Hi Febry:
This is Kimberly from landscape solutions for you. Thank you for asking the questions on growing crops in a poor sandy soil and also cold temperatures.
One of the problems with growing crops in cold climates is once the temperature reaches below the freezing point,(32 degrees F - 0 degrees C) the ground will freeze. Many growers put their crops in greenhouses and cold frames throughout the colder winter months. Vegetables such as peas, cabbage, broccoli, and onions are considered cold weather crops. They can be maintained in greenhouses at cooler temperatures than herbs and flowers. There are ways to protect plants to insulate them. An inexpensive way is to loosly wrap burlap around the plants. Snow is a protection for leaves and any buds. Many researchers are looking at different ways to create an atmosphere to grow different plant specimens in colder climates. Bio-domes have a controlled atmosphere for different plants to grow in a variety of temperatures. There are some herbs that are cold hardy, but most herbs require some warmth. Rosemary is a more hardy herb.
Some of your trees and shrubs will do better in colder climates. If you need more detailed specimens on trees and shrubs, feel free to follow up here.
As far as your soil conditions, whether it is a sand base or clay base, the key is the amount of water and organic material in the soil. The right mixture can be used to produce the correct conditions for plant specimens to grow. One of the steps growers take is to test their soil on a regular basis to see what materials they are lacking, as well as possibly an over abundance of other materials. Researchers are also looking at new ways to produce safe chemicals to add in colder growing climate regions.
I hope this has helped some and please let us know how you make out on your project. If you have more questions, please feel free to ask. Thank you again for asking the question here at landscape solutions for you. Come visit anytime.
Kimberly