This caused delays and police investigations that ramped up further costs to an already exorbitant imports market.
Coslett was speaking at a plant procurement seminar at Wyevale East Nurseries, with a global slant. Wyevale East director Richard McKenna said few designers and specifies realised the costs involved in growing or importing trees.
Transport alone for just one order racked up costs of at least £6,000, with pots and compost costing £1,000. Yet few people understood the most basic tree-care principles. Common faults were leaving footballs uncovered, removing protective wire mesh around roots and watering incorrectly.
Designers meanwhile had to "stop hiding behind a cup of coffee at their desk" and visit as many nurseries as possible to "walk the lines". It was a good idea to photo trees in autumn, spring and summer to grasp year-round shape and foliage colour.
"The internet is wonderful and has transformed the world but unless you know what you are looking at you've got problems. I knew a designer who created a garden using only Google.
"It was a wonderful design but the trees were not available and he knew nothing about shape, size, optimum growing conditions and the pros and cons of containers verses rootballs."