Watering

1.1. Shallow Root System: A Zone of Risk

The bulk of the active, absorbing roots of raspberries lies in the upper soil layer, at a depth of only 20–40 cm (Funt & Ross, 2013; Crandall, 1994). This horizon is most susceptible to drying out in hot and windy weather, as well as to waterlogging during heavy rainfall. Unlike trees with deep taproots, raspberries cannot "mine" water from deeper soil layers. They are completely dependent on the moisture of this surface, and therefore the most unstable, layer.

This means that even a short‑term drought quickly leads to water stress, while water stagnation at the surface causes oxygen starvation and root rot (Crandall, 1994).

1.2. High Water Consumption During Critical Periods

Raspberry uses large amounts of water to form the crop and vegetative mass. Moisture loss occurs mainly through the leaves (transpiration) during photosynthesis and plant cooling. The effect of moisture deficit on yield can be traced through research data (Crandall et al., 1969, cited in Crandall, 1994). Experiments on sandy soil showed that introducing irrigation can increase raspberry yields several times (see Table 1).

Table 1. Effect of irrigation on yield of raspberry cv. 'Summer' (Crandall, 1994)

Without sufficient moisture, especially during the period of fruit set, berries form small, and the number of replacement shoots, on which next year's yield depends, is significantly reduced (Funt & Ross, 2013). A water deficit during the flower bud initiation period (immediately after harvest) is a direct threat to the next season's yield (Stanton, 2013).

1.3. Water Is Not Just Irrigation: Air and Soil

It is important to understand that water in the soil is not just a liquid. It is the medium in which nutrients dissolve, making them available to the roots. In addition, soil pores must be filled not only with water but also with air, which is necessary for root respiration. Overwatering displaces air from the soil. Roots deprived of oxygen cannot function properly, absorb water and nutrients. This leads to their dieback and increases the risk of infection by root rots, for example, Phytophthora root rot (Phytophthora spp.) (Funt & Ross, 2013). Under stagnant moisture conditions, winter hardiness also suffers, as plants do not have time to prepare for winter.

Thus, raspberry's demandingness for moisture is determined not only by its "water appetite" but also by the peculiarities of its root system, which makes the plant particularly vulnerable to both drought and overwatering. The gardener's task is to find a delicate balance, providing the soil with moisture but not allowing it to become waterlogged.

2.1. After Planting: The Establishment Period

The most critical stage for water supply is the first year of the plant's life. When dug up from the nursery, the sapling loses up to 75% or more of the active absorbing root system (Krivko et al., 2014). Root recovery and successful establishment are possible only if the soil moisture in their zone is maintained at 80‑85% of field capacity (Krivko et al., 2014). This means the soil under the young sapling must be constantly moist, but not wet.

• Goal: Create optimal conditions for the growth of new absorbing rootlets.
• Practice: Watering should be frequent but not abundant, so that water does not stagnate. In the first weeks after planting, watering may be required 1‑2 times a week, depending on the weather. Watering into a planting hole is one of the best methods for novice gardeners. In commercial orchards, in the planting year, furrow irrigation on one or both sides of the row is often used (Krivko et al., 2014).

2.2. Shoot Growth (Spring – Early Summer)

Spring growth of replacement shoots (primordia) is key to forming the framework of the future crop. If plants experience moisture deficit during this period, shoots grow short, thin, and less productive (Stanton, 2013; Funt & Ross, 2013).

• Goal: Ensure active growth of vegetative mass and the initiation of many fruit buds.
• Practice: Monitor soil moisture and do not allow it to dry out. At this time of year, natural precipitation is usually sufficient, but in dry springs, watering is mandatory. The first watering in a young orchard is often given during the period of intensive leaf and shoot growth (in May) (Krivko et al., 2014).

2.3. Flowering and Fruit Set

This stage is one of the most critical in terms of fruit quality. As Westwood (1993) notes, fruits grow mainly due to water that enters them at night. Daytime water stress caused by a lack of moisture in the soil causes the plant to take water from the fruit, slowing or stopping their growth. This is especially relevant at the flowering stage and immediately after, when active cell division in the ovary occurs.

