Cabbage

Watering at Planting and in the First Days

Abundant watering at the time of planting is mandatory. 0.5–1 liter of water is poured into each planting hole (Welbaum, 2015; Autko et al., 2012). This ensures close contact between the roots and the soil, eliminates air pockets, and initiates the rooting process. Use warm water that has been allowed to settle in the sun.

During the first week, water daily or every other day, especially in hot and windy weather. It is important not to overwater the plants—the soil should be moist but not waterlogged. Excess moisture during this period can lead to root rot and the development of diseases.

Protection from the Sun

Young plants with delicate leaf surfaces suffer from direct sunlight, especially during midday hours. Shading for the first 3–5 days after planting significantly increases survival rates. You can use:

• Lightweight row cover material (spunbond, agrofabric) on hoops,
• Burdock leaves or branches stuck into the ground next to the plant,
• Tall companion plants (corn, sunflowers) that create dappled shade.

Once the plants start growing and new leaves appear, gradually remove the cover.

Why This Works

During the establishment period, the root system is not yet capable of fully supplying the above-ground part with water. Intensive evaporation through the leaves leads to wilting—the plants lose turgor and, in severe cases, may die. Abundant watering and shading reduce the load on the roots and give them time to adapt (Kotov and Adritskaya, 2016).

What Happens to Soil Without Loosening

After each watering or rain, a dense crust forms on the soil surface. It may seem insignificant, but it actually creates serious problems:

• Restricts oxygen access to the roots. Unlike many other crops, cabbage is very sensitive to a lack of air in the root zone. With oxygen deficiency, roots absorb nutrients less efficiently, and growth slows (Autko et al., 2012).

• Increases moisture evaporation. The soil crust acts like a capillary pump, drawing water from lower layers to the surface, where it quickly evaporates. In hot weather, moisture loss through the crust can reach 30–40% of the plant's total water consumption.

• Hinders the growth of new roots. Cabbage actively develops lateral roots that require loose, well-aerated soil. A hard crust restricts their growth (Startsev, 2021).

What Loosening Provides

1. Destroys the soil crust. Breaking up the dense surface layer restores gas exchange between the soil and the atmosphere. Roots receive oxygen, and the carbon dioxide they release can escape unimpeded.

2. Conserves moisture. The disrupted topsoil layer (mulch from fine clods) prevents capillary rise and evaporation of water. After loosening, moisture is retained in the soil for 2–3 days longer (Kotov and Adritskaya, 2016).

3. Improves soil warming. Loose soil warms up faster in spring and early summer, stimulating active root system growth.

4. Controls weeds. Loosening between rows and in the root zone destroys weed seedlings at early stages, before they develop a strong root system.

How to Loosen Properly

Loosening depth depends on the timing:

• First loosening (5–7 days after planting) — depth 4–6 cm. At this stage, the root system hasn't spread much, and deep cultivation could damage young roots.
• Second and subsequent loosenings — increase depth to 8–12 cm as plants grow. The roots are stronger by then, and deeper cultivation improves their access to moisture and nutrients (Iowa State University, 2024).

Important: loosen between the rows, not directly next to the stem. Maintain a protective zone of at least 8–10 cm around the plant on each side. Cabbage roots are very delicate and easily damaged. Root injury opens the door to infections (fusarium, bacterial diseases) and slows growth.

Frequency of loosening during the season depends on soil type and weather conditions:

Agronomists recommend loosening after every heavy rain or watering, as soon as the soil has dried out slightly. On average, this means an interval of 10–14 days (Autko et al., 2012).

Best Time for Loosening

• Morning, after the dew has dried.
• Evening, when the daytime heat has subsided.

It's best to loosen after watering or rain, when the soil is optimally moist—not too dry (creates dust) and not too wet (sticks to tools).

What to Use for Loosening

For small plots, a regular hoe or cultivator is suitable. For larger areas, a power cultivator or tiller with appropriate attachments. In the early stages, when plants are still small, hand tools are convenient for more precise work near the stems.

