The phlox are blooming and I have questions about them…. lots of questions, mainly about the tall American native Phlox paniculata, a classic British border perennial. So I turn with a relief to a new book on the subject Phlox: A Natural History and Gardener's Guide by James H. Locklear (Timber Press).

I'm looking for an expert's opinion:
* Why is P. paniculata 'David' no longer mildew resistant, was 'David's Lavender' ever resistant?
* I'm wondering if the many recent much shorter varieties from Holland are forms of P. paniculata or hybrids – and if they're hybrids, do they spread more, as we might expect (one parent does, the other not) and do they still get eelworm (again - one parent usually does, the other not)?
* What's the best way to take root cuttings and so avoid eelworm? Many home gardeners have problems with this eelworm-avoiding technique?
* Lots of ID confusions… Is 'Blue Paradise' the same as 'Blue Evening', for example, or is one being sold as the other?
* Do some varieties respond better to cutting back in May than others – so they flower on shorter plants and don’t need staking?

But it turns out that it's not that sort of book. This is an impressive and authoritative botanical work, with detailed descriptions of all the wild Phlox species. The wild distribution of each species is discussed, there are many details on the habitats of the plants at different sites, and invaluable accounts of the plants with which each species is associated – something rarely found in this detail in plant monographs and testament to the author's ten years of diligent research.

But, although enjoyably written and comprehensive when dealing with plants in the wild, the book answers none of my questions. Few cultivars of any species are mentioned, eelworm gets less than three lines, there is little on propagatrion, and cultivation advice is generally basic.

That would be fine, if there was also a book on Phlox for gardeners. But there's not. And I know from experience that once one book on a specialist plant subject has appeared – good or bad, comprehensive or not – it's very tough to persuade a publisher that another is needed.

Phlox: A Natural History and Gardener's Guide is a superb Natural History - but, sadly, not so hot as a Gardener's Guide.