• Goal: Ensure normal fertilization and ovary growth, prevent abscission.
• Practice: Watering during this period must be regular to maintain a stable moisture level. A water deficit during flowering and fruit set is a direct cause of small, "lopsided" berries and reduced overall yield. Studies on pears have shown that even in the absence of visible wilting, when soil moisture drops below 50% of field capacity, fruit growth slows down (Westwood, 1993). This rule also holds true for raspberries.

2.4. Berry Swelling (Ripening Period)

The peak of water consumption by raspberries occurs during the berry swelling period (Cameron et al., 1993, cited in Stanton, 2013). At this time, the berry actively accumulates water, sugars, and other substances. The main component of the berry is water (up to 80‑85%), so a lack of moisture in the soil during this period directly leads to a reduction in berry size, "dryness," and a decrease in marketable quality.

• Goal: Obtain large, juicy, and tasty berries.
• Practice: This is the most important time for watering. The soil in the root zone must be constantly moist. When grown under conditions where plants receive enough water, yields can increase many times over (Crandall, 1994). However, it is important not to overdo it: when using sprinkler irrigation during the berry ripening period, there is a risk of grey mould (Botrytis cinerea) (Stanton, 2013). It is better to prefer drip irrigation or furrow irrigation, which do not wet the foliage and berries.

2.5. After Fruiting: Preparing for Winter and Setting Next Year's Crop

Many novice gardeners mistakenly believe that after harvesting, raspberry watering can be stopped. This is a serious mistake. July and August are the time when differentiation (initiation) of flower buds begins on the replacement shoots that will bear fruit the following year (Stanton, 2013; Krivko et al., 2014).

• Goal: Ensure good flower bud initiation and shoot maturation for successful overwintering.
• Practice: In dry periods after harvest, watering must continue. This lays the foundation for next year's crop. However, closer to autumn, watering should be reduced and then stopped altogether, so as not to provoke late shoot growth, which reduces their winter hardiness (Crandall, 1994). In some cases, a moisture‑charging irrigation in late autumn is useful, helping roots better tolerate winter frosts, especially in regions with low‑snow winters (Krivko et al., 2014).

Summary Table of Water Requirements

3.1. Visual Methods: Spade and Fingers

This is the most accessible, but also the most experience‑demanding method. Its accuracy increases with practice and knowledge of your plot.

Soil Sampling Method ("By Eye and By Touch")

The essence of the method is to assess soil moisture in the zone of the main root mass — at a depth of 10–20 cm (Crandall, 1994; Stanton, 2013). Soil crust or a dry surface is not an indicator! The assessment is carried out in the layer where the roots are located.

Step‑by‑step instructions:

1. Take a sample: With a spade or garden auger, dig a hole 10–15 cm deep in several places on the plot (between rows or in the near‑trunk strip, so as not to damage roots).

2. Take a handful of soil from this hole and squeeze it in your fist.

3. Evaluate the result according to the following table (adapted from Crandall, 1994; Funt, 2013; Stanton, 2013):

Observing the Plant

As already mentioned, waiting for wilting is not allowed. However, there are earlier signs of water stress in raspberries:

• Loss of turgor in leaves (they become soft, slightly drooping) during the hottest part of the day — a signal that the roots cannot cope with the load.
• Slowing of young shoot growth.
• Reduction in size and "dryness" of fruit set against a background of normal weather.

But remember: these signs appear when the water deficit has already begun to affect the yield.

3.2. Instrumental Methods for Precise Control

For those who want to manage watering systematically and with minimal error, there are simple instruments.

Tensiometers

This is the most accurate and popular method for professional orchards and experienced amateurs. A tensiometer does not measure the amount of water, but the force with which the soil "pulls" water from the instrument. This force (suction pressure) directly depends on moisture: the drier the soil, the higher the reading on the scale.