Typical Mistakes

1. Cultivating too deep near the stem. This damages lateral roots and slows growth.

2. Loosening dry soil. In dry soil, loosening raises dust that settles on leaves and can provoke diseases.

3. Loosening immediately after a heavy rain. It's easy to damage roots in waterlogged soil, and walking on wet ground compacts it.

4. Skipping loosening after the leaves close in. Even when leaves have closed in the row, continue loosening between rows to maintain moisture and control weeds (Kotov and Adritskaya, 2016).

Why This Works

Loosening creates what is called "dry irrigation"—the top layer of soil remains dry and loose, while moisture is preserved underneath. This resembles the effect of mulching: the dry layer acts as a barrier, preventing moisture from evaporating. Thus, loosening helps plants survive dry periods without additional watering.

Furthermore, loose soil allows better air penetration, stimulating the activity of soil microorganisms that convert organic matter into forms of nutrition available to plants. This is especially important on heavy, clay soils, where without loosening, cabbage roots can literally suffocate (Welbaum, 2015).

In the next chapter, we will take a closer look at weeding—controlling weeds that rob cabbage of light, water, and nutrients, and also serve as reservoirs for diseases and pests.

Why Weeds Are So Dangerous

Weeds don't just shade the cabbage. Their negative impact is multifaceted:

1. Competition for water and nutrients. Weeds, especially those with powerful root systems (e.g., quackgrass, sow thistle), consume significant amounts of moisture and mineral nutrients. They often absorb them faster and in larger quantities than crop plants. Competition is especially fierce for nitrogen, which is critically important for building leaf mass and forming the head (Kotov and Adritskaya, 2016).

2. Competition for light. Tall weeds shade young cabbage plants. With insufficient light, cabbage stretches, the stem becomes thin, and the leaf rosette is weakly formed. This reduces plant resilience and delays maturity (Welbaum, 2015).

3. Reservoirs for diseases and pests. Many weeds from the Brassicaceae family (field mustard, shepherd's purse, wild radish, pennycress) are natural reservoirs for diseases common to cabbage: clubroot, blackleg, alternaria leaf spot, and pests like the flea beetle, diamondback moth, and aphids. Weeds serve as "transfer points" for pests, which then move to cultivated plants (Startsev, 2021).

4. Reduced ventilation. Dense weed growth impedes free air circulation near the ground. This leads to stagnant, humid air, creating favorable conditions for fungal diseases, especially in cool, rainy weather.

Critical Periods

The most dangerous period for cabbage regarding weeds is the first 4–5 weeks after transplanting, until the leaves close in the row. During this time, cabbage plants are still small and cannot compete with fast-growing weeds (Autko et al., 2012).

Experience shows that if cabbage is weeded at least once between emergence and leaf closure, yields are maintained at nearly the same level as fully weeded plots. If weeding is missed, losses can reach 30–50% (Kotov and Adritskaya, 2016).

Weed Control Methods

1. Hand weeding.

The most reliable method for small plots. It's convenient to combine weeding with loosening between rows. Remove weeds at the "white thread" stage (seedlings), before they root. When removing large weeds with strong roots, be careful not to damage the cabbage's root system—its roots are fragile and easily broken.

2. Mechanical cultivation.

On larger plots, use cultivators with weeding tines or rotary hoes. Cultivate in dry weather so pulled weeds dry out in the sun.

3. Mulching.

A layer of organic mulch (straw, mown grass, compost, sawdust) 5–8 cm thick effectively suppresses the growth of most annual weeds. This is one of the most environmentally friendly and labor-saving methods. Spread the mulch after the plants have established and the soil has warmed up, leaving clear space around the stem.

4. Herbicides.

Used mainly in commercial vegetable production. For cabbage, pre-emergence (applied to the soil before planting) and post-emergence (applied to growing plants) herbicides are approved. Use them strictly according to instructions, observing dosages, timing, and safety precautions. For home gardeners, using chemicals is not recommended due to the high risk of residual accumulation in the heads.

