- Crop Guide: Cucumber
- Cucumber Flowers: What You Need to Know
- Cucumber Plant Pollination – How To Pollinate Cucumber By Hand
- Why You May Need to Use Hand Pollination of Cucumbers
- How to Pollinate Cucumber
- Male or Female?
- How To Hand Pollinate The Female Cucumber Flower
- My cucumber plants are producing a ton of flowers. Should I pinch them off?
- To grow delicious cucumbers, learn how they reproduce
Crop Guide: Cucumber
- The origin of cucumbers
- Botanical taxonomy
- Nutritional and health values of the cucumber fruit
- Plant description
- Growth stages
- Flowers and fruits
- Cucumbers types sorted by final usage, morphology and culture practice
The origin of cucumbers
The cucumber most likely originated in India (south foot of the Himalayas), or possibly Burma, where the plant is extremely variable both vegetatively and in fruit characters. It has been in cultivation for at least 3000 years. From India the plant spread quickly to China, and it was reportedly much appreciated by the ancient Greeks and Romans. The Romans used highly artificial methods of growing the cucumber when necessary to have it for the Emperor Tiberius out of season.
Columbus brought the cucumber to the New World, along with many other vegetables. He had them planted in Haiti in 1494, and possibly on other islands. Most of the distinct types of cucumber grown today were known at least 400 years ago. Present forms range from thick, stubby little fruits, three to four inches long, up to the great English greenhouse varieties that often reach a length of nearly two feet.
2. Botanical taxonomy
The cucumber (Cucumis sativus L.) belongs to the Cucurbitaceae family, one of the more important plant families. The Cucurbitaceae consists of 90 genera and 750 species. The genus Cucumis contains nearly 40 species including three important cultivated ones (i.e., C. anguria L. , C. sativus , and C. melo L. ).
Other important crop plants in the Cucurbitaceae family are watermelon (Citrullus vulgaris Schrad), muskmelon (Cucumis melo L.), squash and pumpkin (Cucurbita pepo L., C. mixta Pang., C. moschata Poir., and C. maxima Duch.), and loofahgourd (Luffa cylindrical Roem.). Fig-leaf gourd (Cucurbita ficifolia Bouche) is also cultivated to some extent, but it is even more important as a disease-resistant rootstock in the grafting of greenhouse cucumbers.
3. Nutritional and health values of the cucumber fruit
Table 1.1: The nutritive value of 100 g of edible cucumber
2.2 – 3.6 g
Niacin (vitamin B3)
The high water content makes cucumbers a diuretic and it also has a cleansing action within the body by removing accumulated pockets of old waste material and chemical toxins . Cucumbers help eliminate uric acid which is beneficial for those who have arthritis, and its fiber-rich skin and high levels of potassium and magnesium helps regulate blood pressure and help promote nutrient functions. The magnesium content in cucumbers also relaxes nerves and muscles and keeps blood circulating smoothly.
4. Plant description
The cucumber plant is a coarse, prostrate annual creeping vine that grows up trellises or any other supporting frames, wrapping around ribbing with thin, spiraling tendrils. The plant has large, prickly, hairy triangular leaves that form a canopy over the fruit, and yellow flowers which are mostly either male or female. The female flowers are recognized by the swollen ovary at the base, which will become the edible fruit.
Botanically, the fruit is a false berry or pepo, elongated and round triangular in shape. Its size, shape, and color vary according to the cultivar (Figure 1.1). In the immature fruit, chlorophyll in the cells under the epidermis causes the rind to be green, but, upon maturity, it turns yellow-white. The epidermal layer may have proliferated (warty) areas, each bearing a trichome (spiky hair). The fruit cavity (three locules) contains soft tissue (placenta) in which the seeds are embedded. The regular cucumber bears actual seeds (seeded cucumber), whereas the English cucumber bears either no seeds (seedless cucumber) or barely distinguishable atrophic seeds. Regular cucumbers are short (about 15-25 cm) and uniformly cylindrical. Their thick, deep green skin has light green stripes and a rough surface with strong trichomes. The skin is bitter in taste and not easily digested, so the fruit needs to be peeled before eating. English cucumbers are long (about 25-50 cm) and cylindrical, with a short, narrow neck at the stem end. Their rather smooth surface has slight wrinkles and ridges. The thin skin is uniformly green and not bitter, so the fruit need not be peeled before eating. The cucumber fruit, like that of other Cucurbitaceae, is noted for its high water content, which is around 95% of its fresh weight.