• How it works: The instrument consists of a tube filled with water and a vacuum gauge. The porous tip of the tube is placed in the soil at the required depth. Through the pores, moisture from the soil and water in the instrument exchange. When the soil dries, it starts to draw water from the tensiometer, creating a vacuum that the needle indicates.
• How to use: Install tensiometers at a depth of 20–30 cm (the main root mass) and at 10–15 cm to control the surface layer. Readings are taken daily.
• When to water: For most crops, including raspberries, watering is recommended when tensiometer readings in the root zone reach 40–50 kPa (centibars) (Funt & Ross, 2013; Westwood, 1993). This corresponds to approximately 50% depletion of available water.
• Advantage: Tensiometers show the real moisture status in the root zone, not on the surface, and take into account the soil characteristics of your plot. They are easy to maintain and inexpensive.

Gypsum Blocks (Electrical Resistance)

An alternative to tensiometers for heavy, clayey soils. The principle is based on the fact that the electrical resistance between two electrodes placed in a gypsum block changes depending on its moisture content. The drier the block, the higher the resistance. These sensors are also buried in the soil and connected to a portable meter.

Modern Digital Sensors

In recent years, capacitive moisture sensors (e.g., TDR or FDR series) have been gaining popularity. They determine the dielectric permittivity of the soil, which depends on water content. Such sensors can be connected to automatic irrigation systems and transmit data to a smartphone or computer, which is especially convenient for remote monitoring (Funt & Ross, 2013).

3.3. Calculational Method: By Evaporation

For a more advanced level, there are methods based on accounting for evaporation and precipitation. This method is often used in professional farms.

Evaporation Pan Method (Class A)

Studies have shown that in summer, raspberries consume water at roughly the same rate as water evaporates from a standard evaporation pan (Crandall et al., 1969). By measuring daily evaporation from the pan, you can calculate how much water the plantation has lost.

"Check‑book Method"

This is a balance approach described by Crandall (1994). The essence is that you keep a record of all inputs (rain) and outputs (evaporation from the pan, adjusted for the crop). As soon as the balance shows that 50% of the available moisture in the soil has been used, you give an irrigation.

• Example: In your soil (loam), there is 5.6 cm (56 mm) of available water in the 1.2 m root zone. You decide to irrigate when 50% is used, i.e., 2.8 cm (28 mm). The evaporation pan shows that over the last days 2.8 cm of water has evaporated, and there has been no rain. So it's time to water! You need to apply 2.8 cm of water to replenish the full supply.

This method requires an evaporation pan and rainfall records, but it is very effective for large areas and allows for automation.

Whichever method you choose — from simply squeezing soil in your fist to using tensiometers — the main rule remains unchanged: do not wait for plants to wilt. Regular monitoring of soil moisture will allow you to apply water in time, avoid stress, and obtain a maximum yield of large and sweet berries.

4.1. Drip Irrigation

This is the most efficient and progressive irrigation method, which has become widely used in horticulture worldwide in recent decades (Krivko et al., 2014; Funt & Ross, 2013).

Essence: Water is supplied under low pressure through a system of tubes and emitters (drippers) directly to the root zone of each plant. Only a limited volume of soil — the root distribution zone — is moistened, while the inter‑rows remain dry (Krivko et al., 2014).

Main advantages:

• Water saving: Water consumption is reduced by 1.5–2 times compared to furrow irrigation (Krivko et al., 2014). Water is not wasted on evaporation from the inter‑row surface and does not run off where it is not needed.
• Minimal disease risk: Foliage and berries remain dry, which sharply reduces the risk of fungal diseases such as grey mould (Botrytis cinerea) (Stanton, 2013; Funt & Ross, 2013).
• Possibility to irrigate during harvest: Unlike sprinkler irrigation, drip irrigation can be used without fear of spoiling berries or interfering with pickers (Stanton, 2013).
• Fertigation: The drip system allows easy and precise application of soluble fertilizers directly to the root zone, increasing the efficiency of fertilising (Krivko et al., 2014).
• Independence from topography and wind: The system works effectively on slopes and in any weather.
• Reduced erosion and soil compaction: Soil is not washed away, and its structure is not disturbed by heavy machinery (Krivko et al., 2014).

Disadvantages and limitations:

• High equipment cost: The system requires initial investment in pipes, drippers, filters, and pressure regulators (Funt & Ross, 2013; Westwood, 1993). However, for small plots, inexpensive kits are available.
• Requires good water quality: Drippers easily clog with mechanical impurities (sand, silt), organic particles (algae), or hardness salts (Krivko et al., 2014). A filter (disc or screen) is mandatory, and the system must be flushed regularly.
• Maintenance complexity: Tubes and drippers can be damaged by rodents, tools, or during weeding. They need to be checked regularly (Funt & Ross, 2013).