5. Provocative irrigation.

An effective technique for direct-sown cabbage. 7–10 days before sowing, water the bed thoroughly to stimulate mass weed germination. Then destroy the seedlings with surface loosening (without turning the soil), and only then sow the cabbage seeds. The crop is established in clean soil, giving it a developmental head start (Iowa State University, 2024).

Rules for Effective Weeding

• Start weeding as early as possible—with the appearance of the first weed seedlings.
• Remove weeds before they flower and set seed. One weed plant can produce thousands of seeds that will contaminate the soil for years.
• On the cabbage bed, don't use sharp tools too close to the stems—it's better to remove weeds by hand to avoid damaging the delicate cabbage roots.
• After weeding, it's best not to leave weeds on the bed; remove them to compost (if they haven't set seed) or to trash, so they don't reroot.
• In hot, dry weather, weed in the morning or evening so that pulled plants dry out faster and don't create a favorable environment for slugs.

Why This Works

A weed-free space allows cabbage to develop a robust root system and a large leaf canopy. Removing weeds also interrupts pest breeding cycles and reduces the infectious background, ultimately decreasing the need for pesticide applications. Regular weeding, especially combined with mulching, helps keep the area clean throughout the season (Welbaum, 2015).

In the next chapter, we will look at hilling—a technique that helps strengthen plants, promote additional root formation, and increase resistance to lodging.

What is Hilling

Hilling involves drawing moist, loose soil up to the base of the plant stem, forming a small mound (ridge). The mound's height can range from 5 to 15 cm, depending on the plant's age and the purpose of the technique (Autko et al., 2012).

Why Hill Cabbage

1. Formation of additional (adventitious) roots. Cabbage, like many other plants, has primordia of lateral roots (adventitious buds) on the stem, especially in its lower part near the root collar. When hilled with moist soil, these primordia are activated and develop into additional roots. This increases the overall absorbing surface of the root system and improves plant nutrition, especially in the second half of the growing season when the demand for water and nutrients is highest (Kotov and Adritskaya, 2016).

2. Increased resistance to lodging. Tall varieties and plants with large, heavy leaf rosettes may fall over under their own weight or due to strong winds. Hilling strengthens the stem base, making the plant more stable.

3. Improved aeration of the root zone. Hilling makes the soil around the stem looser, improving oxygen access to the roots. This is especially important on heavy, clay soils (Welbaum, 2015).

4. Additional weed control. During hilling, some weeds, especially in the root zone, get covered with soil and die.

5. Protection of the root collar from waterlogging. On wet, waterlogged plots, hilling is not recommended (see below), but on normal soils, a small mound around the stem protects the root collar from standing water during prolonged rains.

When to Hill

The timing and frequency of hilling depend on the variety's maturity:

Early varieties. Usually, one hilling is sufficient, carried out at the beginning of intensive leaf growth (15–20 days after transplanting) (Kotov and Adritskaya, 2016).

Mid-season and late varieties. Perform 2–3 hillings per season:

• first—15–20 days after transplanting,
• second—another 2–3 weeks later,
• third (if necessary)—before the leaves close in the row.

Important: perform the last hilling before the leaves close between rows. Later hilling is difficult and can damage plants (Startsev, 2021).

Best Time for Hilling

Hilling is done 2–3 days after watering or rain, when the soil is moist but not wet. Moist soil holds its shape better and clings tightly to the stem. Hilling in dry weather is useless—the soil will simply crumble. The optimal time of day is morning or evening, when there is no scorching sun (Iowa State University, 2024).

How to Hill Properly

1. Draw soil towards the stem from between the rows to form a mound 5–10 cm high (for tall varieties, up to 12–15 cm).

2. Do not cover the growing point (the top of the plant)—leave it exposed. A covered growing point can rot, especially in wet weather.

3. Use loose, fine-crumbly soil. Large clods don't adhere well to the stem and don't provide the desired effect.

4. Combine hilling with fertilization. It's convenient to apply mineral fertilizers into furrows along the edges of the rows 1–2 days before hilling. During hilling, the fertilizers mix with the soil and end up in the active root growth zone.

