A key component to successful strawberry production is site selection and preparation. A nutritionally-healthy planting site with well-drained soil exposure to air movement is less susceptible to damage from pests and frosts. With the perennial nature of this crop, a poor site choice can create unnecessary problems for years to come. There are many factors to consider in site selection and preparation.
Site History
A well-thought-out field rotation strategy is key in site selection.
Considerations:
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Avoid a site where previous crops have included brambles, strawberries, potatoes, tomatoes, eggplant, or peppers. These crops may harbor soil pathogens such as Verticillium, Phytophthora, and nematodes, which may affect new plantings.
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Generally, the highest productivity from a strawberry field is in its first fruiting year, when it has never been used for strawberry production. The longer the period between plantings, the better they will perform. Consider setting aside land for rotation in future years because a minimum of 3–4 years should elapse between plantings on the same site.
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Knowing the herbicide application history is important. Some herbicides are persistent in the soil and can affect sensitive crops like strawberries 18, 24, and even 36 months out from the application. Knowing what product (s) were used the previous 1–2 years prior to planting is critical; 3–4 years ideal. Group 2 herbicides (ALS inhibitor), commonly used in corn, soybean, and other crops, are generally a persistent herbicide group. An example of a Group 2 herbicide used in pumpkin fields is Sandea, which indicates a plant back time of 36 months for strawberries on its label. Some products have no listing for strawberry plant back, but the possibility of carryover to a new strawberry planting exists. Without direction from the product label, it’s best to be cautious and wait 36 months. Herbicide carryover can cause crop injury ranging from minimal to complete crop loss or plant kill.
Location
In choosing field location, growers must balance several factors:
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Air drainage. Cold air, like water, runs downhill and collects in low areas or areas where trees or hedgerows obstruct airflow. These ‘frost pockets’ increase the risk of both mid-winter cold injury and spring frost damage, putting the plants under stress which can make them more susceptible to pests. Selecting a site with a gentle slope (3–4%) and good air drainage will also reduce this risk. Good air drainage will also promote faster drying
of foliage, flowers, and fruit which reduces the duration and frequency of disease infection periods. -
Slope grades. Avoid steep slopes (greater than 5%), because they are erodible and difficult to cultivate and irrigate uniformly.
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Direction. South-facing slopes tend to increase the risk of frost injury in spring because plants generally bloom earlier, and west-facing slopes present the greatest risk for winter injury because they are exposed to persistent, desiccating winds in winter.
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Water availability. Strawberry plants need a lot of water for both irrigation and frost protection. For successful berry production, the site must have access to an ample supply of high-quality water.
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Customer and personnel access. For U-Pick operations, having fields with close proximity to parking is the most efficient to manage. Wagon rides to and from the field add management considerations. If berries will be sold retail, production fields should be close to outlets to minimize time in transit.
Soil Properties
Strawberries cannot tolerate standing water or the diseases that thrive in wet conditions. If the site is too wet for strawberry production, install subsoil drainage
or plant on raised beds. In general, strawberries are tolerant of a wide range of soil types and conditions. The ideal soil for strawberry production is a well-drained, sandy loam with a pH of 6.5–6.8. Drainage and soil pH can be modified on less-than-ideal soils. In acidic, sandy soils or on calcareous soils, certain micronutrients can be deficient, so lime or sulfur may be required to adjust pH levels. Heavy clays should be avoided, but sandy soils are acceptable. Planting and cultivating strawberries are difficult in stony soils, and such soil is hard on equipment.
Nutrient Amendments
We advise taking soil samples to get a read on your pH, percentage of organic matter, and overall fertility to make changes well in advance of planting. If the organic matter level of the soil is historically low, cover crops (plowed in) or compost should be considered.
Whether you are on a matted row or plasticulture system, fertilizing prior to planting is an important first step in your strawberry nutrition program. Depending on soil type (light, medium, or heavy) we recommend 50–60 units actual nitrogen per acre with corresponding amounts of phosphorous and potassium, in a slow- release form. On matted row, this is about half of the total 90–120 units per acre seasonal requirement. For growers on plastic, fertilizer should be worked into the soil, prior to bed shaping. Matted row growers, when fertilizer is incorporated well in the root zone, can begin that process 1–2 weeks prior to planting.
Cover Crops
The many great reasons for growing cover crops include:
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Improving soil structure. Cover crops add organic matter when they are incorporated into the soil.
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Adding nitrogen to soil. Through relationships with symbiotic soil bacteria, many cover crops, particularly legumes, can add nitrogen credits to the soil.
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Suppressing weeds and disease. Cover crops compete with weeds for light, water and nutrients. Hairy vetch as a cover crop has shown to suppress some anthracnose species.
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Erosion control. Cover crops reduce water and wind erosion on all types of soil.
Choice of a cover crop should be based on what the priorities are for the cover crop benefits. If the goal is to increase nitrogen contribution to the soil, legumes are your best option. If weed control and increasing organic matter is what you want, consider non-legumes.
Weed Control
Managing weeds in strawberries can be a challenge! With these perennial crops, some weeds can become established in fields over time. Many problems can be avoided by good site selection. You should avoid sites with established perennial weeds–pastureland is not a good place to plant strawberries. If you have established perennial plants, get rid of them before planting.
It’s much easier to tackle weeds a full year before planting than to deal with them afterward. Herbicides are limited for use with strawberries, particularly through the establishment year. Effective weed control involves rotation, use of cover crops, and possible herbicide applications at least 30 days before planting. For smaller areas, repeated cultivation or covering the site with a black plastic tarp for several months can be effective. While fumigation can suppress weeds, its use is declining due to environmental concerns, cost, and availability. In certain cases, such as with severe weed pressure or soil issues, fumigation may still be justified. For best results, fumigate the soil when it is warm (above 50 ̊F), friable, and free of decomposing plant material, ideally in late summer or early fall before planting.