Practical recommendations:

• Place the drip line (tape or tubing) along the row at a distance of 10–20 cm from the base of the bushes.
• Place drippers (emitters) at 30–60 cm apart, depending on soil type and plant age (Funt & Ross, 2013). On light sandy soils, the spacing should be smaller, as water spreads sideways less well than on loams.
• Use filters and regularly check the pressure in the system.

4.2. Furrow Irrigation

This method was widely used in commercial orchards in the USSR and remains popular in many farms due to its simplicity and low equipment cost (Krivko et al., 2014; Crandall, 1994).

Essence: Shallow channels (furrows) are cut in the inter‑rows, and water is run along them. It soaks through the bottom and sides of the furrow, moistening the soil in the root zone (Krivko et al., 2014).

Main advantages:

• Simplicity and availability: No complex equipment required. A shovel to cut the furrows and a water source are enough.
• Efficient wetting: With properly cut furrows, water penetrates to sufficient depth and thoroughly wets the root zone.
• Roots do not get wet: Water reaches the roots from below and from the sides, without wetting the root collar, reducing the risk of stem rot.

Disadvantages and limitations:

• Uneven wetting: Water may not reach the end of the furrow (especially on light soils) or may stagnate at the beginning, causing waterlogging (Crandall, 1994).
• Topography requirements: The plot must be relatively flat (slope no more than 0.01°) (Krivko et al., 2014). On slopes, water will run off and wash away soil.
• Labour‑intensive: Furrows need to be cut, repaired, and filled after each irrigation, requiring time and effort.
• Root damage: Repeated furrow cutting, especially in young orchards, can damage the shallow root system of raspberries (Krivko et al., 2014; Crandall, 1994).
• Not suitable for intensive orchards: In dense plantings on dwarf rootstocks, where roots occupy the entire inter‑row width, root damage during furrow cutting is unacceptable (Krivko et al., 2014).

Practical recommendations:

• In a young orchard in the planting year, cut one furrow on each side of the row at a distance of 60–70 cm from the trunk, 12–15 cm deep (Krivko et al., 2014).
• With age, increase the number of furrows. In a bearing orchard, cut 4–6 furrows in the inter‑row.
• The length of the furrow depends on soil type: on light soils — 50–100 m, on heavy soils — 100–200 m (Krivko et al., 2014).
• Distance between furrows: on heavy soils 0.8–1.0 m, on medium and light soils — 0.5–0.7 m.
• The first furrow is cut at a distance of 1.0–1.2 m from the trunk to avoid damaging roots.

4.3. Sprinkler Irrigation

One of the most common methods in professional horticulture, especially in arid regions (Westwood, 1993; Crandall, 1994; Krivko et al., 2014).

Essence: Water is sprayed over the canopy or under the canopy of the trees in the form of artificial rain using special machines or stationary systems.

Types of sprinkling:

• Over‑canopy: Water is applied from above, irrigating the entire orchard area. Sprinkler machines (e.g., DDN‑70, DDN‑100) or stationary systems are used.
• Under‑canopy: Water is sprayed under the canopy, directly above the root zone. A more economical option (Krivko et al., 2014).
• Fine‑mist sprinkling: Water is sprayed in the form of very fine droplets (100‑600 µm) to increase air humidity on hot days (above 30 °C). This helps reduce transpiration and alleviate temperature stress in plants (Krivko et al., 2014).

Advantages:

• Natural wetting: Mimics rain, evenly wetting large areas, including foliage and air.
• Cooling effect: In hot weather, sprinkling lowers the temperature of the air and leaves, which is especially important for southern regions.
• Frost protection: Stationary sprinkler systems can be used to protect flowers and ovaries from spring frosts. When water turns to ice, heat is released, and the temperature on the plant surface remains around 0 °C (Crandall, 1994; Westwood, 1993).

