Zucchini, squash

The Cucurbit Family (Cucurbitaceae)

All of these plants belong to the large and diverse family Cucurbitaceae (Cucurbitaceae). This family comprises approximately 118 genera and 825 species (Wehner et al., 2020; Pessarakli, 2016). Most of them are herbaceous vines distributed across tropical and subtropical regions of the world.

In addition to zucchini, this family includes the well-known cucumber (Cucumis sativus), melon (Cucumis melo), watermelon (Citrullus lanatus), as well as pumpkins and various gourds (bottle gourd, luffa, etc.). They all share similar structural features but are clearly distinguished at the genus and species levels.

The Genus Cucurbita L.

The genus Cucurbita represents the "American branch" of the family. All of its species originate from the New World. Within this genus, five major cultivated species are recognized (Pessarakli, 2016; Wehner et al., 2020):

1. Cucurbita pepo L. — the most well-known and diverse species. This includes all zucchinis, courgettes, and pattypan squashes, as well as many ornamental gourds, some table pumpkins (acorn squash), and certain pie pumpkin varieties.

2. Cucurbita maxima Duch. — large-fruited pumpkins: giant varieties (record-breakers in weight), as well as Hubbard, Buttercup, and others.

3. Cucurbita moschata Duch. — butternut squashes, including the well-known butternut squash and some canning varieties.

4. Cucurbita argyrosperma Huber (formerly C. mixta) — cultivated mainly in Mexico and Central America for its seeds (pepitas).

5. Cucurbita ficifolia Bouché — fig-leaf gourd, used as rootstock and for making sweets.

It is the species Cucurbita pepo that is of greatest interest to us.

The Species Cucurbita pepo — A Center of Diversity

Cucurbita pepo is a unique species. Among all cultivated plants, it perhaps possesses the greatest diversity of fruit shapes, sizes, and colors. This is the result of centuries of breeding, conducted both in America and, particularly actively, in Europe.

A key point for gardeners: all representatives of C. pepo freely cross-pollinate with each other. This means that zucchinis, courgettes, and pattypan squashes growing nearby can intercross. The result of this cross-pollination will affect not the current year's harvest, but the fruits and seeds you collect for planting in the following season (Prohens & Nuez, 2008). This is worth remembering if you plan to save your own seeds.

Subspecies and Cultivar Groups

Within C. pepo, botanists and breeders distinguish two main subspecies and several cultivar groups, which correspond to the familiar culinary and gardening categories (Paris, 2000; Prohens & Nuez, 2008):

• Subspecies *pepo: includes most of the familiar table forms. This subspecies includes zucchinis, courgettes, vegetable marrows, as well as round and decorative gourds*.
• Subspecies texana (formerly ovifera): includes forms that most often originate from the eastern United States. This includes pattypan squashes (scallops), as well as crookneck varieties and acorn squash.

The differences between these groups are not only external but also genetic, although they do not present an insurmountable barrier to cross-breeding.

Why Is This Important for the Gardener?

1. Understanding varieties. The choice is vast: from bush zucchinis to vining forms, from yellow to green, from round pattypans to long courgettes. All are the same species, and their cultivation techniques are practically identical.

2. Crop rotation. Cucurbit crops (cucumber, pumpkin, zucchini, watermelon) should not be planted in the same spot year after year. This helps prevent the buildup of soil-borne diseases (Nonnecke, 1989). Since they are all related, this rule applies equally strictly to all of them.

3. Seed saving. If you want to obtain a "pure" variety for the next year, zucchinis, courgettes, and pattypans should be planted either at a considerable distance from each other (several hundred meters for complete isolation) or you should perform artificial pollination by isolating the flowers. Otherwise, their seeds will produce hybrids that may not match the parental forms (Rubatzky & Yamaguchi, 1997).

In the next chapter, we will examine the plant's botanical structure in detail: how its roots, leaves, flowers are arranged, and how the fruit develops.

Root System

The roots of zucchini and pattypan squash are taproots, but highly branched. They penetrate the soil to a depth of 1.5–2 meters, however, the bulk of the roots (up to 80–90%) are located in the upper topsoil layer (20–40 cm) (Nonnecke, 1989; Kotov & Adritskaya, 2016).

