Green as a color is known to have a shooting effect on humans. In ancient India the gurus used to surround themselves by greenery to help in meditation. It is also a known superstition in south india that if you feel frightened you should immediately see something green. Maybe the scientific reasoning behind this superstition maybe that the color green usually soothes the nerves. If you are prone to stress attacks and anxiety, I would suggest that you surround yourself with green as much as possible. In fact you should try to place plug plants at your workstations, at your cubicle, in you study room and even in the rest room. It gives immense relaxation. Try it for a few weeks and you will start noticing the difference on your own.
If you have a house which faces towards a lawn you can ask for anything better. Make sure you start everyday by taking in all the green around you for a few moments. There is nothing which will be refresh you mind better. You can even have your bedroom painted as thick green (instead of light green), I know its not a very commonly found color in bedrooms but give it a try. You will immediately start noticing that you feel very rested when you get up. Infact if you are prone to anger bouts you should make green color you companion. Green is known to reduce the levels of anger and frustration within more than any other color. The reason why you feel attracted to green grass is because of your body's affinity to this color.
As a practice try adding a new plant to your garden every month. Usually a lush green plant should be ideal. Flowering plants are good, but even a non flowering plant which is lush green is great for viewing pleasure. Make your garden look as flushed with green as possible, ensure that there are no traces of artifical materials like bricks, paint and concrete visible in you garden. Basically cover it up with green. Your garden would then be your ultimate medidation ground, infact you dont need to medidate just be present watching the green around you to feel completely relaxed.