BOSTON (AP) – With the ramps built and new roads open, the long-awaited landscaping that’s part of Logan International Airport’s 13-year modernization program is beginning. But it’s a lot trickier than planting a few trees.

The $10 million Logan landscaping plan must use greenery that doesn’t attract birds, which can get caught in jet engines, or insects, which can board planes and wreck agricultural havoc elsewhere, The Boston Globe reported.

That means that Logan’s new gingko trees had to be male because females drop seeded stinkbombs that attract birds.

Plantings avoid shades of red and violet that attract Japanese beetles.

The grass around the airfield is red fescue, which doesn’t produce seeds so it doesn’t draw birds.

And those watering the acres of new greenery are careful not to leave puddles, which lure insects, which lure birds.

Airports around the world deal with similar issues, but Boston has some extra concerns because it’s in the heart of a major highway for migratory birds called the Atlantic flyover.

As a result, plantings are chosen so that “when (birds) see Logan, they keep flying,” said Gary Tobin, deputy director of airport facilities for the Massachusetts Port Authority, which runs the airport.

The reason for such caution can be found in statistics from Bird Strike Committee USA, which monitors wildlife and aircraft.

The group says about 56,000 bird collisions with civilian aircraft were reported to the Federal Aviation Administration from 1990 to 2004.

Wildlife accidents with aircraft annually cause more than $600 million in damage, and about 200 people have been killed worldwide by such accidents since 1988, the committee says.

Logan has reported no such recent accidents, according the group.

Logan was once a concrete jungle. But after the airport’s $4.4 billion modernization, 19 of a planned 27 acres have been planted and landscaped over the last year with river birches, junipers, inkberries, and 20,000 perennial bulbs.

Despite the precautions, it’s tough to keep nature out. Any animal carcasses found on airfield and airport grounds are shipped to state biologists to discover what the animals were eating. If the food source is found on airport property, maintenance crews get rid of it, often with chemicals.

Last summer, the airport was briefly plagued by grasshoppers, which had begun to attract starlings, which gather in large numbers.

The grasshopper population was eradicated with chemicals.

“We had to deal with them,” said Scott Arneil, Massport’s supervisor for facilities maintenance.