A strong tap root characterizes the root system and may reach 1 m deep. Overall the root system is extensive but rather shallow; many horizontal laterals spread widely and rapidly producing a dense network of rootlets that colonizes the top 30 cm of the soil and usually extends farther than the vine. Some of the lateral roots eventually grow downwards producing a new system of deeper laterals, which replaces in function the tap root as the plant ages. When the base of the plant is
hilled and favorable moisture conditions exist, adventitious roots arise easily from the hypocotyl as well as from the nodes along the vines.
The large, simple leaves (10-20 cm in the regular cucumber, 20-40 cm in the seedless cucumber) are each borne on long (7-20 cm) petioles. They have five angular lobes of which the central is the largest, and many trichomes cover the surface. At each node above the first 3-5, a simple unbranched tendril grows from the base of the petiole. The sensitive tendrils enable the stems, which cannot twist themselves, to climb over other plants or objects. A tendril tip, upon touching a support, coils around it; then the rest of the length of the tendril coils spirally, pulling the whole plant towards the support.
A cross section of the stem reveals 10 vascular bundles arranged in two rings. The smaller vascular bundles of the outer ring (first five) are located at the angles of the stem; the larger bundles (remaining five) form the inner ring.
Shoot. The main stem of the cucumber plant begins growing erect but soon after assumes a prostrate trailing habit and grows like a vine over the ground. The branching is of the sympodial type (i.e., a lateral bud at each node grows and displaces the main growing point, the latter assuming a position on the opposite side of the leaf). From the nodes of the main axis originate primary laterals, each of which can have their (secondary) laterals, and so on. All stems are roughly hairy, have an angular cross section, may turn hollow when mature, and bear leaves singly at the nodes.
1.5 Growth stages
1.5.1 Vegetative Growth
Vegetative growth consists of 2 Stages:
Stage I – Upright growth is the initial stage that starts when first true leaves emerge and it ends after 5-6 nodes.
Stage II – Vining – starts after 6 nodes. Then, side shoots begin to emerge from leaf axils, while main leader continues to grow. Side shoots are also growing, causing the plant to flop over. Leaves are simple and develop at each node. Each flower/fruit is borne on its own stem attached to the main stem at a node.
Depending on variety and environmental conditions, flowers may begin developing at the first few nodes.
Figure 1.2: main development processes and organs developments during first 6 days from germination, under optimal conditions.
1.5.2 Flowers and Fruits
There are different flower types:
- staminate (male).
- pistillate (female). Ovary located at base of the female flower.
- hermaphrodite (both male and female).
Cucumbers are monoecious plants which have separate male and female flowers on the same plant (Fig. 1.3, & 1.4). The male flowers appear first and female flowers shortly later. The female flowers have small immature fruit at the base of the flower and male flower do not have any. Pollen is transferred from male to female flower by bees or other insects. When pollinated properly, female flower develops into fruit. There are different types of cucumber hybrids such as gynoecious varieties that produce predominantly female flowers, and seeds of monoecious varieties are mixed with it for pollination. They are very productive when pollenizer is present.
Figure 1.3: Male flower
Figure 1.4: Female flower
Older cultivars, as well as many current cucumber cultivars, have a monoecious flowering habit, producing separate staminate and pistillate flowers on the same plant. Although the terminology is not botanically correct, staminate flowers are often referred to as male flowers and pistillate as female.
