Irrigation and foging

The plant's support

All plant fix itself by its root system to a substrate to stand. This substrate can be just about any thing: soil or an inert materials such as a mixture of sands, vermiculite, perlite, rockwool, coco fiber, silica-balls, clay-balls or any other possible product. In all cases, the plant, using his roots system, will get the necessary nutrients in the presence of oxygen. The selected substrate has to be easy to penetrate for the roots, allow good nutrients retention, excess water drainage and enough oxygen circulation. Many substrates have different capabilities considering the water and the amount of nutrients retention needed by plants. The management of irrigation changes with the type of substrate. Many substrates require 4 to 12 waterings of 5 to 30 minutes every day... It is difficult for an amateur/gardener to water that number of times by hand. It is better to program the irrigation. Since our aim is at indoor gardening, the following discussion is oriented towards the programmed and repetitive watering often used with different techniques of hydro culture or hydroponic gardening.

How to do good watering!

In hydroponic gardening, the nutrients enter the plant dissolved in water. The quantity of nutrient solution and the number of repetitive waterings change depending on the substrate used and on the maturity stage of the plant. The plants need more water under lighting than in the dark. The plants growing in moderate temperature need less water than plants developing at higher temperatures. Every gardener has to experiment and search for his own irrigation schedule to get optimum results. The method of irrigation always means a proper volume of solution per application and a number of waterings at regular intervals. The method has to be adapted to the growing process. The larger the plants grow, the more nutrients and water are needed per application and the delay between two waterings should be reduced. The ideal tool to manage the watering process is a repetitive timer often called a "cycle timer" (Figure 1). This type of timer should be easily adjustable to suit all watering plants need which are increasing with the maturity stage.

Figure 1 Cycle timers IGS-010 (a) and IGS-011 (b) developed by PLUG'N'GROW give possible different adjustments during the lighted and the dark periods.

Automatic time-switch and watering

The quantity of water to supply by each watering is generally determined by the flow rate and the time the pump runs to distribute water to all plants. The delay before repetition is also adjustable to make sure that the substrate remains wet. After the watering, the substrate drains and dries gradually. The delay between two watering has to be adjusted to make sure the nutrient solution remains available to the roots. It is very important between two watering that the oxygen enters the substrate and allows the largest needed intake of nutrients and water. A good cycle timer, as needed in horticulture, allows different pumping-watering durations and appropriate delays in between for both the lighted and the dark periods. That type of timer has a photoelectric cell enabling detection of "dawn" and "dusk" and notices when lamps in the indoor garden turn on or off.

Good advice for irrigation

The best possible recommendations a gardener can get concerning the choices for a growing method, the substrate, the watering equipment usually come from an experienced gardener or from competent people in a specialized store. Many stores in indoor or in hydroponic gardening can provide good and competent advices. Also, a serious gardener should buy an indoor gardening manual from a specialized store.