibrous rooted plants like African Violets and Gloxinias,
  • blend 1 part Sphagnum Peat Moss
  • 2 parts 3/8" minus lava rock granules

    FORMULA II:
    for Succulents and Cactus,
  • blend 1 part Sphagnum Peat Moss
  • 3 parts 3/8" minus lava rock granules

    FORMULA III: for Philodendron, Fern, Begonias and plants requiring soil that holds considerable parts moisture,
  • blend 1 part Sphagnum Peat Moss
  • 1 part 3/8" minus lava rock granules

    For All Formulas

    To each gallon of FORMULA I, II, or III mix, add 1 and 1/2 level tablespoons of Dolomite Lime. Mix thoroughly. Apply Lime every other month at 1 Tablespoon of 12 inces of potted plant.

    For established plants requiring higher pH, use up to double the the amount non-hydrated ground limestone per gallon of mix.

    For Loosening Heavy or Clay Garden Soils

    Apply 1 to 2 inches of lava rock granules to surface to be treated in your garden, and mix thoroughly by spading or rototilling. It will help retain soil moisture and nutrients and aerate the soil, reducing potential anaerobic conditions.

    For Root Cuttings

    Use a mixture of 2 parts lava rock granules and 1 part sphagnum Peat Moss. Wet thoroughly. Insert prepared cuttings to a depth of 1 1/2 to 2 inches. Place large clear plastic bag over container to form a small greenhouse. Removef the bag when the cuttings are rooted. Do not place the plastic covered container in direct sunlight.

    For Starting Seeds

    Mix equal volumnes of Sphagnum Peat Moss and lava rock granules and 1 tablespoon Dolomite Lime per gallon of mix, wet thoroughly and mix. Place in shallow container to be seeded compress lightly, water again and sow seeds in rows. Don't cover small seeds; cover large seeds lightly. Place container in clear plastic bag, removing as soon as seedling leaves appear. Keep plants watered. Do not place plastic covered container in direct sunlight.

    To Store Bulbs

    Use a deep rodent-proof container. Alternate 1 inch of lava rock granules with a lay of bulbs to a 12 inch depth. Cover with 1/2 inch wire mesh. Do not water bulbs in storage. Place container in a cool place where temperature does NOT fall below freezing. Lava rock granules protect the bulbs from drying and severe temperatures changes because of its highly beneficial insulating qualities.

    The use of lava rock granules to existing formulations can be beneficial where there is a need for added opening up or aeration of the mix. This is especially beneficial for repotting existing plants.


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