All the plants ,trees etc. are living beings.It is very well proved by science that plants do respond the way other living beings [ like us] respond. They too have emotions. Apart from doing the necessary things like fertilizing ,watering etc. , it would help if you talk to them . It has a very positive effect on them.You can also let some good , soothing [ or some spiritual music] playing around them . The positive vibes around leave a great impact on a plant's growth. I can assure you it is a tested phenomenon.
You yourself can check it out by growing two plants simultaneously and caring each plant the different way .You 'll soon notice that the plant to whom you had given a personal affection is growing on a more faster rate than the other one.
Some of these ways can be :
1. Calling each of them by an in individual / lovely name.
2. Each time you come and go out of the house, you can call them a little Hi and even a Bye.
3. You talk to them as if they are listening.
4,You can caress them or sometimes even kiss them ,while watering them.
Try it out !
you'll soon see the results.