5. Avoid damaging roots. When hilling, try not to cut the roots. Use a hiller, hoe, or cultivator with blunt edges.

Do All Varieties Need Hilling?

Hilling is not mandatory for all varieties. Its feasibility depends on several factors:

• Variety type. Low-growing, compact, standard-type varieties with strong stems (e.g., some early hybrids) may do without hilling or with minimal hilling (once per season).

• Soil type. On light, sandy, and loamy sand soils, hilling is very beneficial as it helps retain moisture in the root zone and stimulates additional root growth. On heavy, clay soils, hilling can lead to water stagnation at the root collar and subsequent rot. On such soils, it's better to limit to loosening and mulching.

• Moisture conditions. In regions with excessive moisture (frequent rains, high water table), hilling is not recommended as it promotes moisture accumulation near the stem and development of root rots (Welbaum, 2015). Conversely, in arid regions, hilling helps preserve moisture in the root zone.

Typical Mistakes in Hilling

1. Hilling too early. If you hill immediately after transplanting, when the plants haven't established yet, it can disrupt root-to-soil contact and slow growth. Wait until the plants start growing (a new leaf appears).

2. Hilling too late. If you hill already established plants with large leaves, you can easily damage them. Furthermore, hilling after head formation begins can delay its growth.

3. Hilling too high. Covering the growing point or lower leaves leads to their rotting and weakens the plant.

4. Hilling with dry soil. Dry earth doesn't hold shape and doesn't stimulate additional root formation. Hill only with moist soil.

5. Unnecessary hilling on heavy soils. On such soils, hilling often does more harm than good.

Why This Works

Hilling stimulates the formation of adventitious roots, which significantly increase the area for absorbing water and minerals. This is especially important in the second half of the growing season when the root system of the aging plant starts to decline, but nutrient demand increases. Additionally, hilled plants hold better in the soil and suffer less from winds and downpours (Autko et al., 2012).

In practice, many experienced gardeners combine hilling with the final loosening between rows, allowing them to solve several tasks at once: destroy weeds, loosen the soil, and add soil to the stems.

In the next chapter, we will discuss mulching—an effective and low-cost way to retain moisture, suppress weeds, and stabilize soil temperature.

What is Mulching and How Does It Work

Mulching is covering the soil surface around plants with a layer of some material (organic or inorganic). This layer creates a physical barrier between the soil and the atmosphere, altering the microclimate in the root zone. The effect of mulching is based on simple physical principles:

• The mulch layer interrupts the capillaries in the topsoil through which moisture rises to the surface and evaporates. Moisture remains in the soil.
• Dark mulch (e.g., black film) absorbs solar heat and transfers it to the soil, accelerating its warming in spring.
• Light mulch (straw, hay) reflects sunlight, protecting the soil from overheating in summer heat (Welbaum, 2015).
• The mulch layer blocks light, preventing weed seeds from germinating.

Benefits of Mulching for Cabbage

1. Moisture conservation. This is the main and most valuable function of mulch for cabbage. Cabbage is a crop with very high water consumption: during active growth and head formation, one plant can consume up to 10 liters of water per day (Autko et al., 2012). Mulch reduces evaporation from the soil surface by 25–40%, significantly decreasing watering frequency and reducing the risk of roots drying out during dry periods.

2. Weed suppression. A 5–10 cm layer of mulch effectively blocks the germination of most annual weeds. Perennial rhizomatous weeds (quackgrass, sow thistle) struggle to push through the mulch and are easier to remove individually. This is especially important in the first weeks after transplanting when cabbage is still small and cannot compete with fast-growing weeds (Kotov and Adritskaya, 2016).

3. Temperature stabilization. Mulch protects roots from overheating on hot days and from cooling on cool nights. The cabbage root system is most active at soil temperatures of 15–18°C. Sharp temperature fluctuations inhibit growth and can trigger diseases like blackleg. Mulch smooths out these fluctuations (Iowa State University, 2024).