Disadvantages:

• Risk of fungal diseases: Wetting foliage and berries creates a favourable environment for the development of grey mould, anthracnose, and other diseases, especially in humid and cool climates (Stanton, 2013; Funt & Ross, 2013).
• High water consumption: Losses due to evaporation and wind drift can be significant.
• Wind dependence: Wind distorts the sprinkling pattern, making it uneven.
• Cannot be used during ripening: Using sprinkling during berry ripening can lead to rotting and loss of marketable appearance. Therefore, during this period, sprinkling must be stopped (Stanton, 2013; Funt & Ross, 2013).

Practical recommendations:

• In regions with high air humidity, it is better not to use sprinkling, preferring drip irrigation.
• If sprinkling is used in temperate climates, it should be done in the morning so that foliage dries before nightfall (Stanton, 2013).
• For frost protection, sprinkling must be continuous throughout the period of dangerous temperatures (Crandall, 1994).

4.4. Hand Watering (Basin / Hole Watering)

This is the simplest and most intuitive method, ideally suited for small home gardens and dacha plots, as well as for watering young saplings (Krivko et al., 2014).

Essence: Around the bush or sapling, a depression (basin, hole) is made with an earth rim, which is then filled with water. The water soaks into the soil in the near‑trunk area.

Advantages:

• Simplicity and availability: Requires no equipment other than a watering can or bucket.
• Water saving: Water is applied directly to the root zone and is not wasted on inter‑rows (Krivko et al., 2014).
• Safe for roots: With careful watering, the root system is not damaged.
• Ideal for young saplings: In the planting year, watering into holes is the best way to ensure establishment.

Disadvantages:

• Labour‑intensive: Takes a lot of time and effort, especially with a large number of bushes.
• Limited wetting volume: Only the basin area is wetted, and roots extending beyond it may experience water deficit (Krivko et al., 2014).
• Not suitable for large areas: On commercial plantations, this method is uneconomical.

Practical recommendations:

• The diameter of the basin should be about 1 m for a young tree or correspond to the crown projection of the bush (Krivko et al., 2014).
• The depth of water filling — 10–12 cm. For one watering under a raspberry bush, about 30‑40 litres of water is required (Krivko et al., 2014).
• After watering, the basin can be mulched (with humus, straw, grass) or covered with dry soil to reduce evaporation (Krivko et al., 2014).

Choosing a Method: Brief Recommendations

5.1. Mulching

This is the most effective and popular method of moisture conservation, especially for home gardens. Mulch is a layer of organic or synthetic material placed on the soil surface around plants (Crandall, 1994; Funt & Ross, 2013; Yaroslavtsev, 2003).

How it works: The mulching layer acts as a screen that interrupts the capillary rise of water from the lower soil layers to the surface, where it would evaporate. In addition, mulch protects the soil from direct sunlight, overheating, and wind, which also accelerate evaporation (Crandall, 1994; Westwood, 1993).

Why it is important: As Crandall (1994) notes, in dry summers, mulch may be the only way to conserve moisture in the surface root zone without daily watering. Research shows that when mulching materials are used, soil moisture can be maintained 10‑20% longer than on bare soil.

Types of mulch for raspberries:

Organic mulch:

• Straw, hay, mown grass: A classic and affordable option. The layer should be 8–10 cm when fresh, which settles over time to 2–3 cm (Crandall, 1994). Straw is especially good because it is light and reflects sunlight, heating the soil less.
• Humus, compost, well‑rotted manure: Besides conserving moisture, they enrich the soil with nutrients. However, be careful with doses: excess can cause excessive shoot growth (luxuriance) and reduce winter hardiness (Crandall, 1994; Krivko et al., 2014). Layer 3–5 cm.
• Sawdust, bark, wood chips: Excellent for retaining moisture and suppressing weeds. However, they decompose slowly and consume nitrogen from the soil. When using sawdust, be sure to apply additional nitrogen fertiliser (e.g., urea) at the rate of 20‑30 g per 1 m² (Yaroslavtsev, 2003).
• Peat: Holds moisture well but can acidify the soil. For raspberries, which prefer a slightly acidic reaction (pH 5.5‑6.0), this may even be beneficial.
• Mown green manures (e.g., barrier layer): Mown grass from inter‑rows can be used.

