An Introduction To Hydroponics Gardening For Beginners (Part
2) Plant Needs
By John R. Haughton
1 - Part 2 - Part
3 - Part
4 - Part
THE BASICS OF HYDROPONICS.
What Do Your Plants Need?
All plants need the correct conditions in order to grow to their full
potential. Plants grown using hydroponics systems are no exception to
this basic rule. Like their soil grown cousins they need sufficient
light of the correct wavelengths, a suitable temperature, an adequate
water supply, enough oxygen, mineral nutrients and support for their
Sufficient light of the correct wavelengths, used by the plant
at the growth stage it has reached, is essential for its survival.
Plants use lots of light, at least 8 to 12 hours each day, in order to
make carbohydrates from CO2 and water. Chlorophyll, the green color in
plants, absorbs the sunlight and uses its energy to synthesize these
carbohydrates. This process is known as photosynthesis and is the
basis for sustaining life in all plants. Because animals and humans
get their food by eating plants, it can also be said to be the source
of our life.
Artificial lighting is generally a poor substitute for sunshine,
because most indoor lights provide insufficient intensity to produce a
mature crop. High intensity lamps such as high-pressure sodium lamps
can provide more than 1,000 foot-candles of light. The hydroponic
gardener can use these lamps very successfully in areas where sunlight
is inadequate. The fixtures and lamps, however, are usually too
expensive to be viable for a small commercial operation.
It is important to allow adequate spacing between plants as
this will ensure that each plant receives sufficient light in the
grow-room. For example, tomato plants, pruned to a single stem, should
be planted so as to give 4 square feet per plant, while European
seedless cucumbers should be allowed 7 to 9 square feet and seeded
cucumbers about 7 square feet. Lettuce plants need to be spaced 7 to 9
inches apart within the row and 9 inches between rows. Most other
vegetables and flowers should be grown at the same spacing as
recommended for a conventional garden.
A suitable temperature is required for the plant to grow normally.
Temperatures that are too high or too low will give rise to abnormal
development and reduced production. Summer vegetables and most flowers
grow best between 60° and 80° F, while winter vegetables like
spinach and lettuce prefer temperatures of between 50° and 70° F.
An adequate water supply is not normally a problem when using a
hydroponics system, since the basis of hydroponics is the supply of
water containing nutrients in solution. Having said this however,
there are some systems which can give rise to inadequate watering,
with the consequent detrimental results to your plants. Ebb and flow
systems which are not checked on a regular enough basis, can run short
of nutrient in their supply tanks, as can continuous flow systems.
Most, if not all, automated hydroponics systems can have disasters if
they are not monitored closely. A blocked or burst pipe, or a pump
failing can result in lack of nutrient flow, which, coupled with the
intense lighting and the correct ambient temperature in the grow-room,
will result in dry roots and severe damage to, or even the death of,
Oxygen is a basic requirement of most living things. Plants
need oxygen for respiration, so that they can take up water and
nutrient. In soil systems enough oxygen is usually available, but
plant roots growing in water will quickly use up the supply of
dissolved oxygen. This can damage or even kill the plant unless
additional air is provided. A common method of aerating the nutrient
is to bubble air through the solution. Continuous flow and aeroponic
systems do not usually need supplementary oxygen.
Mineral Nutrients are needed by most green plants. They must
absorb certain minerals through their roots in order to survive. In
conventional horticulture these minerals are supplied by the soil and
by the addition of fertilizers such as manure and compost. Nitrogen,
phosphorus, potassium, calcium, magnesium, and sulphur are needed in
large quantities, whilst the micro-nutrients, iron, manganese, boron,
zinc, copper, molybdenum, and chlorine are also needed, but only in
very small amounts.
Support is normally provided by the soil that surrounds the
growing plant. A plant grown using hydroponics however needs to be
artificially supported. This is usually done with string or stakes. It
is possible to buy inexpensive automatic string reels to support your
plants as they grow. This cuts out the tedious task of having to keep
re-adjusting the strings on fast growing plants.
Copyright (C) 2004, 2005. J R Haughton. --- All Rights Reserved ---
A partner in a thriving retail hydroponics supply business, Rickie
Haughton is the owner of http://hydroponics-gardening-information.com/
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