4. Preventing soil crust formation. Under mulch, the soil remains loose and air-permeable; a dense crust that hinders root respiration and the growth of new rootlets does not form. This is especially important for cabbage with its shallow root system (Startsev, 2021).

5. Improving soil structure. Organic mulch gradually decomposes, turning into humus—a valuable organic matter that improves soil structure, water permeability, and gas exchange. This makes the soil more fertile year by year.

6. Protecting produce from soiling. When growing cabbage on moist soils, mulch prevents lower leaves and the forming head from contacting wet ground, reducing the risk of fungal diseases.

What Materials to Use for Mulching

All mulching materials can be divided into two broad groups: organic and inorganic (synthetic).

How to Mulch Cabbage Properly

1. Timing of application. Apply mulch after the plants have established and grown stronger—2–3 weeks after transplanting seedlings (or after thinning when direct-sown). At this point, the soil is already well-warmed, and the mulch will work to retain heat and moisture, rather than slow down warming (Autko et al., 2012).

2. Soil preparation. Before laying mulch, remove all weeds and, if needed, loosen the topsoil layer. Ideally, water thoroughly so the soil is moist to a depth of 15–20 cm.

3. Distance from the stem. Leave a clear space 5–7 cm in diameter around the stem. This prevents rotting of the root collar and ensures air access to the plant's base. After laying the mulch, you can lightly loosen the soil in this clear circle to ensure air reaches the roots.

4. Layer thickness. For organic mulch, the optimal layer thickness is 5–10 cm. A too-thin layer is ineffective; a too-thick layer can impede gas exchange and create a favorable environment for slugs. On heavy clay soils, make the layer thinner (3–5 cm); on light sandy soils, thicker (8–10 cm) (Startsev, 2021).

5. Renewing the layer. Organic mulch settles and decomposes over time. It needs to be replenished 1–2 times per season to maintain optimal thickness.

What to Avoid

• Fresh sawdust without added nitrogen. They bind nitrogen, causing nitrogen deficiency in cabbage.
• Fresh manure. Contains high amounts of readily available nitrogen that can burn roots. Use only well-rotted manure or compost.
• Grass with seeds. This will only increase weed infestation.
• Disease-infested mulch (e.g., with late blight). Such mulch can become a source of infection.
• Mulching on very wet soil. In this case, mulch will hinder soil drying and create conditions for root rot development.
• Laying mulch right up to the stem. This is a direct path to root collar rot.

Mistakes in Mulching

• Mulching too early (immediately after planting). Prevents soil from warming up and can slow seedling growth.
• Using unsuitable materials (e.g., fresh lawn grass in hot weather—it heats up and releases heat, damaging roots).
• Not watering before mulching. If the soil is dry, mulch will only hinder moisture penetration to the roots.
• Ignoring existing weeds. Established weeds must be removed before mulching, otherwise, they will continue to grow underneath.

Why This Works

Mulching creates an optimal microclimate in the root zone: moist but not wet; cool but not cold; loose but without a crust. Cabbage roots feel comfortable and can actively absorb water and nutrients. Furthermore, mulch reduces stress from temperature fluctuations and reduces the need for watering and weeding, significantly saving the gardener's time and effort (Welbaum, 2015).

In practice, many gardeners combine mulching with other techniques: first loosening and weeding, then laying mulch. This creates ideal conditions for cabbage growth throughout the season.

In the next chapter, we will talk about protecting cabbage from temperature stress—how to protect plants from heat, late frosts, and sudden temperature swings.

How Temperature Affects Cabbage

Cabbage is a cold-resistant plant, but its tolerance strongly depends on age and development stage:

• Seeds germinate at 2–3°C, but optimally at 18–20°C.
• Seedlings and young transplants (up to 3–4 true leaves) can withstand short frosts down to –2…–3°C, but prolonged cooling or stronger frosts cause damage (Autko et al., 2012).
• Mature, hardened plants (with 5–6 or more leaves) withstand frosts down to –5…–7°C, and some late varieties down to –8…–10°C (Welbaum, 2015).
• During head formation, even brief heat above 25°C can lead to loose heads, and above 30°C can stop growth and reduce yield (Kotov and Adritskaya, 2016).