What this means for the gardener:

• Cultivation. Roots need oxygen. Therefore, regular shallow loosening of the soil after watering or rain (until the plants close their leaves) is beneficial.
• Watering. Despite the deep taproot, the plant primarily feeds from the upper layer. This means watering should be regular but not too abundant, to prevent waterlogging.
• Fertilization. Fertilizers are best applied in the zone where the majority of absorbing roots are located — that is, near the surface, but at some distance from the stem (to avoid burning).

Stem

In nature, Cucurbita pepo is a vining plant. However, modern varieties of zucchini, courgette, and pattypan squash are bush forms, with an erect, thick, stiffly hairy stem and very short internodes (Prohens & Nuez, 2008). The length of the main stem usually does not exceed 0.5–1 meter. Lateral shoots (vines) are few or absent.

Advantages of the bush form:

• Compactness — saving space in the garden bed.
• Ease of care (weeding, loosening, harvesting).
• Earlier and more uniform fruiting, as nutrients are directed not toward excessive foliage growth but toward fruit formation (Lebedeva, 1987; Kotov & Adritskaya, 2016).

Some older varieties or those intended for southern regions have semi-vining forms, but for most gardeners, bush-type hybrids and varieties are preferable.

Leaves

Zucchini leaves are large, five-lobed, stiff, with prickly hairs. They sit on long petioles. A notable feature: in courgettes (zucchinis), the pubescence of leaves and petioles may be significantly weaker or sometimes completely absent (Nonnecke, 1989; Lebedeva, 1987). Some varieties have white or silvery spots on the leaves — this is not a disease but a varietal trait that helps the plant reflect excess sunlight (Autko et al., 2012).

The leaves create dense shade, helping to retain soil moisture and suppress weed growth. However, in dense plantings, this same characteristic can lead to fungal diseases due to reduced air circulation.

Flowers

Zucchini is a monoecious and unisexual plant. This means that each plant bears both male and female flowers. They are easily distinguishable (Rubatzky & Yamaguchi, 1997; Prohens & Nuez, 2008):

• Male flowers — grow on long, thin pedicels. In their center, a stamen with pollen is visible. They often appear first and in greater numbers.
• Female flowers — are distinguished by the presence of an ovary at the base of the flower. Upon closer inspection, this ovary has the shape of a tiny zucchini (or pattypan, depending on the variety). It is from this that the fruit will develop after pollination.

Important flowering features:

• Flowers open early in the morning and live for only one day (about 4–6 hours) (Wehner et al., 2020).
• Zucchini is a cross-pollinated plant. Fruit set requires the transfer of pollen from a male flower to a female one. This is done by insects, mainly bees and bumblebees.
• In cool or rainy weather, insect activity decreases, which can lead to poor fruit set.
• Early varieties have more female flowers, ensuring an earlier harvest (Lebedeva, 1987; Autko et al., 2012).

What the gardener can do: if bees are scarce, you can perform artificial pollination. To do this, pick a male flower, remove the petals, and touch the anthers to the stigma of the female flower's pistil. This guarantees fruit set.

Fruit

The fruit of the zucchini is a pepo (a berry-like fruit), characteristic of the entire Cucurbitaceae family. At technical maturity (i.e., the stage at which we eat these vegetables), the fruits of zucchini and courgettes have an elongated cylindrical shape. Color varies from white and cream to dark green, striped, or yellow. The pattypan squash has a saucer- or disc-shaped fruit with scalloped edges (Nonnecke, 1989; Prohens & Nuez, 2008).

The key difference between zucchini and courgette is that courgettes (zucchinis) typically have a darker color (dark green or striped) and denser, crisper flesh that does not overgrow as quickly as traditional white-fruited zucchinis (Lebedeva, 1987).

The fruits grow very quickly — under favorable conditions, they reach marketable size within 2–5 days from fruit set. Therefore, they should be harvested regularly, preventing them from overgrowing. If you leave one large fruit on the plant, it will "slow down" the formation of new fruit sets (Nonnecke, 1989; Rubatzky & Yamaguchi, 1997).

Seeds

The seeds of zucchinis, courgettes, and pattypans are large, white or cream-colored, ovoid, with a prominent hilum. They retain germination capacity for up to 6–8 years, although seeds that are 2–3 years old produce the highest yields (Lebedeva, 1987; Kasykina & Kudin, 2018).

When seeds mature, the fruit becomes hard-skinned and changes color to yellow or orange. Such fruits can be stored and used to obtain seeds, but they are no longer suitable for eating due to the coarse fibrous flesh (Nonnecke, 1989).

