Pumice 25 Litres 

Pumice is a light siliceous vesicular volcanic rock that is suitable for use in horticulture and hydroponics. Its porosity provides air spaces that maintain aerobic conditions around the roots while water is contained within the pores. Surface tension around the outside of the pumice particles increases water-holding capacity of the growing medium.  Pumice is a popular growing medium for Cacti, Succulents, Bonsai, Orchids and many other plants.

Our pumice is mined from a land-based resource, within 50kms of Lake Taupo in the North Island of New Zealand, and it is characterized by its relative hardness and lightweight in comparison to competing aggregates. The washing and screening of our pumice particularly for horticultural applications means that no ‘fine’ particles are included. Unwashed pumice can cause ‘concreting’ and higher water holding capacity than required, consequently affecting root development.

This hardness and porosity allows free drainage lowering the risk of root-rot diseases.

Pumice grades:

• 1-2mm (New)
• 1-7mm
• 4-20mm
• 7-20mm

What is Pumice?

Pumice is a lightweight foamy volcanic rock. The bubbles in the matrix are brought about by rapid cooling and depressurisation when the lava is ejected from the volcano. Pumice provides an ideal balance between water-holding capacity and air-filled porosity, allowing aerobic conditions around roots while containing an adequate supply of water. The high surface area is ideal for root hairs to penetrate and gain good anchorage for stable plants. Our pumice is mined in the beautiful North Island of New Zealand, from a site near Lake Taupo of New Zealand, and it is characterized by its relative hardness and lightweight in comparison to competing aggregates.

Usage:

Use pumice for Orchid mixes, grades 7-20 is particularly well suited for orchid cultivation providing the balance of air and water combined with long life. Pumice will not rot or break down, it is less likely to wash out of the pot. For propagation use the smaller grade 1-2 and 1-7. Hardwood cuttings can be stuck in 100% pumice. The variation in particle sizes allows excellent basal contact for supply of water yet the porosity maintains aerobic conditions around the newly formed roots. Slow rooting species such as Conifers, Maples and Camelias are particularly well suited to propagation in pumice. Cacti and Succulents need to open and well-drained potting mix, pumice is ideal for this purpose. Mix 30% pumice with your preferred organic substrates. Pumice has been used extensively for green roof mixes where substrates need to be long-lasting, lightweight, free draining and moisture retentive.

Ideal For:

• Orchids.
• Cacti and Succulents.
• Bonzai.
• Propagation.
• Green Roofs.
• Long Life Potting Mixes.

Properties:

• Light Weight.
• Up to 90% Porosity.
• Inert.
• Clean.
• High Capillary Action.
• Low Cation Exchange Rate.
• Washed and Screened to Remove Fine Particles.

GRADE      ADMIX                                                                          TYPE                                                               EXAMPLES

1-2mm     100% Pumice                                                                 Hardwood cuttings. Slow rooters                       Conifers

1-2mm     50% Pumice / 50% Peatmoss                                          Softwood cuttings.                                           Murrayas, Viburnum

1-7mm     60% Pumice / 20% Coarse Sand / 20% Peatmoss             Cacti / Succulents                                            Echiveras

1-7mm     100% Pumice                                                                 Hardwood cuttings. Slow rooters                       Maples, Camellias

1-7mm     40% Pumice / 30% Medium Bark / 30% Fine Bark             Seedling mix, Pup mix.                                    Cymbidiums, Cycads

1-7mm     40% Pumice / 30% Coarse Sand / 30% Peatmoss             Stem cuttings                                                  Frangipanni, Cordyline

7-20mm   40% Pumice / 30% Coarse Bark / 30% Medium Bark         Orchids                                                           Cymbidiums

Frequently Asked Questions

Q. Which pumice grade is best for growing Succulents?

A. According to the manufacturer, they suggest using mostly 1-4mm with a little 4-10 mixed though. The pumice should also be mixed with 50 to 75% of fine to medium organic matter like compost and garden soil.

Q. What is the PH of this pumice?

A. According to the manufacturer "The pH of Pumice is typically pH 6.7 to 6.9"

Q. What is the country of origin for this pumice?

A. It's from New Zealand.

Q. How much does a 25L bag weigh?

A. The weight of this item can vary significantly due to moisture content or the weight of pumice rock. We tested some bags at around 21kg but again this can vary.