Since ancient times people have been using the Moon cycles for guiding their activities. Nowadays when the science has greatly advanced, it is not considered to be a superstition. There is a great amount of research which shows that a lot of lower forms of life such as plants are connected with the rhythms of the Moon and synchronize  their  activities with it.
Unfortunately, there is still a great prejudice against anything that is connected with astrology. That is why there are no scientifically verified rules of understanding the influence of the Moon’s cycles in their connection with gardening.
As the there is no consent in the scientific world about this matter, we have two different traditions of lunar gardening. Let’s call them  the American and the European,  but we should bear in mind that  this naming is not 100% precise  because researchers  from both sides of the Atlantic have contributed  into both traditions.
Each tradition has a great number of followers and its rules are supported by a number of documented experiments. But they differ greatly in some issues and contradict each other. That’s why you should choose one you will follow and stick to it.

The American Tradition of the Lunar Gardening

The rules of the American tradition of lunar gardening can be found in many books,  for example in the Llewellyn's Moon Sign Book. At the end of this article the links to some books are given. You will find a lot of useful information in those books but I’d like to discuss the main rules.
In order to get the result above the earth use the Waxing (growing) Moon. If you are going to plant your cucumbers or flowers, you ‘d better do it  after the New Moon but before the Full Moon( in this period the Moon is increasing in light).
In order to get the result under the earth, you need the Waning (decreasing in light) Moon. If you want to plant potatoes,  then  it is supposed to be done after the Full Moon but before the New Moon.
There is  a number of  fruitful signs (Taurus, Cancer, Libra, Scorpio, Capricorn, Pisces) when  it’ s better  to do everything that promotes growth. In each sign the Moons remains about 2,5 days. With the help of  the Universal Lunar Calendar you will find out  when and what sign it is in  your  time zone.
Aries, Gemini, Leo, Virgo, Sagittarius, Aquarius are considered to be barren signs. When the Moon is in these signs, you’d better do pruning or cutting, i.e. things preventing growth.
It is important to mention that that in the American tradition there is  Tropical Zodiac. It  is widely used in the Western Astrology. For example, saying that Aries people are born from the 20th of March to the 19th of April, you are referring to the Tropical Zodiac.
If you choose to follow  the American Tradition, then for lunar gardening you will need  the Universal Lunar Calendar. In this calendar you will find the dates and times of the lunar phases  and  the dates and times when the  Moon comes  into each of the signs of the Tropical Zodiac  in any part of the Earth.It is not very difficult to understand this calendar, all you need is to read the symbol explanation which is given in the calendar and you will be able to figure out what is what.