Tip for the gardener: if you want to collect your own seeds, leave 1–2 of the most typical fruits on the plant until full biological maturity. Wait until they turn bright yellow or orange, then harvest them and leave them to ripen in a dry, warm place for another 2–3 weeks. After that, the seeds can be extracted, washed, dried, and stored.

Temperature Requirements

Zucchinis and pattypans are heat-loving plants. Their seeds begin to germinate at soil temperatures of +8…+10 °C, but the optimum for rapid and uniform emergence is +18…+25 °C (Nonnecke, 1989; Kotov & Adritskaya, 2016). At soil temperatures below +10 °C, seeds may rot, and seedlings emerge very slowly.

The plants do not tolerate frost. Even a brief drop in temperature to –1…–2 °C can kill young plants or severely damage leaves. Mature plants may stop developing during autumn cold snaps down to +4…+5 °C, and fruit set ceases (Rubatzky & Yamaguchi, 1997; Wehner et al., 2020).

Optimal temperature ranges for growth and fruiting:

• Daytime: +20…+28 °C — the most comfortable temperature for active growth, flowering, and fruit set.
• Nighttime: +14…+18 °C — cooler nights promote better fruit set and reduce the risk of fungal diseases.
• Critical threshold: temperatures above +32…+35 °C combined with dry air lead to flower and fruit drop, reduce pollen quality, and impair pollination (Nonnecke, 1989).

What this means for the gardener:

• In regions with cool climates (northern areas, Siberia, much of the Non-Black Earth region), it is strongly recommended to use the transplant method and temporary film covers (hoops with agrofabric or plastic film) at the beginning of the season (Lebedeva, 1987; Autko et al., 2012).
• The timing for sowing seeds directly into the ground should be such that the soil at a depth of 10 cm has warmed to at least +10…+12 °C and the threat of late frosts has passed.
• In hot climates (southern regions), it is important to provide regular watering and, if possible, light shading during the hottest hours.

Moisture Requirements

Zucchini is a moisture-loving plant. This is due to its rapid growth, large leaf mass, and intensive fruiting (Nonnecke, 1989). However, it is important to distinguish between soil moisture and air humidity requirements.

• Soil moisture: although the root system of zucchini is powerful, it absorbs the majority of water from the topsoil layer. The optimal soil moisture is 70–80% of field capacity (Kotov & Adritskaya, 2016). Lack of moisture leads to wilting of leaves, dropping of fruit sets, and reduced yield. Excessive waterlogging and stagnant water are dangerous: roots rot, and fungal diseases develop.
• Air humidity: zucchini and pattypan prefer moderate air humidity (60–70%). Too dry air (especially at high temperatures) impairs pollination and promotes flower drop. Too high humidity (above 80%) creates a favorable environment for powdery mildew and other fungal infections (Nonnecke, 1989; Rubatzky & Yamaguchi, 1997).

Practical watering recommendations:

• Watering should be regular but not excessive. It is best to water at the base, trying not to wet the leaves to avoid sunburn and disease development.
• In hot, dry weather, water generously 2–3 times a week. In cool, rainy weather, reduce watering.
• Mulching the soil (with peat, compost, straw, black plastic) helps retain moisture, prevents crust formation, and protects roots from overheating (Lebedeva, 1987).
• During the peak flowering and fruit-setting period, watering is especially important. Lack of moisture during this time severely reduces yield.

Light Requirements

Zucchinis and pattypans are short-day, light-loving plants. This means that for abundant production of female flowers and fruiting, they require intense illumination, but the optimal day length is 12–14 hours (Rubatzky & Yamaguchi, 1997; Kotov & Adritskaya, 2016).

• Under short-day conditions (early in the growing season, in spring), plants form more female flowers and begin fruiting earlier.
• Under long-day conditions (summer, northern regions), there may be excessive vegetative growth (leaves and vines) at the expense of fruiting.
• Shaded areas are categorically unsuitable for zucchini. Even light shade (from a fence, tall plants) leads to stem elongation, reduced fruit set, and poorer fruit quality (Nonnecke, 1989).

What the gardener should do:

• Choose the sunniest and most open areas for planting, protected from cold northern winds.
• Avoid overcrowding: follow recommended spacing (usually 70×70 cm or 70×100 cm for bush forms, and wider row spacing for vining forms).
• Remove lower, aging leaves in a timely manner to improve light penetration and air circulation.

