A science garden: illustrating various topics in biology

Wildlife gardens are increasingly popular within schools – but have you thought about creating a science garden?

Science gardens can be a living, growing example of key biological concepts in the curriculum, encouraging students to think more deeply about a range of topics.

“I’m planning to create a science garden at our school, to illustrate key topics in biology. Can you help me select plants to illustrate the following:

• • Genetic variation within a species
  • Hybridisation
  • Mutation (both naturally occurring and induced)
  • Mendelian Genetics
  • Plant evolution
  • Chimeras”

Genetic variation within a species:

Peas can be an excellent way to demonstrate this, as is done in the Genetics Garden at Cambridge University Botanic Garden. You might include wild Pisum species, a selection of landraces, some modern cultivars – both commercial and domestic, and examples of genetic reserve stock which have characteristics that are currently of interest but not of economic significance (as yet!).

Geraniums (Pelargoniums) are also excellent for this – there is a very wide range of cultivars showing different flower and leaf colour and growth form and even a lemon scented one. Most are easily available at garden centres and have the advantage that they stay in condition for a long time during the summer season. I guess any plant fancier could provide other examples – Fuchsias, tulips, Primulas – the list is endless and with care a year round display should be achievable.

Hybridisation:

The history of garden plants is littered with this – Primulas and roses would be good examples. I guess there must also be hybrid wheats that could be compared with parental varieties.

Mutation:

I had a wonderful pink flowered Pelargonium that had variegated leaves – every now and then it would throw up an entirely white shoot which I assumed was a somatic mutation. There are plenty of commercially available irradiated seeds that can be grown to show the effects of ionising radiation.

Mendelian genetics

Peas, genetic maize, tomatoes, tobacco etc as found in the Philip Harris catalogue.

Plant evolution

I could really go to town here. I’d start with mosses and liverworts and run through the major Pteridophyte groups. It would be great to get some of the S. American horsetails and clubmosses into cultivation here – they would really give a feel for what an early Carboniferous forest must have looked like. For the ferns one could have a selection of homo- and heterosporous types and then move onto Cycads, Gymnosperms and Ginkgo – the only modern seed plant to rely on water for fertilization. The focus would be on the life cycles. Then a celebration of the flowering plants as the group that really cracked the problem of doing away with free water for fertilization.
There’s some great stuff here and some key questions which haven’t really been answered yet.

Chimeras

Again the history of many garden plants depends on these and reference to any good garden encylopaedia should give examples – Bouvardia (for which a greenhouse would be needed) and Auriculas are two examples I turned up in my library without delving too deep. Again I suspect that the appropriate varieties of whatever was chosen would be available in good garden centres or through BGEN or RHS channels.

Barry Meatyard (SAPS)