Growers must use irrigation on raspberries, especially during the fruiting period, to get high-quality fruit. Water stress causes unmarketable, crumbly berries, and reduces plant growth and yield.
Establish a water source and test the water quality prior to selecting a site for your raspberry planting, to determine whether the water source is suitable for raspberries. Water that is high in certain macronutrients can alter the soil pH and limit the availability of other micronutrients. Test the irrigation water regularly and keep the soil pH between 6.0 and 6.5 to minimize nutrient management challenges.
High tunnel raspberries have greater water needs than open field raspberries because they grow larger and produce more fruit, and because of the elevated temperature in high tunnels.
Water needs also vary throughout the growing season. Be sure to keep the plants well-watered between the months of July and August, and during the fruiting period. Raspberry plants transpire up to a quarter of an inch of water each day from June through August.
How Much Water do Raspberry Plants Need for Optimal Growth?
Raspberries are a popular fruit for home gardens, prized for their sweet flavor and high nutrient content. However, growing a productive raspberry patch requires paying close attention to watering. Raspberries need sufficient moisture to thrive, but are also susceptible to root rot if overwatered. Finding the right balance is key to getting an abundant harvest. This guide covers everything you need to know about watering requirements for raspberry plants.
Water Needs of Raspberry Plants
Raspberries are shallow rooted plants, so their roots are located close to the soil surface This makes them more prone to drought stress if water is inadequate However, raspberries also dislike soggy, waterlogged soil. Standing water can lead to fungal diseases that damage roots and spread to foliage.
The ideal approach is to provide consistent moisture to raspberry plant roots without saturating the soil Aim to water deeply and infrequently, rather than frequent light sprinklings. Here are some key points on raspberry water needs
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Raspberries require about 1-1.5 inches of water per week during the growing season for optimal growth and fruiting. This can come from rainfall and/or irrigation.
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Newly planted raspberries need more frequent watering to establish deep roots. Water when the top few inches become dry.
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Established plants are fairly drought tolerant, but still need weekly irrigation if rainfall is less than 1 inch.
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Container grown raspberries and those in hot, dry climates have higher water requirements than in-ground plants.
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Too much water leaches nutrients from soil and causes root rot. Too little water leads to small fruits and drought stress.
How Often to Water Raspberry Plants
Raspberry plants don’t need water every day. You can determine watering frequency based on growth stage, weather, and soil moisture. Here are some guidelines:
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New transplants – Water every 5-7 days until well established.
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Fruiting plants – Water 1-2 times per week if rainfall is inadequate during fruit development.
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Established plants – Water weekly if less than 1 inch of rain falls.
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During drought – Deep water every 7-10 days if no rain occurs.
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In containers – Water daily or every other day depending on plant size and weather.
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After harvest – Reduce watering frequency as plants enter dormancy.
The best way to know if raspberries need irrigation is to check soil moisture. Stick your finger 1-2 inches deep – if soil is dry, it’s time to water. If still damp, hold off until drier.
How Much Water do Raspberry Plants Need?
Raspberry plants need about 1-1.5 inches of water per week for best growth and productivity. This equals 5-10 gallons per plant depending on soil type and weather conditions. Use these guidelines:
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New transplants – Water thoroughly whenever top few inches of soil are dry.
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Fruiting plants – Apply 1 inch of water 1-2 times per week if rainfall is low.
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Established plants – Water with 5-10 gallons per plant if less than 1 inch of rain that week.
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During drought – Increase amount to 10-15 gallons per plant every 7-10 days.
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Containers – Water until it flows from drainage holes. Increase frequency during hot weather.
The most accurate way to determine if plants need water is to dig down 4-6 inches and check soil moisture. If still damp, hold off on watering. Get a feel for how quickly your soil dries out to guide your watering schedule.
When to Water Raspberry Plants
Proper timing of irrigation is just as crucial as the watering volume. Here are some guidelines on when to water raspberries:
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Water early in the morning, so leaves dry quickly. This prevents fungal diseases.
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Avoid watering in the evening or at night when moisture remains on foliage for extended periods.
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Prioritize watering during flowering, fruit development, droughts, and heat waves when demand is highest.
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Reduce watering frequency after harvest as plants enter dormancy.
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Deeply water plants before winter freeze sets in to prevent desiccation damage.
