This is classification of plants below the level of species which share common characteristics but would freely interbreed with other varieties of the same species if the opportunity arose. For this reason different varieties are often separated geographically. When writing the name of a plant the variety name is written in italics or underlined, is immediately preceded by var. in normal type and this follows the species name. There tends to be a lot of confusion between variety and cultivar but the former only relates to plants which originate in the wild and the latter to plants which originate in cultivation.


This is a plant which has been selected in cultivation because of specific characteristics it shows which separate it from its wild origins and other cultivars. The rules regarding what is a cultivar, how it is named and how the word is used are laid down in the International Code of Nomenclature for Cultivated Plants. Only plants which are not found in the wild can be called cultivars and to show that they are the cultivar name is written in normal upright letters and enclosed in single quotation marks.


This is a water based solution which has a Ph above 7. Most alkaline soils (also called basic soils) lie in the range 7 to 9.


This is a water based solution which has a pH below 7. Most acid soil lie in the range of 7 to 5 though some peat soils may be lower.



In simple terms this is how acid or alkaline something is – only a water based solution can have a pH. A pH of 7 is neutral, below 7 is acidic and above 7 is alkaline. The only way to know the pH of a soil is to measure it, either by adding it to a solution which changes colour according to the pH or using a pH meter. Both have there draw backs, with the solution it can be hard to check the colour as the soil discolours the liquid while on the other hand pH meters; if they are to be reliable they are expensive and need constant recalibration with a buffer solution. I’m very dubious about how reliable the ph meters for the domestic market are and I would say for your own garden the kits of indicator solutions are probably better.


Don’t get too hung up on the absolute accuracy of individual test as the pH of soil is vary variable and you may well find slightly different readings in different parts of your garden The advent of pH metes has lead to people publishing the recommended  for plants down to a tenth. I don’t really see this has any practical value.

Sequestered Iron

When plants are grown in a soil which is to alkaline for them they suffer from iron deficiency as a result of the effect the pH has on the nutrients which are available to plants growing in it. Sequestered iron is iron in a form which is not affected by the pH and so it remains available to the plants. It is really only a short term measure so it has to be regularly reapplied to the plants.

Botanical Latin

Botanist quickly found Latin lacked words they needed to describe the parts of a plant, the Romans having never seen any need to do such things, so they modified the language for their own needs. The school Latin you may have learnt  has evolved considerably since the Romans; to the point a Roman would hardly recognise it. This has lead to Botanical Latin, which has branched off from ‘School Latin’, and has developed its own means for words and grammar. Anyone wanting to learn more would do well to look at Botanical Latin by William T. Stearns which is the standard text on the subject. Its very heavy going though!


What soil is should at first sight be pretty self evident but to a soil scientist, yes there is such a person (they study soil), soil is a very complex thing. The problem is we all tend to overlook soil; it’s that muddy stuff in the garden. It is though a complex and delicate ecosystem in its own right. The main parts are:

  • Soil water
  • Organic mater
  • Soil flora
  • Soil fauna
  • Mineral components
  • Soil air