Monoecious cultivars first produce clusters of five male flowers at the leaf nodes on the main stem. Subsequently, the plant produces both male and female flowers.
Most current hybrids are gynoecious (all female flowers). Gynoecious hybrids are widely used because they are generally earlier and more productive. The term “all-female” is somewhat misleading as 5% of the flowers are male under most conditions. These modern F1 hybrids have several advantages. As they bear only female flowers the tiresome job of removing male flowers is unnecessary. They are also much more resistant to disease and rather more prolific. There are two drawbacks – the fruits tend to be shorter than the ordinary varieties and a higher temperature is required. Production of female flowers is naturally promoted by the short days, low temperatures and low light conditions of fall. Flower femaleness can be promoted by applying plant growth substances (PGRs) such as NAA (a type of auxin), and Ethephone ( an ethylene promoter). If a purely female variety is grown, need to provide an appropriate pollinator.
In sensitive gynoecious cultivars, production of male flowers is promoted by long days, high temperatures and high light intensity typical to the summer season. Production of male flowers also increases with high fruit load and with stresses exerted on the plant. Maleness can be promoted by applying PGRs such as Gibberelins as well as by silver nitrate and AVG that act as ethylene suppressors.
There are also cucumber hybrids that produce fruits without pollination. These varieties are called parthenocarpic varieties, resulting in fruits that are called ‘seedless’, although the fruit often contain soft, white seed coats. Such parthenocarpic fruit set also occurs naturally under the low-light, cool-night growing conditions, and short days of fall. Older plants can also produce ‘super’ ovaries which set fruit parthenocarpically.
Parthenocarpic varieties need to be isolated from standard varieties to prevent cross-pollination and development of fruits that do contain seeds, and may be deformed by greater growth in the pollinated area.
Greenhouse cucumbers are naturally parthenocarpic.
Male/female flowering sequence
On a normal cucumber plant, the first 10 – 20 flowers are male, and for every female flower, which will produce the fruit, 10 – 20 male flowers are produced. Flowering set progressively at the nodes.
Developing fruit at the lower nodes may inhibit or delay fruit at subsequent nodes.
Size and shape of the cucumber fruits are related to number of seeds produced.
Since each cucumber flower is open only one day, pollination is a critical aspect of cucumber production. One or more pollen grains are needed per seed, and insufficient seed development may result in fruit abortion, misshapen, curved or short (nubbin) fruit, or poor fruit set. Hence, 10 – 20 bee visits are necessary per flower at the only day the flower is receptive, for proper fruit shape and size. Therefore, it is important to bring hives into the field when about 25% of the plants are beginning to flower. Bringing in the bees earlier is unproductive because they may establish flight patterns to more abundant and attractive food sources such as legumes or wildflowers. Bringing them in later jeopardizes pollination of the first female flowers. It is important to take into consideration that bee activity is greatest during the morning to early afternoon, and that wet, cool conditions reduce bee activity and causes poor fruit set.
Cucumber varieties can cross pollinate with one another but not with squash, pumpkins, muskmelons, or watermelons.
Pollination in gynoecious (“all female flowers”) crops is ensured by blending seed of a monoecious cultivar (pollenizer) with seed of the gynoecious hybrid. Typical ratios are 88% gynoecious, to 12% monoecious. Pollenizer seed is often dyed with a different color to distinguish it from that of the gynoecious hybrid. It is difficult to recognize pollenizer seedlings after emergence in the field. Removing ‘different looking’ seedlings during thinning may leave the field without the pollenizer.
1.5.4 Cucumbers types sorted by final usage, morphology and culture practice
Cucumber cultivars are usually classified according to their intended use as fresh market slicers, pickles, or greenhouse cucumbers. This classification includes several fruit characteristics such as shape, color, spine type (coarse or fine), spine color (white or black), fruit length/diameter ratio, skin thickness, and surface warts.
Each type should be cylindrical with blocky ends, although rounded ends are also acceptable for slicers.