Tips for Watering Raspberry Plants
Use these techniques to maximize the benefits of watering your raspberry patch:
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Add 3-4 inches of organic mulch to help retain soil moisture and reduce watering frequency. Replenish as needed.
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Install drip irrigation or soaker hoses to target water to plant roots and prevent diseases.
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Water early in the day so foliage dries quickly.
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Check soil moisture before watering to avoid oversaturating soil.
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Adjust watering frequency and volume based on plant age, weather, and container vs. in-ground growing.
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Provide wind protection and afternoon shade to reduce plant water requirements.
Signs of Under or Over Watering
Monitor your raspberry plants and adjust your irrigation practices if you notice these signs:
Under watering:
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Wilting, drooping canes.
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Dry, small fruit.
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Stunted shoots.
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Scorched, browning leaves.
Over watering:
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Fungal leaf spots.
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Root rot.
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Yellowing leaves.
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Defoliation.
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Small, pale leaves.
Adequate water is essential for growing robust, productive raspberry plants. Paying attention to their needs and environmental factors will allow you to develop an effective irrigation approach. With the right amount of water properly timed, your raspberry patch will thrive and reward you with bountiful harvests.
Installing drip irrigation Drip tape on either side of the row
Drip, also called trickle, irrigation systems deliver water uniformly and only to the raspberry plants. The slower release and the lack of unnecessary watering between rows reduces water lost via evapotranspiration. Soil type, soil water-holding capacity, and maturity of the raspberry crop determine what the irrigation schedule may look like in a given year.
Install two lines of drip tape per raspberry row. Evenly space the two tubes down the row width to ensure all roots and fruiting canes have access to moisture as they spread. A more permanent line system is generally more favorable than disposable ones as they tend to be less susceptible to rodent and insect damage.
A new planting in sandy loam soil requires 18 gallons per day per 100 feet of row. A mature planting in the same soil type requires 27 gallons per day per 100 feet of row. Increase the water rate for sandier soil, and decrease it for heavier soil.
Irrigate in frequent small amounts to keep up with increased water demand in the peak evapotranspiration months of July and August. You may need to increase weekly water application in peak summer heat.
For more information on how to set up a drip irrigation system, see Irrigation strategies for vegetables.
Exact fertilizer needs differ between farms, as they depend on the age of the planting and the type of raspberries (summer-bearing vs. fall-bearing), soil qualities, and environment (open field vs. high tunnel).
Determine nutrient requirements through soil nutrient and foliar tissue analysis.
- Conduct a soil nutrient test before planting, and every three years thereafter.
- Conduct a plant tissue analysis once raspberries reach the second year of production, and on alternate years thereafter.
Soil nutrient tests are widely used to measure the level of nutrients present in the soil. Fertilizer recommendations are generated based on research-based optimal nutrient ranges for the crop being grown. The Nutrient Management Guide for Fruit and Vegetable Crops lists the optimal ranges for each macro- and micronutrient for major specialty crops including raspberries.
Sandier soils found in some parts of Minnesota may have potassium deficiency and higher nutrient leaching.
The ideal pH range for raspberries is 5.5-7.0. More acidic soils may require amending with lime to raise the soil pH. Compost with a high pH can also be used to increase soil pH and the organic matter content of the soil. Soils with a pH above 7.0 should be amended with sulfur prior to planting.
Testing the soil 6-12 months before raspberry planting allows enough time to adjust nutrient levels and soil pH if needed. Recommendations are described in the nutrient management guide.
For more information on soil testing, visit the soil testing laboratory.
Plant tissue (foliar) analysis measures the actual nutrient concentrations in the plants and compares them to optimal ranges, thus providing a more accurate depiction of nutrient availability for raspberry production. For example, the micronutrient boron, which is critical for bud break and fruit set, is better predicted with foliar tests than soil tests.
Use foliar analysis in raspberry production in two ways: to diagnose current season nutrient issues, and to optimize annual fertilizer programs.
For routine monitoring, sample young, fully expanded leaves at the same time every year. Normal foliar analysis is done midsummer, when nutrient concentrations are the most stable.
If nutrient deficiencies are suspected, you may collect samples at any time. Submit a second sample from healthy plants, for comparison.
Collect at least 50 newly expanded primocane leaves, selecting only one leaf per primocane. The leaves should be free of disease or insect damage.
Contact your local soil analysis laboratory and follow their plant tissue collection and preparation guidelines.