Soil Requirements

Zucchinis and pattypans are not demanding regarding soil type, but for high yields and good quality, they prefer light, fertile, well-drained soils with neutral or slightly alkaline reaction (pH 6.5–7.5) (Nonnecke, 1989; Lebedeva, 1987).

Optimal soils:

• Loamy and sandy loam soils rich in organic matter (humus).
• Chernozems, well-cultivated.
• Drained peatlands after liming.
• Heavy clay and acidic soils (pH below 5.5) are unsuitable: roots develop poorly, and plants often suffer from diseases (Kotov & Adritskaya, 2016).

Soil preparation:

• Best preceding crops: potatoes, cabbage, onions, legumes, root vegetables.
• Zucchinis and pattypans should not be planted after cucumbers, pumpkins, watermelons, and other cucurbits, as this promotes the buildup of specific soil-borne diseases (Nonnecke, 1989).
• In autumn, the plot is dug to a depth of 25–30 cm and organic fertilizers are applied: 4–6 kg/m² of well-rotted manure or compost. Acidic soils should be limed (Lebedeva, 1987; Autko et al., 2012).
• In spring (1–2 weeks before planting), the soil is loosened, mineral fertilizers (superphosphate and potassium salt) and, if necessary, wood ash are applied.

Why this matters: soil well-enriched with organic matter and having a neutral pH ensures a quick start, active root system development, and consequently, a high yield. In overly compacted or acidic soil, roots poorly absorb nutrients, even when they are applied.

In the next chapter, we will examine the physiology of zucchini: how it develops from seed to fruiting, what "technical maturity" means, and why it is so important to harvest on time.

Life Cycle: From Seed to Fruit

Zucchini, like all representatives of Cucurbita pepo, is an annual plant. Its entire life cycle is completed within a single growing season. From sowing to the first harvest takes 40 to 60 days, depending on the variety and weather conditions (Lebedeva, 1987; Nonnecke, 1989).

Technical vs. Biological Maturity: What's the Difference?

For the gardener, this is a key distinction.

Technical maturity is the stage when the fruit has reached the size characteristic of the variety, but the seeds inside are still soft, underdeveloped, and the skin is soft (easily pierced with a fingernail). It is at this stage that zucchini, courgette, and pattypan squash are eaten (Nonnecke, 1989; Lebedeva, 1987). For most varieties, technical maturity occurs 8–12 days after pollination.

Biological (physiological) maturity is the full ripening of the fruit and seeds. Externally, this is manifested by:

• Hardening of the skin, which becomes tough like that of a pumpkin.
• Color change — the fruit turns yellow, orange, or creamy beige.
• Coarsening of the flesh, which becomes fibrous, dry, or bitter (Kotov & Adritskaya, 2016).

At biological maturity, the fruits are inedible fresh but can be stored for several months and used for seed production.

Why You Should Not Allow Fruit Overgrowth

This is one of the most important cultivation practices, based on plant physiology.

How it works:

Developing fruits are powerful consumers of assimilates (photosynthates) produced by the leaves. If you allow a fruit to overgrow (approach biological maturity or just become very large), it begins to dominate and suppresses the formation of new female flowers and fruit sets (Nonnecke, 1989; Rubatzky & Yamaguchi, 1997). The plant "decides" that it only needs one or two fruits for seed maturation and does not need to continue fruiting. As a result, total yield drops sharply.

What to do:

• Harvest fruits regularly, every 2–4 days (at peak production, every other day).
• Cut the fruits with part of the peduncle using a sharp knife (do not tear or twist them off, to avoid damaging the stem and the plant).
• Remove all overgrown, misshapen, and rotting fruits from the plant, even if you do not plan to eat them. They still consume the plant's energy (Lebedeva, 1987).

Regular harvesting not only provides you with young, tasty fruits but also stimulates the plant to produce more and more new fruit sets, thereby extending the fruiting period right up to the first frost.

Pollination Features

Since flowers live for only one day, it is very important that there are pollinating insects on the site during the morning hours (when they are open).

Pollinating insects. The main pollinators of zucchini are bees, bumblebees, and some solitary bee species (Wehner et al., 2020).

Pollination problems. In cool, rainy, or excessively hot weather, insect activity declines. Poor pollination can also be due to a shortage of male flowers (in some hybrids) or because female flowers appear before male ones.