Thus, not only extreme temperatures but also their sharp fluctuations are dangerous. Swings of more than 10–15°C within a day weaken plants and make them more vulnerable to diseases.

Protecting from Heat

Signs of heat stress in cabbage:

• leaves lose turgor, become limp even with moist soil;
• leaf edges turn yellow and dry (marginal burn);
• growth slows, new leaves appear less frequently;
• head forms small and loose or doesn't form at all.

Measures to protect from overheating:

1. Regular watering. In heat, cabbage consumes more water. Water more frequently—every 2–3 days (instead of the usual 5–7 days). Increase water consumption by 20–30%. Water at the root or into furrows, avoiding water on leaves during sunny hours to prevent burns. The best time for watering is early morning or evening (after sunset), when evaporation is minimal (Iowa State University, 2024).

2. Sprinkling (cooling irrigation). In hot weather, fine mist spraying of the leaves in the evening is beneficial. This lowers air and leaf temperature, increases humidity, and stimulates photosynthesis. However, this needs to be done regularly; otherwise, the effect is short-lived. Sprinkling does not replace root watering but complements it (Autko et al., 2012).

3. Mulching. As discussed in the previous chapter, a layer of organic mulch (straw, mown grass, compost) 5–10 cm thick protects roots from overheating and preserves soil moisture. In heat, this is one of the most effective measures.

4. Shading. On the hottest days, especially in southern regions, cabbage can be shaded using lightweight row cover material (spunbond, shade net, agro-fabric) stretched over hoops. This reduces the air temperature in the root zone by 3–5°C. Shading is especially beneficial for early varieties that form heads in midsummer.

5. Choosing tolerant varieties. Some cabbage varieties and hybrids have increased heat tolerance. When selecting a variety for regions with hot summers, pay attention to this characteristic (Startsev, 2021).

Protecting from Late Frosts

Late frosts are most dangerous in the first 1–2 weeks after transplanting, when plants have not yet adapted. They can damage or kill young plants. Late varieties in autumn, on the other hand, can benefit from light frosts—they improve taste and increase storage life.

Measures to protect from frost:

1. Covering with non-woven material (spunbond, lutrasil). The simplest and most reliable method. Place the cover over hoops or directly on the plants at night, and remove in the morning (or leave if frosts are repeated). Spunbond with a density of 17–30 g/m² protects against frosts down to –3…–4°C while allowing light, water, and air to pass (Iowa State University, 2024).

2. Sprinkling. Before an expected frost, water the plants overhead (sprinkling). As water freezes on the leaf surface, it releases heat and protects tissues from damage. This method is effective for frosts down to –5°C but requires an irrigation system and is quite labor-intensive. After the frost, the ice must be washed off to avoid tissue damage (Kotov and Adritskaya, 2016).

3. Hilling. When frost threatens, hilling plants with moist soil is useful. Moist soil accumulates heat released during cooling and protects the root collar.

4. Smudging. On small plots, smoke piles can be used. Smoke creates a blanket that reduces radiative cooling of the soil. Effective for light frosts (down to –3°C).

5. Hardening seedlings. As mentioned, hardened seedlings tolerate frost much better. 1–2 weeks before transplanting, reduce watering, ventilate, and expose seedlings to outdoor air for several hours.

Protecting from Sharp Temperature Swings

Sharp temperature fluctuations (hot day—cold night) are particularly dangerous:

• during head formation: can cause cracking of heads in white cabbage (Startsev, 2021);
• in cauliflower—formation of small, "grainy" heads;
• generally weaken immunity, increasing the risk of fungal diseases.

Protective measures:

1. Mulching—as mentioned, mulch smooths out daily soil temperature fluctuations.

2. Stable watering. Soil with good moisture content heats and cools more slowly, so regular watering reduces temperature swings in the root zone.

