Question
when i read in botanical books many species of flowers need different type of soil or dryness or wetness or drainage so do i have in a landscape to have different area to put my flowers, for exemple one with rich soil,another with poor soil etc....Its difficult with automatic watering systems not to put water on plants who require dryness. Thank you
P.S. excuse my poor english i am french canadian.

Answer
Alain,

Good question.  You always want to group plants accoding to their cultural requirements.

Soil is easy to take care of.  Always amend your soils with organic matter, peat, compost, etc., and you will not have soil related issues.  If you have good soils, you will have good plants.  There are no plants that require poor soils, only plants that will tolerate poor soils.  

Grouping plants is critical concerning watering requirements.  Gardeners should always try to group by watering.  This prevents many problems associated with over-watering.  

You have an irrigation system.  Hopefully it is zoned where you can control the amount of irrigation in a particular zone.  Decide which zone you want to have your "drier" plants and plant them there.  Sometimes this interferes with landcsape dplanning but is not an impossible situation.

Good luck in the garden.

Gary