“Pickling” refers to cucumbers that are primarily used for processing and pickling. Increasingly, more pickling cucumbers are being sold fresh for immediate consumption. Some consumers have a preference for the pickling type because they have thinner skins compared with slicing cucumbers. Pickling fruits are lighter green in color, shorter, thinner-skinned, and characterized by a warty surface. All commercial cultivars have either black or white spines on the fruit surface, a trait related to fruit maturity. White-spined cultivars are generally slower in their rate of development and retain their green color and firmness longer than black-spined fruits. Cultivars with black spines tend to turn yellow prematurely, especially under high temperatures, and produce larger fruits that soften with maturity. Consequently, black-spined cultivars are used for pickling in regions where summer conditions are relatively cool. White-spined hybrids have largely replaced black-spined cultivars in warmer growing regions and in areas where once-over machine harvesting is prevalent.
For processing cucumbers, the grower generally has little choice of cultivar since the processor selects and provides the cultivars to be grown. Gynoecious hybrids are grown for just about all machine harvest. These types have also replaced many of the standard monoecious types that were previously used in hand-harvesting pickling cucumbers.
- Shorter growth cycle of 50-60 days.
- high plant populations 240,000/ha (60,000/acre)
- Concentrated fruit set adapts them for once over machine harvest
- Predominantly female types (PF)
- Some male blossoms are produced as 10-12% male pollinator seeds are mixed in with the gynoecious types or the PF types).
- An average yield is 25 t/ha* (11.4 short ton or 460 bushels/acre).
*All tons terms in this publication are metric, unless otherwise indicated.
Slicing (fresh consumption) cucumbers
“Slicing” refers to cucumbers that are sold fresh for immediate consumption as a salad item. Characterized by thick, uniform, dark green skins, slicing cucumbers are longer than processing types, and their thicker skins are more resistant to damage during handling and shipping.
Average yield for slicing cucumbers in e.g. North Carolina is 11-14 t/ha (200-250 bushels/acre, but better yields of 33-37 t/ha (600-650 bushels per acre) can be obtained when growing a crop on plastic which is fertigated.
Fruits for fresh market slicing are preferably long, smooth, straight, thick-skinned, with a uniform medium-dark green color. Fresh market cultivars have fewer spines than processing types. For fresh market slicers, both monoecious hybrids and gynoecious hybrids are available. Vigor, uniformity, and higher yields are some advantages of hybrids over previous open-pollinated monoecious cultivars. Regardless of how they are to be used, cultivar differences in earliness and disease resistance are also important considerations for cultivar selection.
These should have long, relatively narrow fruits, with rounded ends. Dutch greenhouse cultivars are parthenocarpic with gynoecious expression and high-yield potential, while Japanese greenhouse cucumbers are mostly monoecious. Unlike those for processing and some slicing, greenhouse types are fairly smooth-skinned.
Varieties of cucumber include both the slicing or fresh salad type and the pickling type (which can also be used fresh), and dwarf-vined or bush varieties.
The Armenian is a long, often much curved type (as noted, actually a melon); owing to its shape, it is sometimes referred to as the “serpent” or “snake” cucumber. It is hard to recommend a particular cultivar, as few catalogues distinguish one “Armenian” type from another.
This type is also commonly called “Japanese”, though many Oriental nations commonly grow the type (it is also often called “Asian”). It is another long type, usually thin and straight, with a milder flavor than standard types. The Oriental types have many partisans, who find them tender and better-tasting than common cukes (and less bitter and gas-producing), but otherwise generally similar.
The “Beit Alpha” (aka mini, hydroponic, snack-size) type (sometimes called “Persian”) is an Israeli development (developed a lot of useful hot-weather crops, notably melons and lettuces) whose plants are largely or wholly female, and so do not need cross-pollination. They are thought to have an excellent taste and low bitterness. They are well suited for pickling industry due to short length and solid core, as well as their delicate taste.
