Improve Your Garden Soil with PUMICE
The Professional Grower's secret

  • Loosens heavy clay soil - lets air and water penetrate
  • Holds moisture in sandy & clay soils - reduces watering by 35%
  • Will not float to the top of the soil
  • Will not deteriorate, compact or blow or float away
  • Neutral PH

HORT-I-LITE
Commercial growers have searched continuously for a growing medium that would solve a multitude of problems connected with growing.
In the novel, Hawaii, James A. Mitchener, describes vividly the formation of the island from lava or pumice into a tropical paradise. The fact that tropical islands consisting principally of lava rock and pumice could produce such luxuriant growth developed an extreme interest in pumice research. It showed that pumice was, indeed an ancient growing medium. Soils of volcanic origin that have been enriched through centuries of decaying vegetation, dust and animal life have been provided with sufficient nutrients to grow plants in abundance. In the rain forests in the state of Washington, it requires nearly 25 years to grow timber of sufficient size for cutting, yet, in a section of New Zealand which is called, "Pumice Land," a crop of trees matures in approximately half of that time.

WHAT IS HORT-I-LITE PUMICE
In the California desert about fifty miles West of Death Valley, in the barren country that lies between the Panamint Mountains and the High Sierras, men and machines cut away tons of a fantastic crude material that has been used since before the days of ancient Rome in industry and agriculture. This material is called Pumice. A careful selection of the crude pumice, followed by proper screening and crushing provides the users of HORT-T-LITE brand pumice with a product near white in color, low in apparent bulk density and consistent gradiations and special screened size.

Unfortunately, the general name, "pumice," is applied to a variety of materials of different purity and differing chemical makeup. This particular deposit, by the workings of nature over a period of time, is of a uniformity and purity almost unmatched elsewhere in the world.

HORT-I-LITE is a fragmental volcanic rock having a porous fabric of 70 percent. It is a natural compound of volcanic origin. The microstructure of pumice is a framework of glass pervaded by an extensive and intricate network of cavities varing greatly in size and shape, and are largely in a material of relatively low bulk density without serious sacrifice of strength. It is composed mainly of complex silicates of aluminum, sodium, potassium, calcium, magnesium and iron.

HORT-I-LITE is about as hard as Feldspar, but is slightly softer than Quartz. It is more friable than other types of volcanic rock. When crushed it fractures into angular shapes. The function of pumice in soils is to render the soil more porous, improve aeration and drainage.

HORT-I-LITE has been used successfully as a soil amendment in rooting, propagation, potting, greenhouse tables, fiats, mulching, rowcrops, citrus, pasturage, hydroponics, germination of seedlings, orchid growing, land and turf management.

Briefly, HORT-I-LITE has the following characteristics which make it an ideal horticultural medium:

  • Excellent aeration
  • Good drainage
  • Neutral PH
  • Does not break down, (can be used over and over again).
  • Does not rot
  • No shrinking or compacting in aging
  • Easy to control nutrients
  • Not a host to fungi, nematodes, insects, etc.
  • Easily leached
  • No offensive odors

"HORT-I-LITE PUMICE FOR HORTICULTURAL GROWING MEDIA"

The roots of plants are living organisms requiring a continual supply of oxygen, the introduction of air into the soil even though it is wet is very important. Likewise, roots are constantly releasing carbon dioxide, (via respiration), which must be removed from the root zone. Plants require that these gases be supplied or exhausted via soilpores. Thus, a good soil must be porous to permit the exchange of gases while also adequately retaining water to meet the needs of the plant. Additionally, the plant must obtain more than a dozen elements from the soil for its growth.

Poor growth may result from poor aeration, lack of water, or nutritional disorders. Poor aeration also often contributes to disease attack by water molds and other pathogens. HORT-I-LITE, because of its unique internal porosity and its relatively coarse size, (reference is here made to the large pores created between pumice particles) will improve aeration in soils without sacrificing water holding characteristics. The entire volume of air in the root zone of a well aerated soil must be replaced several times a day. Once HORT-I-LITE is in the soil it is permanent, as it tends neither to sink nor to float out.

