Written for Malaysia, this book skimps on very little when it comes to tropical gardening.
Writer acknowledges that Malaysia's seasons (Hot/Wet and Hot/Very Wet) are not necessarily the same as, say, Indonesia's or Hawaii's. Therefore, the section on cacti and succulents is a bit scant. And I wished for a little more variety in palms. What nearly makes up for this is the completeness of all the other categories... shrubs, flowering plants, foliage plants, water plants, so on. Amazing detail is given for each plant and, often, its variations. Holtum can always be relied upon to comment on, say, a plant's success at high altitude or near the sea.
Lots of suggestions for how a plant should be used in relation to other species or what size garden it requires. But no landscaping sketches... this is all imparted through the text and sometimes photos. With each listing, the reader will be able to learn rates of growth, most appropriate methods of propagation, etc. Photos excellent but not always inserted RIGHT next to the appropriate text, and sometimes a plant is listed/written about in more than one place (without any good note to this fact). All in all, though, it's a useful reference book without extraneous chit chat.
Bonus for Indonesia and Malaysia: along with plants' common English name and Latin name, we get the Malay name (usually same as Indonesian). Extremely useful for dealing with local suppliers.
I have been very happy with this huge and generally well organized book. None of the gorgeous looking Periplus or smaller tropical plant books come close to the usefulness of this book.