3. Night covering. During periods of sharp swings, cover plants at night with lightweight material to retain heat.

4. Choosing regionalized varieties. Varieties adapted to local conditions better tolerate temperature fluctuations.

Summary: How to Act in Extreme Temperatures

Why This Works

Temperature stress disrupts enzyme function, slows photosynthesis and respiration, and reduces nutrient uptake. Cabbage spends energy on adapting to extreme conditions rather than on growth. Timely protective measures help plants conserve resources and direct them towards forming a quality harvest. Furthermore, by avoiding sharp swings, we reduce the risk of physiological disorders (cracking, burns, rot) and diseases (Welbaum, 2015).

In the next chapter, we will look at how controlling planting density affects ventilation, disease development, and head size. This is especially important for those growing cabbage by direct sowing in the ground or not following recommended planting schemes.

Why Proper Planting Density is So Important

Cabbage is a plant with a large leaf rosette. As it grows, it occupies a significant area. If plants are planted too close together, serious problems arise:

1. Poor ventilation. In dense plantings, air stagnates. Leaves remain wet for long periods after rain, watering, or dew. This creates ideal conditions for the development of fungal diseases: alternaria, downy mildew (peronospora), gray mold, black spot. These diseases are especially dangerous in cool, rainy weather (Welbaum, 2015).

2. Competition for light. In tight plantings, each plant tries to outgrow its neighbors and stretch upwards to get more sunlight. Stems become thin and elongated, plants weaken and are less able to resist diseases and pests. Head formation is delayed (Kotov and Adritskaya, 2016).

3. Competition for water and nutrients. The root systems of neighboring plants intertwine, leading to intense competition for moisture and mineral nutrients. Even with regular watering and fertilizing, plants may lack resources, which is especially critical during head setting and growth (Autko et al., 2012).

4. Small and loose heads. This is the most obvious consequence of overcrowding. The feeding area directly determines head size. With insufficient space, heads remain small, loose, and of low market quality. Yield per unit area decreases with overcrowding (Startsev, 2021).

5. Increased risk of pest spread. In dense plantings, it's easier for pests to move from plant to plant, and it's also harder to perform treatments with good leaf coverage.

Optimal Planting Schemes

Choosing the right planting scheme depends on three factors: the variety's maturity group, soil type, and regional climate. General recommendations for white cabbage are given in the table:

Important notes:

• For obtaining particularly large heads (for processing, sauerkraut, long-term storage), increase in-row spacing to 60–70 cm, especially for late varieties (Startsev, 2021).
• On fertile soils with good moisture, plants can be planted slightly denser; on poor soils, wider apart.
• In regions with short summers, early varieties are sometimes planted denser (25–30 cm in the row) to speed up maturation, but heads will be smaller (Iowa State University, 2024).

The rule works both ways: the larger the feeding area, the larger the head, but the later it matures. Therefore, for large heads (e.g., for sauerkraut), choose wider spacing; for early production (bunched), choose denser planting.

What to Do in Case of Overcrowding

If you sowed cabbage seeds directly in the ground or for some reason plants emerged too densely, thinning—removing excess plants—is necessary. It's a forced but necessary measure. It's better to remove some plants now than to get small, diseased heads in autumn.

When to thin: Thinning is done in two stages:

1. First stage—in the phase of 2–3 true leaves. Remove weak, distorted, damaged plants, leaving 8–10 cm between plants in the row. This gives the remaining plants more space to grow.

2. Second stage (final)—in the phase of 5–6 true leaves, when plants are clearly visible and their vigor can be assessed. Leave only the strongest, healthiest plants at the distance appropriate for the variety (see table above) (Kotov and Adritskaya, 2016).

What to do with removed plants? If they are 10–15 cm tall and have a well-developed root system, they can be:

• transplanted to another location (free spots or between rows of other crops);
• used for food as early greens (young cabbage leaves are rich in vitamins);
• added to compost (if plants are healthy).

Important: thinning is done after abundant watering, when the soil is moist. This allows removing plants with minimal damage to the root systems of the remaining ones. Carefully pull or cut plants at soil level with scissors, trying not to damage neighbors (Startsev, 2021).