HORT-I-LITE has excellent drainage characteristics similar to coarse sand. It is most important that soil has a relatively high air space after drainage. HORT-I-LITE compares very favorably with organic amendments in this respect. Clays are notably low in this property. Leaching of excess soluble salts is no problem with adequate pumice incorporated, when it becomes necessary. Where bark or other wood residuals are employed, it is always desirable to fumigate or steam in order to avoid possible pathogen introduction.

HORT-I-LITE used for propagation or where employed as the sole component of the growing medium, no chemical additives are required. The PH, salinity and nutrient status will quickly become that of the applied water and nutrient solution due to the low buffer capacity of pumice.

Since HORT-I-LITE cannot break down by decay, it gives the grower complete control of his feeding. Therefore, he does not have an excess of certain forms of nitrogen caused by the breakdown or decay and need not worry about having too much available at the wrong time. Since it does not decay, there is no shrinkage and consequently no decay odor. It does not generate heat, so insects and fungi are not encouraged to propagate. The surface of the material is rough so slugs and snails avoid it.

In using HORT-I-LITE as s soil amendment, advantages are obtained with as low as 10 percent pumice and in some fine, (referring to clay), horticultural soil conditioning, as high as 50 percent pumice is used for bedding to improve aeration. Quantities blended into soils ranging from 20 to 50 percent by volume are usually effective.

ROW CROPS
HORT-I-LITE is distributed between the rows and covered; of course, it must be within reach of the roots. In row and field crops, from 15 to 20 percent pumice seems to be sufficient to obtain excellent results. This means that for every 5 or 6 inches of depth of cultivation, 1 inch of pumice should be used.

SOIL MIXES FOR CONTAINERS
Extensive research has shown that foliage plants thrive in an organic type soil which has high aeration and retains moisture well. A mixture of one part HORT-I-LITE to one part peat moss by volume will grow luxurious plants if properly fertilized. Flowering pot plants will grow well in a mix containing one part HORT-I-LITE, one part peat moss, and two parts bark by volume. Starting annuals in flats or pots can be accomplished with success by using the mixture for flowering pot plants.

PROPAGATION MEDIUM
HORT-I-LITE is particularly valuable for propagation, because of its limited water holding and good aeration properties; it will not compact or become soggy. Due to its characteristic of clinging to roots and because of its light weight, roots are not broken when the cuttings are lifted, as often happens when cuttings of carnations, chrysanthemums, poinsettias, geraniums, hydrangeas, etc., are removed from sand mixtures. The material can be used over and over again. Before inserting the cuttings, it is good to make a small "V" trench for the cuttings and then firm them in to keep them upright, if one has a water tight bench, it should be filled until there is a slurry of HORT-I-LITE and water. The cuttings should then be inserted and the water drained off. Cuttings will root well in HORT-I-LITE when intermittent mist system is used for watering.

TROPICAL FOLIAGE PLANTS
For special propagation of tropical foliage plants, a mixture of one part HORT-I-LITE and one part peat moss may be used. For rooting the ornamentals, from Azaleas to Xylosma, HORT-I-LITE can be used mixed with an equal volume of peat moss. For mist propagation HORT-I-LITE should be used alone or with only ¼ part peat moss by volume to take advantage of HORT-I-LITE's excellent drainage characteristics.

SEEDS AND SEEDLINGS
Mixtures of one part HORT-I-LITE to two parts bark of sawdust by volume make for rapid seed germination and seedling growth. This mixture remains loose and friable. In out-of-doors seed beds, the soil can be made more mellow and loose while the tendency to crust is essentially eliminated by adding 1/4 to 1/2 inch of HORT-I-LITE to the surface of the seed bed.

SOIL MULCH
HORT-I-LITE is an effective mulch in shrub and flower beds. It is a type of mulch that has aesthetic as well as practical value in gardening. The soil beneath the mulch stays moist for a longer period and does not compact due to overhead watering. HORT-I-LITE will not breakdown so there is never a replacement problem. A mulch 2 to 3 inches thick effectively minimizes weed problems. HORT-I-LITE can be colored any shade desired by merely soaking it in food color dye which can be purchased at your local food center. It may also be applied by spraying. As a mulch it is also an ideal insulator, it will prevent temperature rise in the root zone, making it possible for continual growth activity even under extremely high temperature conditions, it has been successfully used in Palm Springs to maintain lawns throughout the summer in excellent condition.