More recently, short Beit Alpha; parthenocarpic cultivars have taken over the market, as they are adapted for trellising under protected cultivation. Also, short internodes and set multiple fruit in a cluster habit.
The European (aka Dutch, hothouse, greenhouse, hydroponic), fruit develop the characteristic slender, smooth appearance because they are not pollinated. If the flowers are allowed to be pollinated the resulting cucumber fruit will be shorter, bulbous, and irregular and filled with seeds:
- 30 – 35 cm (12 – 14 in.) long
- 3.5 – 5 cm (1.5 – 2 in.) wide
- Thin skinned
Ball and Round
The “ball” types, small spheres (such as the “lemon cucumber”) tend to be especially early. Generally, they are thought to be pleasant but rather low in distinct cucumber flavor, but there are some notable exceptions.
|Armenian||Oriental||Beit Alpha||Ball and round|
Need more information about growing cucumbers? You can always return to the cucumber fertilizer & cucumber crop guide table of contents
NPK Fertilizers – Water Soluble Fertilizers
Plant Fertilizer & Plant Nutrition
Foliar Feeding & Foliar Fertilizer
Potassium Nitrate Fertilizers
Cucumber Flowers: What You Need to Know
Female Cucumber Flowers
Identify a female cuke flower by the area where its base meets its stem. It looks like a miniature fruit. The flower itself is typically longer than a male one on the same vine. At its center is a stigma, where pollen from a male fertilizes the developing fruit.
Male Cucumber Flowers
On most cucumber varieties, male flowers outnumber females by 10 or 20:1. The males also start blooming earlier, and for one or two weeks they shrivel and die before ever pollinating a female. They usually bloom in clusters of three to five flowers. At the center of each is a tubular, pollen-coated anther.
Expert gardener’s tips:
- One way to improve your female-to-male cuke flower ratio is to plant some gynoecious cucumber cultivars. They’re bred to produce mostly female flowers. ‘Greensleeves,’ ‘Raider,’ and ‘Slice Master Hybrid’ are popular examples.
- To maximize the chance of fruit, look for gynoecious seed packets containing a small number of monoecious seeds. They’ll produce plants with enough male blooms to provide your gynoecious cultivars with pollen.
Pruning Cucumber Flowers
As counter-intuitive as it sounds, pruning cuke flowers by pinching them off helps maximize a vine’s yield. To do this, simply hold the buds or flowers between your thumb and forefinger and pinch them off at the bases. Practice pinching when:
- The baby cukes of the first two or three pollinated female flowers start growing. Snap off the blossoms, swollen stems included. If they get big enough to pick, the vine’s growth and flower production will tail off because it’s already produced seeds for a new generation of plants. Sacrificing the early flowers sends a signal that new ones are needed. The vine will respond with an explosion of flowers and fruit!
- Whenever flowers appear later in the growing season. Pinching back one-third to one-half of the new buds directs more energy to the remaining flowers’ developing fruit.
If you add regular flower pinching to your cucumber care regimen, your reward will be bushel baskets full of big, healthy cukes.
Aster Yellows and Cucumber Flowers
Deformed, greenish-yellow cucumber flowers sprouting leafy bracts are infected with aster yellows disease. It’s transmitted when leafhopper insects suck fluids from the vines. To eliminate the leafhoppers, spray the plants thoroughly with organic insecticidal soap.
Cucumber Plant Pollination – How To Pollinate Cucumber By Hand
Cucumber plant pollination by hand is desirable and necessary in some situations. Bumble bees and honeybees, the most effective pollinators of cucumbers, usually transfer pollen from male flowers to the female to create fruits and vegetables. Multiple visits from the bees are required for good fruit set and properly shaped cucumbers.
Why You May Need to Use Hand Pollination of Cucumbers
Cucumber pollination may be lacking in the garden where many varieties of vegetables are planted, as cucumbers aren’t a favorite vegetable of pollinators. Without their pollination, you may get deformed cucumbers, slow growing cucumbers or even no cucumber fruit at all.