Synthetic mulch (plastic film, non‑woven material):

• Black polyethylene film: Very effective for weed control and moisture conservation, especially in young orchards. It prevents weed germination and almost completely eliminates evaporation (Yaroslavtsev, 2003; Funt & Ross, 2013).
• Disadvantages: Under the film, the soil overheats, which can negatively affect root development in hot climates. In addition, the film does not allow water to pass through, so when watering, it must be lifted or drip irrigation used under the film.
• Clear film: Used less often because it lets light through and promotes weed growth underneath. However, as Yaroslavtsev (2003) notes, if a thin layer (2–3 cm) of sawdust, peat, or loose soil is spread over the clear film, it also works effectively.
• Non‑woven covering material (spunbond, agrotex): Allows air and water to pass through but slows evaporation. Often used for weed control and moisture conservation. Dark colours are preferable.

Practical recommendations for mulching:

• The optimal thickness of an organic mulch layer in compacted form is 3–5 cm.
• Mulch is best applied in spring, when the soil has warmed up sufficiently but still retains moisture from melting snow.
• Do not place mulch right up to the raspberry stems — leave a small gap for air circulation to avoid bark rot.
• When using organic mulch, keep in mind that it gradually decomposes, so the layer needs to be replenished annually (Crandall, 1994).
• When using film in raspberry rows, it is an excellent way to isolate suckers and limit the spread of raspberries beyond the row (Yaroslavtsev, 2003).

5.2. Proper Soil Cultivation

Soil cultivation should aim to preserve its structure, which affects its water‑holding capacity.

Minimising Deep Tillage

Raspberry roots are shallow — mostly in the upper 10–20 cm of soil (Crandall, 1994). Deep digging or ploughing in inter‑rows damages roots, breaks capillaries, and promotes rapid evaporation of moisture from deeper layers.

• Why it works: When you loosen the surface layer, you interrupt the capillary rise of water. This creates a kind of mulching layer of dry soil that prevents evaporation from the lower, moister layers.
• When to loosen: Loosen the soil only when necessary (for weed control) and no deeper than 3–5 cm in the near‑trunk strip (Funt & Ross, 2013; Crandall, 1994). In inter‑rows, deep tillage is permissible, but it should be done as rarely as possible and only when the soil is sufficiently dry so as not to form an artificial crust (Crandall, 1994).

Important! As Crandall (1994) warns, cultivating wet soil with a rotary hoe can lead to the formation of an artificial "pan" (compacted horizon) at the cultivation depth, which impairs water permeability and aeration. Therefore, loosening should be done only in dry weather.

Creating a Water‑Permeable Structure

The soil must not only hold water but also allow it to pass through well. For this, it is important to maintain a high content of organic matter (humus). Organic matter improves soil structure, making it more loose and porous.

• How to do it: Apply organic fertilisers (compost, humus) under digging in autumn or spring (see section 5.1). Use green manure crops in inter‑rows, which, when decomposed, enrich the soil with organic matter.

5.3. Creating a Favourable Microclimate and Managing Inter‑rows

Moisture is lost not only from the soil but also evaporates from leaves (transpiration). Reducing transpiration losses and protecting against overheating is another way to save water.

Shading and Wind Protection

Strong wind and intense sun accelerate evaporation of water from leaf surfaces (transpiration) and from the soil surface (Crandall, 1994).

What to do:

• Windbreaks: Plant raspberries in places sheltered from the wind (e.g., near a fence, on the north side of buildings) or create windbreak strips of fast‑growing shrubs. Wind, especially dry winds, greatly dries out plants and can damage berries (Yaroslavtsev, 2003).
• Shading: In hot climates, it is useful to use light shading (e.g., special nets) or tall companion plants that create dappled shade. However, raspberries prefer sunny places, so full shade is not acceptable.

Inter‑row Management (Grassed vs. Bare Fallow)

How the inter‑rows are managed directly affects soil moisture.

