The Super Soil Conditioner
is used throughout a component of soiless growing mixes where it provides aeration and optimum moisture retention for superior plant growth. For rooting cuttings, 100% perlite is used. Studies have shown that outstanding yields are achieved with perlite hydroponic systems. Other benefits of horticultural perlite are its neutral pH and the fact that it is sterile and weed-free. In addition, its lightweight makes it ideal for use in container growing. Other horticultural applications for perlite are as a carrier for fertilizer, herbicides and pesticides and for palletizing seed. Horticultural perlite is as useful to the home gardener as it is to the commercial grower. It is used with equal success in greenhouse growing, landscaping applications and in the home in houseplants.
Three Types of Horticultural Perlite Products
Since perlite is produced in different grades, particle size can be tailored to suit the requirement :
Horti-Perl (Coarse Grade)
Provides maximum aeration and holds 197 to 282 liters of water per cubic meter after 24 hours free drainage (at field or container capacity, where all free water is drained, without suction).
Super Grow (Medium Grade)
Provides considerable aeration and holds 334 to 400 liters of water per cubic meter after 24 hours free drainage.
Easy Grow (Fine Grade)
Provides less aeration and holds 400 to 467 liters of water per cubic meter after 24 hours free drainage.
Enlarged Root Section
This drawing shows a root section in a well-prepared soil . Soil structure has been modified so that nearly half the mass is taken up by large pore spaces holding air. and small pore spaces holding water. A thin film of water is held on the surface of each particle of horticulture perlite. Air, water, and nutrients move from soil through root hair and are transported to the stem and leaves.
Typical use is 20% to 100% coarse Horti-Perl, Supergrow or Easy grow, depending on cutting type, i.e. softwood cuttings propagation generally utilize 40% to 80% Horti-Perl (with peat or coir comprising the balance) whereas hardwood cutting propagation generally uses 70% to 100% Horti-Perl.
Typical use is 20% to 100% using any grade of perlite (generally the smaller the seed, the finer grade of perlite to be used.) Fort Bonifacio Nursery, by switching to perlite coir dust media from sand coir dust media, eliminates the disease losses although they continue to treat the seed with fungistat.
Keeps the surface dry enough to encourage positive geotropism (root growing down), minimize topsoil bridging between plug cells, reflects light up around the seedling (promoting stockier seedlings) and reduces disease relative to some other seed mulches.
Pony pack /cell packs / four inch container use 20% - 55% perlite by volume, with the balance being peat or coir dust or fiber or redwood fiber or composed fir or pine bark. Sand should be avoided because of its disease drawbacks and its silt and clay content that gum up the lower portion of the pot profile.
Including Mums, Poinsettia, Gloxinia, etc., Use coarse Horti-Perl at 40% - 60% by volume
Uses Horti-Perl or Supergrow at 20% - 50% with peat or coir fiber. Air pruning often takes place at the bottom of the tray by tray design.
Orchids-Perlite used to good advantage in the transfer of orchids from flask to community pot stage, and for Phaelonopsis / Cymbidium growing on posts at 10% to 100% (commonly approximately 20% to 50%). Likewise, for Spathiphyllum for Bromeliad and Malesian Rhododendrons.
Horti-Perl used at 30% - 80% by volume for citrus seedling understock, mango and avacado seed understock (and special stem etiolation above nurse graft).
All grades of perlite at 10% - 100%. Above ground planters where perlite improves drainage and at the same time water retention (to mitigate high evapo-transpiration rates which prevail in these conditions) at 1/4 - 1/3 the weight of the conventional media, e.g. wet sandy loam weights from 1920 to 2240kg. per cubic meters vs. a 50 - 50 perlite/peat mix at 560 kg./cubic meter. This reduction in dead load not only reduces structural requirements but also facilitates container movement.
Perlite used at 10% - 25% by volume, in new construction, to great advantage to improve air-water dynamics and thus rooting and tillering. Medium grade Supergrow , particularly, maintains dimensional stability of the top mix and mitigates against the tendency of sand to declassify and stratify over time. It allows the designed perched layer to function properly long term, thereby optimizing water reservoir condition in the top mix, allowing excess water to pulse down and drain rapidly under accumulated head pressure. Existing greens also benefit from perlite renovation both in core plug application and as a surface insulator to minimize burn.
Easygrow (fine) is ideal for keeping soil open and for retaining extra water (specially in sandy loam). All grades of perlite will reduce surface ponding and crusting to allow quick water absorption, while still retaining water. Best results are obtained at 15% - 30%, by volume, rototilled in to a depth of 6-8 inches. This treatment can be renewed every 1 to 4 years.
Horti-Perl (coarse) or supergrow(medium) grade perlite (with some particle size gradient) can be used to maintain capillary action. Perlite outperforms rockwool and other hydroponic media, with less salt buildup and none of the landfill disposal problems attendant with rockwool use. Also enjoys an advantage where electrical brownouts occur periodically, since the inherent capillary action of the perlite will continue to wick up water and water soluble nutrients without the need of power. Alkaline drift, basic residue fertilizers, etc. in hydroponics, can be balanced with proper ration of nitrate, ammonia, (e.g.7:1) in warm humid climates.
Export Media
All perlite grades can be used at 30% - 100% by volume as an export media to eliminate insect / nematode and disease contamination and ensure compliance with requirements of importing countries. Fort Bonifacio Nursery in the Philippines will use this media to grow and ship smaller plants (up to 100 ml) while larger plants will be conventionally grown, with the roots then washed and placed in the perlite mix for shipping.
Selected Outdoor Species
Horti-Perl (Coarse), Supergrow (Medium) and Easygrow (Fine) perlite (the latter for extra water retention) used at 15% - 40% by volume. Coarse perlite used to grow selected plants such as Azalea, Rhododendron, Camellia, Dwarf Excallonia; selected ferns, upright junifers, Decidous Magnolia, Orchids and Bromeliads.
Advantages of Using Horticultural Perlite
* Horticultural Perlite is the ideal soil conditioner
* Aerates and Drains soil
* Increases water holding capacity, nutrients and fertilizer retention
* Decreases soil crusting and compacting
* Insulates-Minimizes temperature fluctuation
Advantages of Using Horticultural Perlite
- Horticultural Perlite is the ideal soil conditioner
- Aerates and Drains soil
- Increases water holding capacity, nutrients and fertilizer retention
- Decreases soil crusting and compacting
- Insulates-Minimizes temperature fluctuation
- A naturally occuring mineral
- Lighweight and easy to handle
- Sterile, disease, and weed-free
- Neutral with a pH of 6.5 to 7.5
- Available in various gradiations
- Permanent and will not rot or dissolve
- White color - assures uniform mixing
- Improves aeration and drainage
- Improves moisture and water soluble nutrient retention
- Lightweight, so easy and economical to handle in growing and shipping
- Sterile: Free of weed seeds, disease and insect
- Inorganic, heat / chemical stable and does not deteriorate
- Insulator-reduces soil temperature fluctuations
- Clean, odorless and safe to handle
- White color - assures uniform mixing