If bees and other pollinating insects move on to more attractive vegetables, hand pollinating cucumbers can be your best chance at a successful crop. Excluding natural pollinators and using hand pollination of cucumbers can often produce more and larger cucumbers in the garden.
This method of cucumber plant pollination involves waiting to pollinate until later flowers develop, as early
flowers on young vines may produce inferior cucumbers. Early blooms may be exclusively male. The practice of hand pollinating cucumbers allows vines to grow and have more productive female flowers, usually 11 days or more after blooms begin.
How to Pollinate Cucumber
Cucumber plant pollination, when done by hand, can be time-consuming, but if a crop of large, mature cucumber is desired, hand pollinating cucumbers is often the best way to get them.
Learning to recognize the difference between male and female flowers is the most important aspect of hand pollination of cucumbers. Both grow on the same plant. Male flowers differ in appearance from female flowers by having shorter stems and growing in clusters of three to five, while the female flower blooms singly; alone, one per stalk. Female flowers contain a small ovary in the center; male flowers lack this. The female flower will have a small fruit at the base of her stem. When hand pollinating cucumbers, use only fresh male flowers. Flowers open in the morning and pollen is only viable during that day.
Locate the yellow pollen inside of male flowers. Remove the pollen with a small, clean artist’s brush or break the flower off and carefully remove the petals. Roll the yellow pollen on the male anther onto the stigma in the center of the female flower. Pollen is sticky, so expect cucumber plant pollination to be a tedious and painstaking process. One male anther can pollinate several females. When completed, you have accomplished cucumber plant pollination. This process should be repeated for effective hand pollination of cucumber.
Once you have mastered the art of how to pollinate cucumber, look forward to an abundant crop. Techniques used in hand pollinating cucumbers also allow you to hand pollinate squash and melons in the same way.
This well-pollinated cucumber plant is growing a new cucumber. The fruit comes from the female flower, pollinated by pollen transferred from a male flower, like the bright yellow one above. Ideally, pollen is transferred by bees, but if not, hand-pollination is an option.
If you’re having trouble with pollination of your cucurbit plants, don’t give up. Give hand-pollination a try.
Cucurbits (the family of plants including squash, cantaloupe, watermelon, pumpkins, and cucumber) are notorious for having pollination problems. A short botanical lesson reveals why. Rather than having male and female parts in one flower, like a tomato plant does, cucurbits have separate male and female flowers on the same plant. That means pollen must be carried from one flower to another (male to female) in order for pollination to occur.
Here’s a little more in-depth description of how cucurbits flower: The first flowers on a cucurbit are male, and these may remain on the plant for about a day before falling off. Sometimes, this falling scares gardeners, especially those growing squash, because it seems like blooms are dropping and all is lost. But don’t fear, the female flowers come along soon, and they’re the ones that produce fruit. Female flowers show up on the plant usually a week or two after the male flowers start showing. After that, there should be both male and female flowers on the plant at any given time while the plant’s still blooming.
There are a few ways to distinguish male flowers from female flowers. The easiest way is to look at where the stem meets the flower. On a female, this area will look like small fruit. Male flowers are typically shorter, don’t show immature fruit, and often appear in clusters. Here are a few examples of male and female flowers on cucurbits.
First, some male flowers…
These are male flowers on a zucchini plant.
And now for some females…
This is the female flower on a cucumber plant. See the immature fruit at the base, a clear indication of a female flower. This one has probably already been pollinated and the flower is starting to close.
This is the female flower of a zucchini plant. Due to good pollination, it’s producing a nice-sized zucchini.
This female flower is on an acorn squash plant.
So here’s the trick. Cucurbits need cross-pollination from male to female flowers, but this requires a little more of nature, namely the bees that pollinate our vegetables. If bees aren’t present for some reason, then fruit either doesn’t appear or it appears small and shriveled up because it’s not well pollinated. At this point, human intervention is necessary, and you’ll want to try pollinating your cucurbits by hand. Here is a lesson in hand-pollination using a Straight Eight cucumber plant as the subject.
