The Good, a small e-commerce firm based in Portland, Ore., has been besieged by an armada of Silicon Valley technology giants including Salesforce.com and Airbnb that have invaded the region in the past year or two and are cherry-picking skilled job candidates.

As a result, it’s taking the company — with seven full-time workers and another seven part-timers — about three months to fill openings, up from two months a year ago, says company President Jon MacDonald.

“There are lots of people just looking to move to higher-paying employers,” he says.

At 4.7%, the unemployment rate was near its 10-year low in February, down from 4.9% a year ago, supplying employers a smaller pool of available workers. The tight labor market is making hiring a struggle for most companies, but small businesses face an especially daunting task. While some are adding or sweetening benefits and salaries, they typically can’t compete with the packages offered by larger firms.

Thirty-two percent of small businesses had job openings they weren’t able to fill in February, the largest share since 2001, according to the National Federation of Independent Business’smonthly survey, which mostly covers companies with fewer than 50 employees. Seventeen percent of the firms cited “quality of labor” as their biggest problem, a 10-year high. And 85% of those seeking workers said there were no, or few, qualified applicants for their openings.

“The big firms skim the better-skilled people,” says William Dunkelberg, NFIB’s chief economist. That, he says, can contribute to more…