A successful landscape designer must be more than a decorator. A finished project should be able to withstand a long test of time. To that end, the designer must know a great deal about plants ' growth habits and environmental requirements, soil science, tree protection, property development, irrigation design and more.

That's before the drawing up of a design.

In addition to the above - which are absolute essentials - it is important to understand and be intimately familiar with the basic design elements. That means some sort of formalized design training. A landscape architecture degree is unnecessary unless that is your career choice but there are many organizations that offer garden or landscape design training, including many tecnical or community college programs. Because a good design course requires interaction and feedback as well as a local perspective on plant selection and growing consitions, I recommend a classroom situation rather than an online program.

And FWIW, a formal garden design course of study will supply much of the non-design technical material as well. But nothing replaces hands-on experience. It would be advisable to intern with a practicing landscape designer or design/build contractor as well.