How to Determine if Plantings Need Thinning

• Visually: leaves of neighboring plants close in earlier than 3–4 weeks after planting.
• Measurement: the distance between neighboring plants is less than recommended for this variety.
• Symptoms: plants appear elongated, stems thin, leaves small, lower leaves yellow (sign of light and nutrient deficiency).

Why This Works

Maintaining optimal planting density provides each plant with sufficient area to develop a robust root system and large leaf canopy. Space between plants ensures good ventilation, reducing the risk of fungal diseases and accelerating leaf drying after dew or rain. As a result, plants receive maximum light, water, and nutrients, allowing them to form dense, large, and healthy heads (Welbaum, 2015).

In commercial vegetable production, planting density is calculated to within a thousand plants per hectare to maximize marketable yield. For the home gardener, simply following the recommended intervals and thinning when necessary is enough. This simple action can significantly improve the quality and quantity of the harvest.

In the next, concluding chapter, we will discuss regular plant inspection—what and how to check in the cabbage bed to detect problems early and prevent their development.

Why Regular Inspection is So Important

Cabbage is a crop affected by many pests and diseases. At the initial stage, many problems manifest weakly and are unnoticeable to the untrained eye. Regular monitoring allows you to:

1. Detect pests at an early stage. Most caterpillars and beetles are most vulnerable at a young age. Destroying them before they cause significant damage saves effort and preserves the harvest (Kotov and Adritskaya, 2016).

2. Notice the first symptoms of diseases. Fungal and bacterial infections at the initial stage can be stopped by removing affected leaves or applying targeted treatment. Advanced diseases are difficult and sometimes impossible to cure (Welbaum, 2015).

3. Assess the effectiveness of care. Inspection shows if plants have enough water, if they are suffering from nutrient deficiencies, or if they are planted too densely.

4. Save time and resources. Localized measures are always cheaper and less labor-intensive than blanket treatments of the entire area.

What and How to Check During Inspection

Conduct the inspection carefully and systematically. It's best done in the morning after the dew has dried but before the sun gets too hot. Use a magnifying glass to check the underside of leaves—pests and their egg clusters often hide there.

How Often to Conduct Inspections

Inspection frequency depends on the growth stage and weather conditions:

• First 2–3 weeks after transplanting—inspect every 2–3 days. During this period, plants are most vulnerable, and pests (flea beetles, cabbage root fly) are particularly active.
• During active growth (from leaf closure to head formation)—inspection once every 5–7 days is sufficient.
• During head formation—inspect at least once a week, and also after each heavy rain (risk of fungal diseases) and in hot, dry weather (risk of pests).
• During peak butterfly flight periods (cabbage white, cutworm)—inspect more frequently, every 3–4 days, especially the underside of leaves for egg masses (Iowa State University, 2024).

What to Do When Problems Are Found

1. Don't panic. Most problems at an early stage are solvable.

2. Identify the cause precisely. Confirm it's a pest or disease, not a result of improper care (lack of moisture or nutrients). If in doubt, photograph the issue and seek advice from experienced gardeners or your local extension service (e.g., through partner university websites).

3. Choose a control method. On small plots, mechanical methods (handpicking caterpillars, removing affected leaves) are often sufficient. If necessary, use bio-products and, as a last resort, chemical agents, strictly following instructions.

4. Act locally. Treat only affected plants or sections of the bed, not the entire field.

5. Keep records. Record inspection dates, problems found, and measures taken. This will help in future seasons (Startsev, 2021).

Why This Works

Regular inspection is an early warning system. It allows you to spot problems at the stage of single pests or first small spots, when they can be eliminated with minimal time, effort, and resources, preventing their spread across the entire area.

Furthermore, inspection provides feedback: you see how plants are responding to your care (watering, fertilizing, cultivation). If leaves green up and grow actively after fertilization—you're doing it right. If plants wilt or yellow—you may need to adjust your routine (Kotov and Adritskaya, 2016).