Artificial pollination. If you notice that fruit sets are yellowing and dropping without developing into fruits, you can perform hand pollination (Nonnecke, 1989; Prohens & Nuez, 2008). To do this:

1. Pick a male flower.

2. Remove all petals, leaving only the stamen with pollen.

3. Gently touch the anthers to the stigma of the female flower's pistil (the stigma should be sticky and moist). You can use a brush, but using the flower is easier.

4. It is advisable to do this on several female flowers.

Parthenocarpy in Some Hybrids

Some modern zucchini and courgette hybrids have the ability to set fruit without pollination — a phenomenon called parthenocarpy (Rubatzky & Yamaguchi, 1997; Wehner et al., 2020). Such hybrids (often noted in the description) are ideal for growing in greenhouses, tunnels, and in regions where there are few bees or where the weather is frequently poor. Fruits of parthenocarpic hybrids typically have dense flesh and contain no seeds or only underdeveloped seed remnants. However, such hybrids are often more demanding in terms of nutrition and moisture.

In the next chapter, we will discuss why it is worth growing these crops — their chemical composition, nutritional value, and health benefits.

General Chemical Composition

The flesh of zucchini, courgette, and pattypan squash consists of more than 90% water (Nonnecke, 1989). This accounts for their low calorie content and refreshing properties. Dry matter averages 5–8% and varies depending on the variety, fruit age, and growing conditions. The younger the fruit, the more water it contains and the more tender it is (Lebedeva, 1987; Rubatzky & Yamaguchi, 1997).

Data are from: Nonnecke, 1989; Watt et al., 1963; Kotov & Adritskaya, 2016.

An important feature: the content of dry matter and sugars is usually higher in courgettes (zucchinis) than in traditional white-fruited zucchinis, making their flesh denser and less watery. This is why courgettes are better suited for frying, baking, and stewing — they hold their shape and do not fall apart (Lebedeva, 1987).

Vitamin Composition

Zucchini and pattypan are not champions in vitamin content, but they provide the body with important compounds, especially when fresh. The most significant vitamins are:

• Vitamin C (ascorbic acid): 10–20 mg per 100 g of raw flesh (Nonnecke, 1989). This is about 15–20% of the daily requirement. Some vitamin C is destroyed by heat, so young zucchinis and courgettes are best eaten fresh (in salads).
• B vitamins (B₁, B₂, B₆): present in small but noticeable amounts (Watt et al., 1963). They are involved in metabolism and maintaining the nervous system.
• Vitamin PP (niacin): up to 0.5–0.7 mg per 100 g, comparable to other popular vegetables.
• Carotenoids (provitamin A): particularly important in green courgettes and yellow fruits. They contain lutein and zeaxanthin — antioxidants that protect the eyes from age-related changes and support visual acuity (Rubatzky & Yamaguchi, 1997). White-fruited zucchinis contain significantly fewer carotenoids.

Mineral Composition

Zucchinis and pattypans are a good source of potassium, magnesium, phosphorus, and calcium, as well as trace elements: iron, zinc, manganese, and copper (Watt et al., 1963; Nonnecke, 1989).

• Potassium (K): 200–250 mg per 100 g. Potassium is essential for maintaining water-salt balance, normal heart function, and muscle function. It is the high potassium content that makes zucchinis beneficial for people with cardiovascular diseases.
• Magnesium (Mg): 20–30 mg per 100 g. Involved in nervous system function and muscle contractions.
• Phosphorus (P) and calcium (Ca): 25–40 mg per 100 g. These elements are important for bones and teeth.
• Iron (Fe): 0.5–0.8 mg per 100 g. Although not a record amount, iron from vegetables is well absorbed, especially in combination with vitamin C.

In pattypans, the skin contains more minerals than the flesh, so they are beneficial to eat with the skin on (when young) (Lebedeva, 1987).

Dietary Fiber (Cellulose and Pectin)

Zucchinis and pattypans contain soft, easily digestible fiber (about 1 g per 100 g), which does not irritate the gastrointestinal tract. Additionally, they contain pectin substances, which promote gentle bowel cleansing, regulate stool, and help lower blood cholesterol levels (Nonnecke, 1989). This is one of the key properties that makes these vegetables indispensable in diets for people with gastrointestinal conditions (gastritis, colitis) and for the elderly.