Fertilizer programs are most cost-effective, sustainable, and efficient when based on soil and foliar tests and objective research.
Fertilizer can be delivered by granular broadcast or through drip irrigation. Many growers choose to apply nutrients through their drip irrigation (this is called fertigation) to save time and ensure even fertilization rates to their plants.
Fertigation may include a mix of macro- and micro-nutrients. See the table below for nitrogen recommendations. Soils with higher sand content typically require higher levels of potassium (K).
It is possible to over-fertigate. This means that excess nutrients are applied that offer little to no benefit, or when levels of certain nutrients become toxic to plant growth. Excess nitrogen, for example, leads to increased vegetative growth and a reduction of fruiting laterals due to longer internode spacing. It can even cause leaf burn symptoms. While we occasionally see claims about the benefits of routine calcium application to berries throughout the season, peer-reviewed research involving extensive in-field trials generally have not supported routine calcium application. Soil calcium levels are generally high in much of Minnesota.
There are many products on the market that claim to increase plant vigor, yield and fruit quality. Use research-based information whenever possible, and avoid products that do not provide a strong research basis to support their claims.
How to Water Raspberries : The Chef’s Garden
FAQ
Can raspberries be overwatered?
What should I do if I water Red raspberry too much/too little? An overwatered Red raspberry can start to have leaves that turn yellow, drop off and wilt.
Should you water raspberries every day?
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Arbor Day Foundationhttps://www.arborday.orgEverbearing Red Raspberry Bush Planting & Care InstructionsWatering Raspberry Bushes Water is important when young plants are being established. Water raspberries plants during the day. Give them about 1″-2″ per week du…
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OSU Extension Servicehttps://extension.oregonstate.eduGrowing Raspberries in Your Home Garden – OSU Extension ServiceNewly set plants do not have well-developed root systems, so plants can be easily stressed. Irrigate several times a week or as needed so that the root zone and…
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University of California Agriculture and Natural Resources (UCANR)https://cagardenweb.ucanr.eduGrowing Berries in Your Backyard – The California Garden WebIf raspberries are fruiting during warm weather, daily irrigation may be required. In general, apply water twice per week. Overhead irrigation promotes fruit ro…
What is the best watering system for raspberries?
The best irrigation systems are drip lines that have numerous emitters (spaced every 6 to 12 inches) that wet an entire band of soil underneath the foliage. With drip irrigation, raspberries should be watered daily for 1 to 2 hours, especially during fruiting or hot weather.
Do raspberries like wet or dry soil?
Whatever the soil, add organic matter each season. Raspberries have a shallow root system and can dry out during droughts. They need adequate water from spring through harvest usually about 1 to 1.5 inches per week.
How much water do raspberries need?
The water requirements of raspberry plants vary depending on several factors, such as the stage of growth, weather conditions, soil type, and drainage. Generally, raspberries require about 1-1.5 inches of water per week during the growing season. This estimate includes rainfall as well as supplemental watering.
How do you water a raspberry plant?
If you want to water your raspberry plants slowly and deeply, you can use a drip hose or another drip-irrigation system. Water the plants by hand at the base of the plants. When your plants start to fruit, don’t water them from above; too much water on the fruit and leaves can cause rot.
Why do raspberries need water?
Water is essential for all plants, including raspberries. It helps transport nutrients from the soil to the various parts of the plant, supports photosynthesis, and maintains turgidity in plant cells. Insufficient water can lead to stunted growth, wilting, and decreased fruit production in raspberry plants.
How do you irrigate a raspberry plant?
Hand water at the base of the plants or consider a drip hose or some other drip-irrigation method that will deliver water slowly and deeply into the soil for your raspberry plants. Avoid watering your plants from above, especially when they start to fruit; excess moisture on the fruit and foliage can cause rot.
Can You overwater raspberries?
You can definitely overwater raspberries. These shallow root plants do not like wet feet. They need good drainage to avoid getting waterlogged roots. Overly wet roots cannot absorb enough oxygen for the plants to survive. The excess moisture can also leach the soil of essential nutrients.
How do you care for a raspberry plant?
Monitor soil moisture Regularly check the soil moisture around your raspberry plants by sticking your finger into the soil. If it feels dry about an inch below the surface, it’s time to water. However, if it feels moist, hold off on watering until it becomes drier.