How to Protect Your Strawberries From Pests and Disease

Before I moved to Portland, I didn’t understand how passionate people can be about strawberries. But once I started growing strawberries, I came to understand that a disproportionate percentage of berries I grew would be lost to bugs, wildlife, and disease. Since summer is short, I’ve worked hard to minimize my losses, and I have suggestions for protecting these precious garden jewels. 

Keep strawberries off the ground

Strawberries are a ground cover, spreading through runners, which create the next generation of strawberry plants. Each plant grows berries at the ends of stems, and those berries usually make contact with the ground. There, they are exposed to prolonged moisture from the soil, are easy picking for bugs, and are harder for you to spot for picking. So the obvious answer is to prevent contact with the ground. 

By planting vertically, I have room for tons of plants, and they’re not exposed to the wet soil
Credit: Amanda Blum

There are plenty of options, including the classic strawberry planter. There are many versions of this traditional terra cotta planter with multiple portholes for berry plants, and you simply plant one in each porthole. In recent years, I’ve seen Pinterest boards inundated with strawberries growing in gutters so you can elevate them above ground. I created a vertical planter, and all of these solutions have some common benefits and challenges. Because you’re not planting in the ground, your plants have less soil to root in, and that soil dries out faster. You’ll need to be conscious of this and ensure you’re using a soil that has additives to hold onto moisture, like potting soil, which usually includes vermiculite and perlite. Make sure that soil has the right fertilizer (strawberries like a slightly acidic soil) and consistent watering systems, so they always have moisture in the soil (but are not soaking wet). This lack of soil protection means your plants lack insulation from winter’s cold, so it’s unlikely your plants will survive from year to year; expect to replace them each spring. 

That said, I argue it’s worth it, because each plant has excellent exposure to sun, and the berries hang, where they have air flowing around them and are out of reach to soil-bound pests like pill bugs. The berries are easy to spot, and get sun exposure for ripening. This all makes for easy picking. Not for nothing, I love freeing up the ground for other plants. 

If you can’t go vertical with your berries, and you’re stuck with ground cover, strawberry supports may be the answer. These trellises are like a small platform your berry plant grows through, and they loft your plant enough to keep berries off the ground.  The key is to get your the supports on your plant early in the season while the plant is quite small.  The nice thing is that there’s nothing particularly advanced about these supports; you can grab them from all sorts of providers, and even 3-D print them yourself. If you grow on the ground using these supports, you should still consider additional pest protections.

If nothing else, plant berries at the edge of raised beds, so they’ll grow over the edge, and be elevated off the ground.
Credit: Amanda Blum

How to protect strawberries from pests

If you’re not going to go vertical, you’ll need to do some work to beat the pests to your harvest. For common strawberry villains like pill bugs, spreading around diatomaceous earth (a silica-based powder commonly called DE) is effective, but it requires multiple applications. DE is popular because it’s “non-toxic” and won’t hurt earthworms or your fruit. Slugs are another berry killer, but DE can’t kill slugs; for effective slug control, you need Sluggo (a slug and snail treatment), which will also require multiple treatments (after rain, etc). The difference is that Sluggo is iron phosphate based, and it can build up in soil; so while it is effective, you don’t want to overuse it. Following the directions is important. 

The redness of strawberries makes them perfect picking for rodents and birds, and while you can’t fake out a rat (effective rat traps are your only bet), you can fake out birds. Gardeners sometimes paint rocks the approximate size of strawberries the same red color and lay them among the berry plants. Birds will peck the rocks and eventually be trained to leave the berry patch alone. While this one sounds suspect, I’ve been doing it for years, and have seen it work.