• Bare fallow (clean, loose soil): Minimises competition for water because weeds are removed. However, open soil heats up strongly and quickly loses moisture through evaporation (Krivko et al., 2014).
• Grassed (lawn or perennial grasses): Grass in inter‑rows competes with raspberries for moisture and nutrients, especially during dry periods (Funt & Ross, 2013). However, it significantly reduces evaporation, protects the soil from overheating and erosion, improves soil structure, and provides good traction for machinery when working in the orchard.
• Optimal approach: Combined approach: In the rows, where the raspberry roots are, maintain a mulched or weed‑free surface (for maximum water saving and weed control). In the inter‑rows, leave grassed strips, but mow them regularly. This reduces competition for moisture while retaining all the benefits of grassing for soil structure and microclimate (Crandall, 1994; Funt & Ross, 2013).

Green Manure Crops for Inter‑rows

Besides permanent grassing, you can use green manure crops (temporary, e.g., winter rye, mustard, phacelia), which are sown after harvest. They grow quickly, produce green mass, which is then incorporated into the soil as organic fertiliser. This helps conserve moisture in autumn, improves soil structure, and increases its water‑holding capacity (Crandall, 1994; Krivko et al., 2014).

Summary Table of Moisture Conservation Methods

Combining these methods will allow you to significantly reduce the need for watering, save water and effort, and most importantly — create stable and comfortable conditions for raspberry growth and fruiting even during dry periods.

6.1. Mistake: Watering Only When Plants Begin to Wilt

This is the most common and dangerous mistake. By the time leaves lose turgor (become limp), the yield has already suffered losses. Fruit growth slowdown begins much earlier than visual signs of stress (Crandall, 1994; Westwood, 1993).

Why it works: The plant perceives moisture deficit as a signal to conserve resources. It closes stomata on leaves to reduce evaporation, which automatically stops photosynthesis and nutrient delivery to berries. Fruit growth stops. By waiting for wilting, you have already lost part of the potential yield, and it will be impossible to recover it.

Solution: Use the methods for determining the need for watering described in Chapter 3. Regularly check soil moisture in the root zone (at a depth of 10‑20 cm), without waiting for wilting. Focus on soil condition, not the appearance of leaves.

6.2. Mistake: Frequent but Shallow Watering

Many gardeners water raspberries frequently but lightly, wetting only the top 5‑10 cm of soil.

Why it is bad: Although the raspberry root system is shallow, the bulk of it is concentrated at a depth of 20‑40 cm (Crandall, 1994; Funt & Ross, 2013). Shallow watering does not deliver water to the main roots. As a result:

• Roots are forced to "run" after moisture towards the surface, making the plant even more vulnerable to drought.
• Moisture quickly evaporates from the soil surface, especially in hot weather.
• This promotes weed growth in the surface layer, which competes with raspberries.

Solution: Water less often but more deeply. Water should penetrate the soil to a depth of at least 30 cm (Stanton, 2013). With hand watering, you need to pour 30‑40 litres of water under a raspberry bush at one time (Krivko et al., 2014). Check the depth of wetting: a few hours after watering, dig a hole and see how deep the water has penetrated.

6.3. Mistake: Sprinkler Irrigation During Flowering and Ripening

Using sprinklers during flowering and especially berry swelling is another common mistake, particularly in humid climates (Stanton, 2013; Funt & Ross, 2013).

Why it is bad:

• Grey mould (Botrytis cinerea): Water landing on flower petals and berries creates ideal conditions for the development of this dangerous fungal disease, especially if after watering the weather is damp and cool (Stanton, 2013; Funt & Ross, 2013).
• Deterioration of berry quality: Wet berries spoil faster, become watery, and lose sugar content.
• Pollen wash‑off: Water can wash pollen from flowers, impairing pollination.

Solution: During flowering and berry ripening, use only drip irrigation or furrow irrigation. These methods deliver water directly to the roots without wetting the above‑ground parts. If you are forced to use sprinkling, do it early in the morning so that foliage dries before nightfall, and only as a last resort (Stanton, 2013).

6.4. Mistake: Stopping Watering Immediately After Harvest

Many gardeners believe that once berries are picked, raspberries no longer need watering. This is a serious misconception.

Why it is bad: July – August is a critical period when flower buds are initiated on replacement shoots, which will produce next year's crop (Stanton, 2013; Krivko et al., 2014). A lack of moisture at this time leads to few buds being formed, and they are weak. The following year's yield will be poor, even if the shoots overwinter well.

