15 oz Large Pumice for Bonsai Soil, 3/8–1/4 Inch Volcanic Rock, Succulent and Cactus Soil Amendment, Natural Oregon Pumice

15 Ounce Bag of Large Pumice – 3/8" to 1/4" – Natural Oregon Volcanic Pumice

Looking for a larger, clean-screened pumice for your custom soil mixes? Our 3/8" to 1/4" pumice is hand screened to provide a larger particle size for bonsai, cactus, succulents, and specialty potting mixes.

Our pumice is a natural volcanic product mined in the Southern Cascade Mountains of Oregon. You receive clean pumice without rocks, roots, or other debris.

Product Details

• Quantity: One 15-ounce bag

• Particle size: Approximately 3/8" to 1/4"

• Material: Natural volcanic pumice

• Source: Southern Cascade Mountains of Oregon

• Processing: Hand screened

• Packaging: Hand packed in a bag with a reusable tie for convenient storage

Known as the "rock that floats," pumice contains many tiny gaps and air pockets. Its larger particle size makes it useful for creating customized soil blends.

Suggested Soil Mix Ratios

Use pumice to adjust the composition of your growing media:

• General horticultural use: Mix approximately 15% pumice into soil for Japanese maples, raised beds, and containers.

• Water-sensitive plants: Use approximately 30% pumice for Gunnera, Giant Sequoia, Daphne, Monkey Puzzle trees, Franklin trees, and similar plants.

• Cactus and succulents: Use 60–80% pumice with 20–40% organic matter.

• Bonsai soil: Mix approximately 33% pumice, 33% coarse compost or bark, and 33% lava or very coarse sand.

These are suggested mixing ratios; adjust your blend to suit the needs of your plants and growing conditions.

Available Package Sizes

This pumice is also available in:

• 15 ounces

• 10 cups

• 5 quarts

• 3 gallons

• 6 gallons

Shipping Information

• 15-ounce bag: Ships First-Class Mail.

• Larger package sizes have different shipping methods.

Samples Available

If you would like to check the pumice particle size before purchasing a larger quantity, samples are available for the cost of shipping.

Please note:

• The sample is not large enough for a project.

• If you later order 6 gallons or more, your sample shipping cost will be reimbursed.

• Leave a message in Special Instructions to Seller with your sample order details when placing your qualifying larger order.

Handling and Storage

Pumice is hand packed in a bag with a reusable tie so you can conveniently store any unused material.

If the pumice dries before use, moisten it to help prevent dust from forming. Dust from rock and potting soil products should not be inhaled and may irritate sensitive lungs.

Thank you for supporting our specialty growing media!