"It's the seven-day restriction on workers that's going to be the challenge," explains Gabriele Ludwig, director of environmental policy at the Almond Board of California. "The buffer zones are already in effect and apply to homes and occupied buildings. Now growers must keep their own employees, and potentially their neighbors' employees, out of these buffer areas for a full week."
Required buffer zones can vary significantly, depending on factors such as the method and depth of application, rate applied, acreage treated, and whether tarps are used. Using Totally Impermeable Film (TIF) tarps can reduce buffer zone size, but Ludwig notes this practice nearly doubles fumigation costs.
Additionally, some growers may be required to have buffer zones that extend onto adjacent properties. In these cases, growers must secure written agreements ensuring neighboring landowners will keep their workers clear of these areas for the seven-day period. This requirement could pose substantial operational disruptions, particularly for smaller farms adjacent to diverse cropping systems.
"This isn't just about posting 'no trespassing' signs," Ludwig emphasizes. "It directly impacts the ability of your neighbors to manage their own operations."
Although the official public comment period on these regulations has ended and changes appear unlikely, growers who intend to fumigate should consider completing applications before January 1, 2026, when compliance becomes more burdensome.
Soil fumigants have been in the crosshairs for quite some time and the Almond Board of California continues investing in research to develop viable fumigation alternatives. Over the past 20 years, studies have explored rootstock genetics, steam treatments, anaerobic soil disinfestation (ASD), and various methods to mitigate off-gassing.
"We see that certain alternatives work under specific conditions, but universally effective and cost-efficient solutions remain elusive," Ludwig acknowledges. She further highlights the ongoing challenges, especially in sandy or hilly terrains where maintaining adequate soil moisture or conditions required for ASD proves difficult.
Ultimately, Ludwig urges growers to recognize these regulatory changes and proactively adapt their fumigation or soil pest management practices. "It's about being aware and planning accordingly," she advises. "These regulations aren’t going away. DPR has listed all fumigants – including soil, post-harvest and other uses – as “priority pesticides” which are pesticides whose use would be phased out by 2050, so growers need to strategize now."
