When first planting you should water every day or two for a couple of weeks, making sure not to let the root ball dry out, then gradually back off the watering frequency so that after 6 weeks you are watering every two-three days or so in the summer and every week to two weeks in the winter.
For example, their Grammar book is only $15. The total cost of books at a college level will usually be much higher. Depending on the number of credits, the price can vary from $200-$1000 per semester. According to CollegeBoard.com, the national average for college textbooks is $1,137 per year.
According to the National Association of College Stores, the average price of a new textbook increased from $62 (in 2011 dollars) in 2006-07 to $68 in 2011-12. Students also rely on textbook rentals, used books, and digital resources.