A poll of 1,250 UK parents of school-age children suggests 44% of youngsters are now spending more time playing outside than they did two years ago.
Many parents recognise that trips to local parks and open spaces can be cost-effective days out.
But time and the weather are the greatest obstacles, the survey adds.
The research for food manufacturer Arla's Kids Closer to Nature campaign, suggested 70% of parents are spending less on entertaining their children than they did two years ago.
And three-quarters of the parents surveyed said they knew they could have a cheap day out visiting parks and green spaces. Four out of 10 opted for a budget trip to the seaside.
Author and children's play campaigner Tim Gill said: "Times are hard, so parents have to make savings.
"But the good news is that families are realising that fresh air costs nothing.
"Getting under the open sky - whether in a local park or the great British countryside - is the perfect way for kids to explore, have adventures and feed their curiosity and imagination."
And most parents appeared to understand how playing and exploring outdoors could be fun and educational.
But the survey also suggested that children are still missing out on some traditional outdoor childhood activities.
Just 55% of parents polled said their child had climbed a tree, compared to 65% who said their child owned a television or DVD player.
And while the research suggested 68% own a computer games console, only 59% have ever flown a kite.
About half of children have never built a den and just under half can play a skipping rope game, it added.