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

10 Cups of Large Pumice – 3/8" to 1/4" – Natural Oregon Volcanic Pumice

Our larger 3/8" to 1/4" pumice is ideal for gardeners and growers looking for clean, hand-screened volcanic pumice for custom soil blends. Mined in the Southern Cascade Mountains of Oregon, this natural pumice contains no rocks, roots, or other debris.

Known as the "rock that floats," pumice contains many tiny gaps and air pockets. Its larger particle size makes it a useful ingredient for bonsai soil, cactus and succulent mixes, and specialty growing media.

Product Details

• Quantity: 10 cups of pumice

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

• Material: Natural volcanic pumice

• Source: Southern Cascade Mountains of Oregon

• Processing: Hand screened

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

Container Fill Information

One 10-cup box will fill approximately 1⅓ trade-gallon containers.

Suggested Soil Mix Ratios

• 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 your plants and growing conditions.

Other Available Package Sizes

• 15 ounces

• 10 cups

• 5 quarts

• 3 gallons

• 6 gallons

Shipping Information

• 10-cup quantity: Ships USPS Priority Mail.

• 15-ounce quantities ship First-Class Mail.

• 5-quart quantities ship Priority Mail.

• 3- and 6-gallon quantities ship UPS.

Samples Available

Want to check the particle size before purchasing a larger quantity? Samples are available for the cost of shipping.

• 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 when placing your qualifying larger order so we can refund the sample shipping cost.

Handling and Storage

Pumice is hand packed in a bag with a reusable tie for easy storage after opening.

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!