LAWN AND TURF MANAGEMENT
In establishing new lawns, it is used in preparing the seed bed, incorporated in the soil and also for mulching the seed. HORT-I-LITE will have no objectionable odor as steer manure has. It will not compete for the nitrogen in the soil as the organic materials, (such as sawdust) when they breakdown. In established turf, it can be used as a top dressing after aerification, especially on golf greens. The heavy traffic and use of machinery causes compaction, the destruction of pore spaces in the soil. Aerification and use of HORT-I-LITE (which does not decompose or pack) will restore the soil structure and make possible better root growth.

PROBLEM SOIL SOLUTIONS
Heavy Clay or Adobe Soils:
Clay or dense soils are so compacted that their structure does not allow outside nutrients and moisture to penetrate to plant roots, thus, leaving the plant deficient. Incorporating 2 cubic feet of HORT-I-LITE to 10 square feet, to a depth of 6 inches by rotatilling, will allow good penetration. This results in about 25% pumice by volume.

Medium Clay or Adobe Soils:
Use 2 cubic feet of HORT-I-LITE to 20 square feet of area, to a depth of 6 inches. This results in about 2096 pumice by volume.

Light Clay, Adobe:
Water holding capacity is reduced by using 3 cubic feet of HORT-I-LITE to 40 square feet to an area, to a depth of 6 inches. This results in approximately 15% pumice by volume.

INTERIOR PLANTS IN PRIVATE HOMES AND PUBLIC BUILDING
To maintain the plant material in the best possible condition for as long a time as possible, it is essential to maintain adequate moisture in the growing medium; and at the same time to have excellent aeration and drainage. A 50-50 mixture of HORT-I-LITE and peat is ideal for this purpose. A light liquid feed monthly will keep the plants growing well.

SOIL MIXES FOR CUT PLOWER PRODUCTION IN BEDS AND BENCHES
HORT-I-LITE increases the porosity of the soil, making possible a much better root growth, more constant supply of air and inducing a more rapid end vigorous plant growth,

PACKING MEDIUM FOR STORING BULBS, ROOTS AND TUBERS
HORT-I-LITE is the ideal material to use for mixture and temperature control, insulating against excess moisture and dehydration, as well as maintaining an even temperature.

TABLE OF GROWING MEDIA AN CONSTANT LIQUID FEED FORMULAS

 
Tropical Plants
Flowering Pot Plants
Cactus
Orchid Seedlings
Percent by volume bulk ingredients
 
 
 
 
Sphagnum peat moss (loose)
50
25
-
-
0-1/8" bark or sawdust (raw)
-
50
50
67
1/16"-3/16" Pumice
50
25
50
33
 
Chemical Additives, lbs./yd.
 
 
 
 
Potassium nitrate
1
1
1/2
1/2
ParEx 31-0-0
-
2
2
2 1/2
Single Superphosphate
2
2
1
2
Calcium carbonate lime
3
5
5
4
Dolomite lime
3
5
5
4
Iron sulfate
1/2
1
1/2
1
 
*PPM in liquid feed
 
 
 
 
Nitrogen
150
225
100
100
Phosphorus
30
30
30
30
Potassium
100
175
75
75
Calcium
75
75
75
75
Magnesium
15
15
15
15
Sulfur
15
15
15
15
Copper
.07
.07
.07
.07
Zinc
.06
.06
.06
.06
Manganese
1
1
1
1
Iron
1.7
1.7
1.7
1.7
Boron
0.3
0.3
0.3
0.3
Molybdenum
0.05
0.05
0.05
0.05

* Many elements may be supplied by natural occurring minerals in the irrigation water or impurities in other ingredients

 

California Lightweight Pumice, Inc., San Clemente, CA 92672