Dry Farming Tomatoes: Lessons From a Volunteer Vine
This summer, a small surprise grew in my yard. A grape tomato plant popped up on its own in the gravel next to my carport. It gets full sun, sits in rocky soil, and I’ve never once watered or fertilized it. Yet, against all odds, the plant is thriving. Each week I pluck handfuls of sweet, flavorful tomatoes—proof of just how resilient these plants can be.
That little volunteer tomato sparked my curiosity and sent me down the rabbit hole of dry farming. I soon learned that what I was witnessing wasn’t a fluke—tomatoes are one of the most adaptable crops for this technique, and researchers right here in Oregon have been studying it in detail.
What is Dry Farming?
Dry farming is a method of growing crops without supplemental irrigation. Instead, plants rely on the moisture stored in the soil from winter rains. Farmers plant them farther apart so roots can spread wide, and they cultivate the soil to reduce water loss.
While this may sound risky in our hot, dry summers, tomatoes in particular respond surprisingly well. In fact, many dry-farmed tomatoes are known for having more concentrated flavors compared to their irrigated counterparts.
OSU’s Research in the Willamette Valley
Oregon State University has been conducting dry-farming tomato trials at the OSU Vegetable Research Farm and on partner farms across the Willamette Valley. Their goal: to identify varieties that can handle our summers without irrigation while still producing high yields of marketable fruit.
A few highlights from their findings:
Variety matters. OSU’s 2020 and 2021 trials found that small-fruited types like cherry and grape tomatoes almost never suffer from blossom end rot, making them very reliable choices for dry farming.
Bigger fruit can still succeed. Varieties like Spring King and Tiffen Mennonite consistently performed well across years, producing firm, flavorful fruit with relatively low blossom end rot .
Grafting helps. When varieties like Big Beef or BHN-871 were grafted onto vigorous rootstocks such as Fortamino or DRO141TX, yields more than doubled, fruit size increased by 30–40%, and blossom end rot dropped by over 80% .
Flavor and resilience. Dry-farmed tomatoes often develop thicker skins and richer flavor profiles—a bonus for both home gardeners and chefs looking for intensity.
Despite record-breaking heat in 2021, OSU found that grafted plants in particular could withstand stress, producing firm, marketable fruit even in tough conditions .
What It Means for Home Gardeners
For me, the lesson came from that scrappy little grape tomato by the carport: tomatoes are tougher than we often give them credit for. With the right soil and a bit of space, they can survive—and even thrive—without irrigation.
If you want to experiment with dry farming at home, start small:
Choose cherry, grape, or paste varieties, which handle stress best.
Plant them in deep, well-drained soil to maximize root access to stored moisture.
Space plants farther apart than irrigated gardens—think 3–4 feet instead of 2.
Skip the water after transplanting, letting roots search deep for what they need.
The payoff? A tomato with bold, concentrated flavor and a plant that proves resilience can sometimes grow where you least expect it.