Exotic Heat Island

This is an excerpt from the Book called “Small Family Gardens  by Caroline Tilston. Continue reading to learn more about Exotic Heat Island, thanks to the author.

Design Brief 

  • Interesting plants
  • Play areas for children  
  • Lawn  


  • Den for children  
  • Raised beds  
  • Bicycle shelter 

A new extension was the impetus for changing the garden here. The brief was for a garden that the two boys (aged 6 and 9) could play in, but also one in which the adults could ‘indulge their love of plants’. 

However, straight away there was a huge problem. There is concrete nearly a metre thick on the ground and it couldn’t be removed, so there was no soil for the lawn to establish itself and no soil for plants.  

The landscape architect on the project, karen Fitzsimon, came up with an ingenious solution: she’s used roof garden technology and know-how to create a garden here. On the ground is Geovoid 30 by Green fix, which is a water-dispensing material that basically acts like soil but achieves the results in millimetres rather than metres. It holds sufficient water for the grass but doesn’t get waterlogged. And for the plants there are raised beds to create a good depth of soil. 

Creating a small wildlife pond  

Even the smallest pond will attract pond skaters, damselflies and dragonflies. In spring there will probably be frogspawn and later frogs and toads to watch out for. Around the pond greenery will allow small animals to hide safely and a sloping edge can be useful for both children and animals. A slope is safer for children as they aren’t confronted with a steep drop and if it’s covered with sand or pebbles it makes a great ‘beach’. The slope will also help animals get out of the water if they fall in accidentally.

small wildlife pond
small wildlife pond

Tips for wildlife ponds  

1 Siting the pond in a small garden you may not have a lot of choice about where to put a pond. But if you do have a choice, consider the following aspects:  

  • Try to avoid putting a pond under a tree because the falling leaves can pollute the water. 
  • If you need power for a pump you filter you need to make the pond near a power source. 
  • With a pond for wildlife one of the great things, especially for children, is to be able to sit close and watch the goings-on, so put a bench or seat nearby. 

2 Size the bigger the better, in bigger ponds you can grow a greater diversity of plants, which helps the pond look after itself. 

3 Materials For small ponds pre-formed rigid liner might be best, for larger ponds flexible UPVC tends to be a better option. Whichever you go for, don’t skimp on quality as there are a lot of strains on the liners and sunlight will tend to add to the wear and tear. 

4 Sides make sure the sides aren’t too steep for frogs. Also a rockery or lots of damp vegetation will provide shelter for amphibians. 

5 Plants Plants native to your area will be best for wildlife. These plants are the food sources and shelter that local wildlife can use best. As well as the pretties and those obviously good for wildlife, don’t forget to add oxygenators to help keep the water clear – you buy these be the bundle and need to put about 15 stems in for every square metre of pond surface area you have. 

6 Keeping it clear Murky, smelly ponds are the second biggest reason that people have for not wanting a pond in the garden (the main reason is concern about safety). Algae feed on nutrients in the water and need sunlight to flourish. So clearing out weeds, leaves and excess fish food will help keep out sunlight make sure a large proportion of the top surface is covered by planting?  

Exotic Heat Islands 

This is the name Angus White from Architectural Plants gives to the potential of gardens in large cities. He comes up with some startling statistics: for example, the minimum temperature in London in winter is comparable to the south coast of France. OK, it’s hotter in the summer in France, but it’s the minimum temperature that is important for plants’ survival and happiness. On one of the coldest nights in recent history in 1991, Angus recorded a temperature of minus 170C West Sussex. In London on the same night the minimum was minus 40C, an enormous 130 difference. This ‘heat island’ effect is huge and its benefits are little exploited.

Children’s Gardens
Exotic Heat Islands
Exotic Heat Islands

It’s not just London; in any city area the buildings and roads absorb heat during the day and release it at night. Add to this central heating, cars and people, and you have an enormous amount of heat being generated – the larger the city the more extreme this will be. 

Angus has understandable caveats about suggesting going for very tender plants. If there’s one thing we can predict about the British weather, it’s unpredictable. But do try a few less hardy plants and see how you get on.   

10 Top Tropical 

  1. Rice paper plant. A wonderful, tall plant with huge palm-shaped leaves. It can sucker, so you need to put in an underground barrier sheet to stop it spreading. 
  2. Tree fern. Probably the most common of the jungle-like tender plants, this is everywhere, but it’s everywhere because it’s such a nice plant. 
  3. Aeonium. Happy in spot, the black version slowly, slowly grows into interesting shapes. 
  4. Honey bush. This is pretty hardy and has blue-green cut leaves. It will probably die back in winter but come up again next year. 
  5. Canna lilies. With purple leaves and orange flowers, these tall plants are wonderful for late summer colour. 
  6. Ginger lily. Spectacular orange flowers and beautiful foliage. 
  7. Black banana. These provide some of the most tropical-looking foliage, don’t expect any fruit though| 
  8.  Red Cestrum. Evergreen with red flowers in summer. 
  9. Variegated soapwort. This variegated soapwort isn’t as hardy as the all green one, but is more interesting. 
  10. Mexican blue palm. With silvery blue fan-shaped leaves, this can go wonderfully well with canna lilies. It likes full sun. 
Exotic Heat Island