Dry, arid weather and a critical lack of water make landscaping and landscape maintenance particularly difficult and challenging in Israel. As a result, many throughout the world look to Israel to see what can be done to conserve water without sacrificing beauty and quality.
Although coarse grades of Perlite have been used for years for many peat mixes, the use of 100% Perlite has been investigated for several years now. Essentially, Perlite offers many advantages: it is extremely lightweight, it can absorb and provide a large amount of both air and water, it is sterile and has a neutral pH, and it can be very tolerate of subtle changes in soil conditions.
For these reasons, its use in 100% Perlite landscaping and in hydroponic growing bags and pots has been growing steadily throughout the world. And in many of these hydroponic systems, finer grades began to be used more and more since the finer grades of Perlite can provide more than enough air for plants, and also retain substantial amounts of water. With this in mind, many have turned to using finer grades of Perlite in both regular container (pot) production, and in landscaping.
Several years ago, representatives of Agrakal and Habonim Industries in Israel began working with landscape and landscaping companies to convince them of the advantages of using 100% fine Perlite in large commercial outdoor containers. And today, one of the more popular and successful systems is being used in very large pots and planters in malls, hotels, resorts, convention centers, roof top gardens, and private commercial landscaping.
With the sides removed, the extensive root system of these citrus trees grown in 100% Perlite can be seen.
Additional Advantages of 100% Perlite or Perlite/Peat Moss Growing Mixes
Essentially what has been developed is a system whereby layers of materials are placed in large containers which have drainage holes along the bottom. These containers often are lined with plastic to prevent evaporation through the walls of the container. The following layers are then placed in the unit:
First layer: Drainage layer Perlite (Coarse)
Second layer: Growing layer Perlite (Fine)
Third Layer: Volcanic Stone or Organic Mixture (to make it brown)
The first layer contains the coarsest grades of Perlite so that excess water can be drained out of the container when necessary. With careful control of watering, there usually will not be too much excess water to drain. Nevertheless, some provision does have to be made to allow excess water to drain away when necessary.
The second layer is the real growing section of the system. This is the layer where Perlite seems to provide enough moisture and aeration for healthy plant growth without the need for any other ingredients like peat moss, vermiculite, or composted materials. Since nutrition is being added in the water, the challenge of the growing layer is to provide aeration and as much water holding capacity as possible without holding so much that the roots drown. Fortunately, fine Perlite seems to be the perfect media for this.
Finally, the third layer is added for cosmetic purposes. Most homeowners and even many professional growers feel any media should be brown, and so the third layer is added to offer a brownish color while also giving the system enough weight on top so that the Perlite does not blow away.
In comparison studies, these 100% fine Perlite systems have resulted in plants which are growing better, with less water, and with far less maintenance.