Caloric Content and Dietary Value

Zucchinis and pattypans are among the lowest-calorie vegetables.

• Zucchini and pattypan: about 15–20 kcal per 100 g.
• Courgette: due to its denser flesh — up to 25–30 kcal per 100 g.

Due to their low calorie content and high water content (which creates a feeling of fullness with low volume), these crops are actively used in weight-loss diets, in the nutrition of people with overweight and diabetes (Rubatzky & Yamaguchi, 1997). Their carbohydrates are mainly represented by easily digestible sugars (glucose and fructose), and starch is practically absent, making them safe for diabetics (low glycemic index).

Differences Among Different Cultivar Groups

Although the main indicators are similar, there are differences:

• Courgettes (dark green, striped, yellow varieties) contain more carotenoids, vitamin C, and potassium compared to white-fruited zucchinis. They have denser, crunchier flesh, rich in dietary fiber.
• Pattypans contain more pectin and fiber than zucchinis, due to their denser structure. They also store better when mature (Lebedeva, 1987).
• White-fruited zucchinis are the most "watery"; their flesh is tender and contains the least dry matter. They are ideal for dietary nutrition, soups, and baby purees.

Higher Nutritional Value in Mature Fruits and Seeds

In biologically mature fruits (which are no longer suitable for eating as vegetables), the content of dry matter, sugars, B vitamins, and minerals increases. The seeds are particularly valuable — they contain up to 30–40% fat (mostly unsaturated fatty acids), 20–25% protein, as well as magnesium, zinc, and vitamin E (Nonnecke, 1989; Rubatzky & Yamaguchi, 1997). So, if you are not using an overripe fruit for food, do not throw away the seeds — they can be dried, toasted, and used as a healthy and tasty snack.

What This Means for the Gardener

• If your goal is to maximize vitamins, prefer brightly colored varieties and hybrids (dark green, yellow, orange). Their concentration of beneficial compounds is higher (Rubatzky & Yamaguchi, 1997).
• For dietary nutrition, young fruits at technical maturity are better — they contain less fiber, are easier to digest, and have the lowest calorie content.
• If you are interested in obtaining seeds as a valuable product, allow 1–2 fruits to reach biological maturity and extract the seeds — this will not only give you planting material but will also add a valuable source of plant protein and fats to your diet.

In the next chapter, we will move on to practical classification: varieties and hybrids of zucchini, courgette, and pattypan squash, their main groups, and selection criteria.

7.1. Division by Cultural Groups (by Fruit Type)

This is the most obvious and familiar division, based on fruit shape and structure at technical maturity.

7.2. Classification by Maturity (Ripening Groups)

This classification is important for planning sowings and obtaining a continuous harvest conveyor.

• Ultra-early: from emergence to first harvest — 35–45 days. Very early-maturing varieties and hybrids, yielding in the shortest possible time. Suitable for regions with short summers. Examples: Rolik, Belogor F1.
• Early: 40–55 days. This is the main group, yielding early and uniformly. Most popular varieties of zucchinis and pattypans belong to this group (Nonnecke, 1989; Lebedeva, 1987). Examples: Gribovskie 37, Izyashchny, Beloplodnye.
• Mid-season: 55–70 days. Fruiting starts later but is often more prolonged. Such varieties can yield until autumn. Examples: Kuand, Pharaoh.
• Late: more than 70 days. Less common, mainly in vining forms or in varieties intended for long-term storage. In regions with short summers, they are not advisable to grow.

7.3. Classification by Growth Habit

This classification determines how much space the plant will occupy and how to care for it.

• Bush forms: stem is short, erect, with very short internodes. Lateral shoots are almost absent. Area occupied — about 0.5–1 m². This is the ideal choice for small plots, greenhouses, and dense plantings. Most modern hybrids of zucchinis and pattypans are bush types (Prohens & Nuez, 2008; Wehner et al., 2020).
• Semi-vining: stem of medium length, produces a small number of short lateral shoots. Takes up more space but is more productive. Found in some older varieties.
• Vining (long-vining): forms long, trailing vines (more than 1.5–2 m). Rarely used in home gardening but can produce very high yields on large areas (Nonnecke, 1989). They require more space and wider row spacing.

Why this matters: for greenhouses, tunnels, and small beds, choose only bush forms. For open ground, if space allows, you can try semi-vining forms, but they require more effort (pinching, shaping).

