Teachers do not need the great outdoors to deliver the foundation phase - a corner of the school playground will suffice.
That was the message given by outdoor learning experts last week at the first ever Learning Through Landscapes Cymru conference.
The National Botanic Garden of Wales, in Carmarthen, provided a stunning backdrop for the one-day event, which involved teachers getting stuck in to activities such as pond-dipping and den-building in practical outdoor learning workshops.
The foundation phase - the Assembly government's groundbreaking, play-led curriculum for under-sevens - encourages teachers to make good use of the outdoors whatever the weather.
Trevor Roach, an education consultant who specialises in outdoor play, told delegates that health and safety fears, and "distractions of technology", meant children had limited experiences outdoors.
"If you can create the right environment out of doors for children, it's always better than being indoors," he said.
Mr Roach, who has been a proponent of outdoor teaching for 22 years, said even the most dull playground, with "wall-to-wall tarmac", could be transformed into an outdoor classroom easily and cheaply.
Even the smallest patch of earth could contain fascinating plant and insect life worth studying, he said.
But school grounds needed to be managed effectively, so children could interact with them and gain a sense of belonging, Mr Roach said. Then they would feel in charge of their own learning experiences.
"Often we cover the outdoors with rubber and shelters. That's not outdoor provision," he said. "It's just more draughty indoor provision. We need design that meets the needs of the school."
Teachers should give pupils as much access to nature as possible, he said. One of the simplest ways to do that was to grow food.
"I can't think of a better thing to do with children than grow a potato and dig it up. The thrill and excitement, the awe and wonder is unforgettable," he said.
Clare Revera, a Learning Through Landscapes consultant, urged teachers to take lessons outside whatever the weather. She said if such lessons were limited to sunny days, children would miss the unique opportunities that different conditions provide. Different seasons offer different sensory experiences that arouse children's sense of fascination and wonder at the natural world, she said.
"There's no such thing as bad weather, just inappropriate clothing," she added.
She suggested that teachers should create a "seasons box" containing cheap, simple items that could give pupils the best experience of all types of weather - for example, different-shaped containers for collecting rain; light-reflective objects for sunny days; and a variety of materials for making wind chimes.
Teachers and other practitioners left the conference feeling "inspired" and "full of ideas".
Meriel Jones, forest school leader at Hawthorn Primary in Cardiff, which is moving sites, said she would use what she had learnt to plan the new outdoor area.
"I was inspired to give the children a say in what they want," she said. "That's important because they will feel it's their space."
Emma Davies and Anita Bean, at Fenton Community Primary in Pembrokeshire, are planning to transform their school's large outdoor area. Ms Davies said: "We are really excited. We're going to raid junk shops for cheap resources for outdoor play in different weathers."