Water is the key to successful strawberry crop

by Sally Colby
When Dan Brouwer came home with 1,500 strawberry plants in 1998, his wife Sarah couldn’t imagine dealing with that many plants. But Dan had a plan: to start a you-pick for the public.
Sarah said people were eager to come to the farm and pick Honeoye strawberries on that original ¼ acre plot. As their customer base expanded, the Brouwers continued to plant more strawberries on their Raymond, MN farm, experimenting with different varieties and keeping more detailed production records. “One year we tested five rows of Honeoye and five rows of Cavendish,” said Sarah. “We found that we got 50 pounds per row from the Honeoye and 200 pounds per row from the Cavendish. That was eye-opening. We have kept careful records ever since.”
Four years ago, when the Brouwers decided to expand production, they joined a specialty crops program through the state of Minnesota. They now benefit from the services of a strawberry specialist who evaluates the soil and plants on the farm. “He has made a big difference in helping us identify what’s unique to our situation,” said Sarah. “The soil at our farm is quite different from that in the Twin Cities area, which is two hours away. Their soil is sandier and more acidic, and ours is more clay and alkali.” The Brouwers test soil regularly, and are looking into sap testing to determine nutrient uptake by plants.
But soil isn’t the sole factor to success with strawberries. Sarah said a good crop is dependent on water, and every aspect of production is centered on ensuring a good supply of moisture to plants at the right time of year. The source of irrigation water for Brouwer Berries is two ponds, filled primarily with snowmelt. At one point, the Brouwers tried digging wells, but digging to 270’ in two spots yielded no water, so they’re looking at other options.
A drip irrigation system conserves water for plant roots, but overhead sprinklers for frost protection are a critical management point. Sarah explained the system: “We start the overhead sprinklers at about nine at night so plants are completely wet before the temperature drops below freezing. As the temperature drops below 32, the water coats the flowers, and as it freezes, the water molecules give off a tiny bit of energy that’s just enough to keep the blossom alive and not frozen. As long as we keep the water going all night long, the blossoms will be okay the next day.”
Frost protection efforts include staying up all night; checking sprinkler heads hourly to make sure the heads aren’t frozen. In the morning, after the sun is up for a while, the water is turned off and the ice melts from the blossoms. “Then we hope it doesn’t freeze again the next night,” said Sarah, adding they had to frost-protect two nights in a row last year on Mother’s Day weekend.
Tile drains installed under the fields after an 11-inch rain event help divert excess rainwater to ponds. “If we frost-protect two nights in a row, we can capture a good percentage of the water that sinks down to the tile line and runs back to the pond,” said Sarah. “Then we’ll have that water later to run through the drip.”
The Brouwers follow a carefully managed rotation for their strawberry crop. “The biggest change we’ve made in the past three years is using cover crops,” said Sarah, adding for every year of harvest, there’s one year of rest with a cover crop to return nutrients to the soil. “We use sorghum-sudangrass, rye, winter wheat, hairy vetch and winter peas. We also put cattle on the cover cropped land.” Sarah said studies have shown when cattle tread on the land, soil biology is activated. Cattle are moved each night, gently working organic matter into the ground. “We did that because we had an 11-inch rain event one year and a drought another year,” she said. “Both of those events destroyed the soil biology. We’re hoping that the cover cropping and livestock rotation will rejuvenate the soil and help withstand these weather events in the future.”
Because water is so critical to a good crop, each field must be prepared for both drip and overhead irrigation. Plants go in the ground in April when the soil is warm enough, and require an inch of water/week until the ground freezes in fall. The young plants require frequent hand-weeding, which Sarah and her children do every evening.
When the plants go dormant, usually in November, they’re covered with a layer of clean straw. Sarah said straw wards off fungal diseases, minimizes weeds, helps conserve water, keeps plants clean for customers and helps plants stay cool. “We haven’t needed straw in the past to keep plants cool in spring,” she said, “but with the warm temperatures the last couple of weeks, if the plants break dormancy we would have to uncover them. Then if they’re uncovered, they might blossom earlier and we’d have to frost-protect for weeks. The straw was critical in February to keep the plants insulated from the warm temperatures.” Sarah estimates they apply about six inches of straw, or a semi-load for each acre. Dan retrofitted a silage wagon which breaks up the large square bales and spreads straw over the rows.
After the winter cooling period, when the ground warms to 40 degrees (usually in April), the straw is removed. The plants come up, blossom in May, and fruit is ready in June for a three-week harvest.
As soon as harvest is over, the Brouwers mow over the rows with a lawnmower to cut off the vines. The plants still require an inch of water each week along with continued hand weeding until fall dormancy. Then the plants are covered with straw again, cool over winter, and the next spring, straw is removed, plants blossom and the second crop is harvested in June. After that crop year, if the rows aren’t too weedy or diseased, they might be kept for a third year. If perennial weeds invade, the strawberry rows are plowed under for the start of a two-season cover crop cycle. A pre-emergent applied in fall help control weeds. “We are finding that the better handle we get on the weeds, the higher quality the strawberries,” said Sarah. “Size, firmness, less disease pressure — everything is improved if we keep the weed pressure down. The plants are healthier and weeds aren’t stealing the nutrition.”
Like other growers, the Brouwers have had to deal with spotted wing drosophila (SWD), a pest which forced them to discontinue growing raspberries. They’re also avoiding late season strawberry varieties to miss the peak time for SWD. Brouwer Berries currently grows nine strawberry varieties, but Dan and Sarah are continually evaluating and experimenting with new varieties; keeping records about performance under various conditions.
The payoff for all the work is enthusiastic customers who arrive at the farm for you-pick or pre-picked berries. A ride to the field, a bucket for berries and a visit with the farm’s animals afterwards creates a memorable time for families. Sarah estimates they served about 10,000 customers in 2015, with fewer in 2016 due to lower acreage. But they’ve increased acreage and are prepared for another surge of customers this season after receiving the WCCO Viewer’s Choice Award for ‘Best of Minnesota’ Best Berry Picking.
Learn more about Brouwer Berries online at www.brouwerberries.com .

2017-03-31T10:26:07+00:00March 31, 2017|Grower Midwest|0 Comments

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