7.4. Classification by Fruit Color

Color is not just aesthetic; it also indicates the content of beneficial compounds.

• White-fruited: the mildest flavor, lowest calorie content, watery flesh. Good for dietary dishes and baby food.
• Dark green, striped: (most courgettes). Denser flesh, rich flavor, high content of carotenoids (lutein, zeaxanthin) and vitamin C. The best choice for frying and baking.
• Yellow and orange: contain significant amounts of beta-carotene (provitamin A). Very decorative. Flavor can vary from neutral to slightly sweet. Examples: Zheltoplodny, Zolotinka.
• Variegated (striped): very popular (courgette varieties Zebra, Pharaoh). In taste and beneficial compound content, they are close to dark green ones.

7.5. Classification by Intended Use

• Salad (universal): best for fresh consumption, in salads. They have tender, juicy flesh and thin skin. Examples: Izyashchny, Gribovskie 37.
• Canning (pickling, preserving): characterized by dense flesh that does not disintegrate during processing, as well as small fruit size (especially gherkins and pattypans for whole-fruit canning). Examples: Belogor F1, many hybrids for canning.
• Universal: suitable both for fresh consumption and for all types of processing. Most modern hybrids belong to this group (Lebedeva, 1987).

7.6. Open Ground vs. Protected Ground

Another division — by the type of cultivation.

• For open ground: varieties and hybrids with high resistance to adverse weather conditions (temperature fluctuations, drought), with good fruit set even with a lack of pollinators.
• For greenhouses and tunnels: often parthenocarpic hybrids (not requiring pollination) are used, which produce yields without bees. Also suitable for greenhouses are varieties less susceptible to fungal diseases due to high humidity (Rubatzky & Yamaguchi, 1997; Wehner et al., 2020). Such hybrids usually have long, thin fruits that are convenient to harvest in vertical cultivation.

Summary table of main traits for quick selection:

From Classification to Choice

Now, with this picture of diversity before you, you can approach the selection of varieties for your plot consciously.

• If you need early greens and are ready to harvest every 2–3 days — choose early-maturing bush zucchinis or courgettes.
• If you want to preserve for winter (pickle, make caviar) — pay attention to canning hybrids with dense flesh (often these are courgettes or special pattypan varieties).
• If you have limited space — choose only bush forms.
• If your plot has few bees or you are growing in a greenhouse — look for parthenocarpic hybrids.
• If you want to diversify your table — plant several different groups side by side: a few courgette plants, a couple of pattypans, and, for decoration, a yellow or orange variety.

In the next, concluding chapter, we will bring all this knowledge together and provide you with a step-by-step guide: "How to choose a variety and cultivation method for your specific needs." You will learn how, based on your goals (early harvest, preserving, space saving, ease of care), to select the ideal variety and determine its cultivation strategy.

Step 1. Determine Your Climatic Conditions

What is your climate like, and how long is your warm season?

This is the most important question, as it determines the cultivation method:

Step 2. Determine Available Space

How much space can you allocate to this crop?

Step 3. Determine Your Culinary Goals

What will you use the harvest for?

Step 4. Determine If You Have Pollination Issues

Do you have bees and bumblebees on your plot, especially in the morning hours?

Step 5. Determine Priority: Very Early Yield or Maximum Productivity

What is more important to you: obtaining the first fruits as early as possible or collecting the maximum amount over the season?

Summary Table: How to Choose a Variety for Your Needs

Practical Checklist: Before Buying Seeds

1. Read the description on the package. Pay attention to:

• Maturity period (early, mid-season, late).
• Growth habit (bush, semi-vining).
• Intended use (salad, canning, universal).
• Disease resistance (especially to powdery mildew and viruses — important in humid climates) (Nonnecke, 1989).
• "Parthenocarpic" label, if you need that.

2. Buy seeds from reputable producers. This guarantees germination and conformity to varietal traits.

3. Do not be afraid to try new things. Grow 2–3 different varieties side by side (e.g., one white-fruited, one courgette, and a couple of pattypans) to see which works best for your conditions and tastes.

4. Plan successive sowings. To extend the harvest period, you can do a second sowing in mid-summer (June–July), choosing early varieties for this. This will give you fresh fruits right up to the frosts (Kotov & Adritskaya, 2016).

Congratulations! You now possess all the foundational knowledge needed to choose the ideal varieties of zucchini, courgette, and pattypan squash for your garden.