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Growing Exotic Plants & Plant Hardiness

Brugmansia Plant Care Guides

Want to create a subtropical paradise in your garden?

Check out your gardens plant hardiness zone below.

What's my USDA Plant Hardiness Zone? Click the Map to find out!

USDA hardiness zones are used to identify a regions lowest temperature to assist gardeners to judge which plants will withstand those conditions. This is a guideline only. The maps do not factor in micro-climates, topography, precipitation, humidity or extreme temperature highs/lows. Weather should be monitored to protect plants.


Creating an Exotic Garden

Exotic subtropical plants can make a great addition to any garden. We grow a variety of exotic looking plants to help you achieve brilliant flowers and fabulous foliage. The photos below give an idea the impact these stunning plants can have on a summer garden. We supply both the banana plants and Brugmansia featured below:


Angel Trumpets against a Banana Backdrop

Exotic plants can enhance any garden space large or small.  An important feature is that the garden is well protected from cold northerly and easterly winds in winter and is generally south facing for summer.  If it is protected by structures (walls, buildings, fences) or there is a micro-climate within the area this will help with protection and growth. Below is a garden design I created in a small south facing area featuring Echium, Musa Basjoo, Phoenix palm, Gunnera and Canna.

Garden Design

Sub-tropical plants in a small garden space


Tresco Abbey Garden, Isles of Scilly

Plant Hardiness in the UK

Plant hardiness is generally considered to be the lowest temperature that a plant can withstand during the winter. The US Hardiness zones are based on the average annual extreme minimum temperature during a 30-year period in the past, not the lowest temperature that has ever occurred in the past or might occur in the future. Gardeners should keep that in mind when selecting plants, especially if they choose to "push" their hardiness zone by growing plants not rated for their zone. In addition, there might still be microclimates that are too small to show up on the map.


Microclimates, which are fine-scale climate variations, can be small heat islands—such as those caused by tarmac and concrete—or cool spots caused by small hills and valleys. Individual gardens also may have very localised microclimates. Your entire garden could be warmer or cooler than the surrounding area because it is sheltered or exposed. You also could have pockets within your garden that are warmer or cooler than the general zone for your area or for the rest of your yard, such as a sheltered area in front of a south-facing wall or a low spot where cold air pools first. No hardiness zone map can take the place of the detailed knowledge that gardeners pick up about their own gardens through hands-on experience.

When selecting an Exotic Earth Plant please reference to the Hardiness scale.  Each plant will specify their preferred zone. Below is the Trebrown Plant Hardiness map for the UK with USDA hardiness rating key:

It is important to understand that average minimum air temperatures (protected from wind & direct sun) are used in defining these zones. Ambient temperatures will be lowered by local frost pockets and by wind-chill. Although, plants do not suffer from the effects of wind-chill like we do, they can get dehydrated and suffer from windburn in cold easterly winds. Therefore, you must read these zones as the maximum potential temperature for an area once windbreaks have been put in place. For example - If you see from the map that you are in a potential zone 9a then you can over winter plants outdoors, which are suitable for zones 8b, 8a, 7b etc. You will only be able to over winter plants suitable for zone 9a once protection has been put in place and a favourable microclimate created.

Many meteorologists call the British weather unique, but they agree it is hard to find another country in the world with weather that compares to the UK.

So what makes it so distinctly variable?

"Britain's unique weather is all down to the fact it is an island and where it's positioned on the planet, between the Atlantic Ocean and a large land mass, continental Europe. Japan is probably the only other place that has similarities to the UK when it comes to weather' (Helen Chivers, Met Office). 

Britain is under an area where five main air masses meet. An air mass is a large body of air that has similar temperature and moisture properties throughout.

There are many regional variations and microclimates in the British Isles, ranging from the nearly subtropical climate of Cornwall, to the dry semi-arid conditions of East Anglia to the Arctic tundra conditions which can be experienced in the highlands of Scotland. 


Global Plant Hardiness Zones - Climate similar to the UK

The global plant hardiness zone map below shows climates which are similar to the UK. It also highlights the uniqueness of the the British Isles considering the latitude it is situated in comparison to say Northern USA or Russia. The warm tropical maritime and tropical continental air masses play a huge role in supplying these favourable climatic conditions to the UK. As a result we can grow exotic plants in the UK with the correct winter protection.

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