Watering is an important aspect of cultivation. It is water that will make fertilizers work, leach out harmful toxicities, allow natural breakdown of media, wet fine feeder roots and pass nutrients through the plant. Water high in salts will leave residues on pots, plants and in soils. Soft water will also break down soil, create an acid soil base, prevent some nutrients to be absorbed, and may even destroy some roots. The best water is a neutral one. If your water is a bit over on either side, do not get alarmed. It will be fine. But if your water is very hard or very soft, you may need to alter the water a bit or add the opposite component into your soils to balance it. Adding limestone, oyster shells, and other high pa components into your mix will create a balanced effect when watering where very soft water is a problem. Adding peat moss, sphagnum, to the soil, or even just plain cheap vinegar to your water will help increase your pa. Some fertilizers high in acid composition, can be added to your solution when fertilizing. But I haven't seen a case where these extremes are a problem for supplementation to be effectively used.
When watering, use a breaker head to make the water sprays soft and heavy. Fine stiff sprays often dislodge soil from fine feeder roots and create a pot-hole in soil surfaces. Scattering soil particles when watering is not good as it may displace fertilizer granules and released nutrients out and away from your plant. Always water with the intention to drain and leach water from the pot drain holes. This is important in releasing excess salts always present in all fertilizers. These accumulated salts are toxic in large quantities and may inhibit growth and uptake of essential nutrients by plant. Excess salts can be visible at drain holes and pot sides if there is an excess problem. Usually its too late when you can see the accumulated salts around the pot sides and rims. If you already have this problem, you must remove the plant and its soil. Use a brand new pot and new soil media. Allow the plant to be placed in a media high in aggregates to keep the watering flowing easily. You will need to continue to leach out salts from the root system each time you water. Do fertilize with a low salt solution (like Peter's) at half strength until plant can become established into its new media. Again, Miracle-Grow is too high in toxic salts and should not be used! See Miracle-Grow.
The amount of water to give a plant varies with growing season and pot weight. I use the pot weight method for determining when my plants need water. A heavy pot indicates soil still saturated with water. When this pot becomes lightweight and the media becomes a bit lighter in shade, then its a good indication to water again. I like to group my plants based on watering schedules. Small pots and growing seedlings require more water than newly transplanted pots and larger specimens. Therefore I group them according to how I water them. If you cannot afford this kind of segregation, group plants according to their needs even on the same bench or area. Always water your plants in the earliest part of the day. This will allow them to dry out and utilize some of their water in the highest light intensities of the day.
