THE ADVANTAGES OF GROWING IN PUMICE
Pumice is one of Mother Nature's unique and widely useful
creations. Born of earth and fire, Pumice is essentially a whipped foam of
volcanic glass—each stone made up of highly vesicular strands permeated with
tiny air bubbles.
The physical and elemental properties of Pumice give it its
unique and infinitely useful qualities—qualities that are welcomed in a wide
range of industrial and practical applications. That includes horticulture.
PUMICE IN HORTICULTURE
Pumice Stone is available in various
grades, the 0-3 mm and 0-8 mm grades have been successfully used in the
Hydroponic Industry. The material's excellent "sponge like"
characteristics provide the all important water retaining properties, while
also giving good drainage and ventilation to the plant's root system. Generally Pumice is placed into the plant container; the volume per plant is determined
by how densely the crop is planted, eg: 2 litres per plant for
Chrysanthemums/Lettuces and up to 10 litres for sparsely planted crops such as
Cucumbers. Pumice is very financially efficient and easy to use. It can be
reused many times, on average up to 6 years for Carnations (3 successive crops)
with outstanding results.
Pumice is used widely to improve the growability of
soils—combating compaction and runoff, improving friability and aeration, and
holding moisture and nutrients in the root zone. The same properties that make Pumice an excellent soil amendment and conditioner also translate to soilless
grow media systems. With the rising popularity of high-efficiency growth
systems, especially aquaponic flood-and-drain systems, Pumice provides many
advantages as a soilless grow media.
PUMICE VS. PERLITE
Of interest to those familiar with the use of horticultural perlite
is a study done by the University of Illinois’ Department of Horticulture that
found Pumice to be physio chemically analogous to perlite, which translated into
similar behaviors and results in horticultural applications. A snippet from the
report summary: “It (Pumice) proved equally, if not even more effective in some
ways, than perlite[1].”
Pumice also provides a greener alternative to perlite and other
expanded-to-foamy-usefulness products (see sustainable and green, below).
WHY PUMICE EXCELS AS A SOILLESS GROW MEDIA
When considering which grow media to use, these key points
should be considered:
·
Nutrient Holding
Capacity— an
effective grow media must have the ability to retain that nutrient-rich water
for a time, making it continuously available to the roots between watering
cycles. This foamed glass stone is riven with countless tiny pores that
function as microscopic reservoirs to capture and store nutrient-rich moisture
and give it back to the root system as needed. That allows for less frequent
watering cycles and avoids problems like algae growth. It also saves energy and
reduces wear and tear on the watering system.
The porous, foamy nature
of Pumice also makes for an ideal environment for beneficial microbes to
thrive.
·
Drainage—Balance is so important:
a grow media must be able to shed water quickly to allow air into the root
zone, yet retain enough nutrient-rich moisture between irrigation cycles to
fuel rapid growth. The tiny, microscopic pores hold water and make it available
on demand to the root system. The large pores drain quickly, shedding water and
taking in air. The hardness and varied shape and size of the stones themselves
also prevent compaction of the media.
·
Gas Exchange— a grow media must allow free-flowing exchange of oxygen and
carbon dioxide in the root zone. The highly porous, low-bulk nature of Ponics
Stone™ facilitates an effective and positive exchange of gases between the root
zone and the environment.
·
Stability—the grow media must be
substantial enough to support a plant’s root system, as it is the root system
that support the plant and the fruit it bears. Pumice grow media is
lightweight, yet substantial enough not to float away. The grippy surface of
the little Pumice stones form a stable bedding matrix to support thriving
plants.
·
Weight—Grow beds tend to be
positioned above ground/floor level to allow a sump tank underneath and/or to
provide easy access when planting and harvesting, and that means grow media
weight is an issue. Since Pumice is essentially a foamed glass stone, it is
less dense and weighty than gravel or sand. 1.5 cubic feet of pumice media
weighs 75 pounds. Yet it is weighty enough to stay in place during irrigation
cycles.
·
Crop Balance—As a grow media, Pumice
provides good drainage, excellent moisture retention, and increased gas
exchange necessary for both vegetative and reproductive (fruit) growth.
·
Media Particle Sizes
SUSTAINABLE AND GREEN
Since the entire suite of Pumice's useful properties are
bestowed by nature, the process to prepare Pumice for market is simple,
sustainable, and green.
Our Pumice grow media is not manufactured—it is simply removed
from the deposit, crushed, dried, and screened to size.