Solution: After harvest, watering must continue throughout the summer. Reduce it only closer to autumn (September) to avoid stimulating late shoot growth, which reduces winter hardiness (Crandall, 1994). Post‑harvest watering is an investment in next year's crop.

6.5. Mistake: Ignoring Soil Type

All soils hold and release water differently, and this directly affects the watering schedule (Westwood, 1993; Funt & Ross, 2013; Stanton, 2013).

Why it matters:

• Sandy and sandy loam soils: Hold very little water (see Table in Chapter 3). Water quickly drains down, and the soil dries out. Require more frequent watering, but with smaller amounts, so that water does not go too deep beyond the root zone.
• Clay and loam soils: Hold a lot of water, but it infiltrates slowly. Watering here should be less frequent but more abundant. It is important not to over‑water to avoid stagnation.
• Heavy soils with poor drainage: Very dangerous for raspberries. Overwatering displaces air from the soil, roots suffocate and die from root rots (Phytophthora) (Funt & Ross, 2013).

Solution: Before developing a watering schedule, study the soil type on your plot (you can do a simple test with moist soil by rolling it into a rope). For sandy soils, increase watering frequency; for clay soils, ensure good drainage and use mulching. On heavy soils and where the water table is high, furrow irrigation or flood irrigation is categorically not recommended. The best choice is drip irrigation or watering into basins to control the volume of water.

6.6. Mistake: Using Cold Water from a Well

Watering with ice‑cold water from a deep well or artesian borehole is a stress for the root system, especially in hot weather (Krivko et al., 2014).

Why it is bad: A sharp temperature difference (hot soil and icy water) shocks the roots. Absorbing rootlets may stop functioning, and the plant will not receive moisture even if the soil is wet. This slows growth and can lead to fruit drop.

Solution: If possible, use water from open reservoirs, ponds, or storage tanks that has warmed up in the sun for irrigation. If well water is used, let it settle and warm up in a barrel during the day. Water in the evening, when the soil has cooled slightly, so that the temperature contrast is not so sharp.

6.7. Mistake: Ignoring Water Quality

This is especially important when using drip irrigation, but is also relevant for other methods (Westwood, 1993; Funt & Ross, 2013).

Why it is bad:

• Mechanical impurities (sand, silt, algae): Clog drippers, filters, and even soil pores, reducing irrigation efficiency.
• Salts (high mineralisation): Water with a high salt content (especially in arid regions) can salinise the soil, making it unsuitable for raspberries. Plants will suffer from "physiological drought" — roots cannot absorb water due to high osmotic pressure in the soil solution.
• Alkaline water (high pH): Can cause chlorosis (yellowing of leaves due to iron deficiency).

Solution: For drip irrigation, always use filters (disc or screen). Regularly check and clean them (Krivko et al., 2014). When using water from questionable sources, have it chemically analysed in an agrochemical laboratory. With high mineralisation, use drip irrigation with large application rates to leach salts, or consider building a storage pond to mix water from different sources.

6.8. Mistake: Overwatering

This is the flip side of the problem, no less dangerous than drought (Funt & Ross, 2013; Crandall, 1994).

Why it is bad: Over‑watered soil displaces oxygen from pores, roots cannot breathe. This leads to:

• Death of absorbing roots.
• Development of root rots (especially dangerous is Phytophthora root rot).
• Reduced winter hardiness: wet, "luxuriant" shoots do not have time to mature before winter and are damaged by frost (Crandall, 1994; Funt & Ross, 2013).

Solution: Water only when truly necessary (see Chapter 3). Ensure that there is no water stagnation on the plot. On heavy soils, use raised beds (raised ridges) or drainage. Signs of overwatering: yellowing leaves, stunted growth, wilting even when soil is wet, unpleasant "musty" smell from the ground.

Conclusion on Watering Mistakes:

Proper watering of raspberries is a balance between excess and deficiency of moisture. The key to success is systematic monitoring and understanding the plant's needs at each stage of its development. By avoiding these typical mistakes, you can significantly increase yield, improve berry quality, and extend the life of your raspberry plantation.