There was a time when tumbleweeds this time of year created a thorny problem for Manteca.

Before the 120 Bypass was revamped to two lanes separated by a median in the mid-1990s from being two lanes with alternating passing lanes, concrete K-rail placed to prevent head-on collisions tended to “catch” a lot of tumbleweeds.

It poised an issue for Caltrans crews to clear the tumbleweeds before enough stacked up to interfere with traffic.

And catching a tumbleweed under your car driving on the Bypass could be a joy.

Tumbleweeds on the 120 Bypass, and even in central Manteca, have diminished steadily since 1998.

That’s when the first housing developments broke ground on what had been expansive fields and orchards with generous amounts of sandy loam.

Not only can sandy loam be conducive for Russian thistle and similar shrubs that break off at the stem when they dry out to become tumbleweeds, but the soil type also easily percolates moisture that helps generate tule fog from the ground.

There was a time when there were signs along the 120 Bypass at every 100-foot intervals to give motorists a sense of limited sight distance.

It is also why the 120 Bypass through Manteca was the second place in the Central Valley to have electronic message signs installed by Caltrans.

The first ones went on a section of Highway 99 near Fresno.

The two sections were selected due to their notoriously thick tule fog.

As development has occurred south of the 120 Bypass, not only have the amount of tumbleweeds plummeted but the intensity of tule fog has weakened.

The tumbleweeds in central Manteca popped up primarily along the abandoned Tidewater Southern Railroad that is today a bike path.

Typically, the city cleared the area out of the shrubs in the right-of-way they purchased.

But that didn’t happen in 1999, a year when the bike path was “completed” but the city was having a dispute with the contractor and refused to accept the job as finished.

Because of that, the city didn’t do any maintenance — including tumbleweed abatement — for more than six months out of concern doing so would imply they had taken control of the project.

Meanwhile, people were using the Tidewater.

In several spots, they would encounter a tangle of tumbleweeds completely blocking the path.

The city finally settled the dispute.

The clean-up ended up costing in excess of $5,000 between crews and an inordinate amount of garbage truck trips to the landfill.

Not only was the tumbleweed crop not nipped in the bud before the shrubs grew and broke off at the stem, but the mature thorny tumbleweeds proved next to impossible to compact.

It also wasn’t usual for years on the edge of town for tumbleweeds to blow into neighborhoods especially to the north of Louise Avenue.

Kids would sometime gather them up and make tumbleweed forts.

To contact Dennis Wyatt, email dwyatt@mantecabulletin.com