To hand-pollinate a cucumber, dip a paintbrush into the center of a male flower. Some gardeners use a cotton swab instead of a paintbrush.
The pollen sticks to the bristles on the paintbrush just as it would stick to the hairs on a bee’s body.
Transfer the pollen of the male flower from the paintbrush to the center of the female flower. That completes pollination by hand.
The method of hand-pollination shown above should work well for all cucurbits. You also can remove male flowers and touch the anther (in the center of the male flower) to the female flower’s stigma (also in the center), or shake the male over the female, to transfer the pollen.
Hand-pollination can help you have a great harvest of cucumbers, melons, pumpkins, and squash. Happy growing!
The little cucumber behind this flower means it is a female flower.
Yesterday I posted about the decline in bee populations, so I thought it would be a good idea to discuss one easy task you can do in case you are not getting many bees visiting your garden.
You will know real quick if bees are not coming around. Ever noticed a little tiny cucumber behind a flower on your cucumber vine, just to look again a couple days later and the little fruit has withered and died? This is from a lack in pollination, and pollination has to occur for the fruit to set and develop. This can be a common occurrence with cucumbers, squash, zucchini, pumpkins, and melons. These vegetables depend on bees, and other pollinators, for pollination. If you would like more information on how to attract bees to your garden, please read this article on Attracting Bees To The Vegetable Garden.
Male or Female?
Plants in these families have both male and female flowers. The female flowers have the little tiny fruit behind them, and the male flowers will not. In order for the female plant to produce fruit, it must receive pollen from the male flower.
The little cucumber behind this flower means it is a female flower
This is a male cucumber flower – it does not have the tiny fruit behind it
How To Hand Pollinate The Female Cucumber Flower
First, identify male and female flowers on your cucumber vine. Gently pull a male flower from the vine by grasping it right where the petal stops at the vine. It should just pop right off. Try to leave the flower as intact as possible.
Use a pair of scissors and carefully snip the petals off the flower, until all you have left is the very center, or anthers. Do not touch the anthers – this is where the valuable pollen is located. Touching it could mistakenly wipe the pollen off. You don’t have to remove every little bit of petal, just remove the majority. The purpose is to make it a little easier for the male flower’s anther to come in contact with the female flower’s stigma.
Once most of the petals are removed, it’s time for the pollination. Take the middle of the male flower and gently rub it on the female flower’s middle. You can touch the two flower middles together, then do a slight twisting action. Just roll the male flower slowly back and forth between your thumb and index finger.
That should be enough to do the trick! You have now pollinated this female cucumber flower. This method will also work for squash, zucchini, pumpkins and melons.
If you would like to share your hand pollination techniques, feel free to do so in the comments section below. I’d love to hear them!
Try These Delicious Cucumbers In Your Vegetable Garden
The female flower has an ovary at its base.
You’ve probably noticed have noticed that squash (zucchinis, pumpkins, gourds, etc.), cucumbers, melons and other cucurbits have both female flowers and male flowers. Female flowers are few in number, but easy to see as they already bear an ovary at the base that looks like a miniature version the fruit that will form. So on a pumpkin, it will be rounded, on a cucumber, long and thin, on a patty pan squash, scallop-shaped, etc. In the center of the female flower, there’ll be a crown-shaped stigma.
The male flower has no ovary at the base.
Male flowers have no ovary at their base. They are numerous and far outnumber the females. If you look inside, you’ll see they have a “ball” of yellow pollen on a central stamen, absent, of course, in the female. To produce a fruit, the male pollen must somehow be transferred to the stigma of a female flower.
And this transfer has to happen quickly, the same day the flower opens, because each cucurbit flower lasts only one day.
Sometimes, however, pollinating insects are absent when a female flower is in bloom. This can happen if it’s raining that day or if the weather is unusually hot or cold, all conditions that discourage pollinating insects. Or maybe there are simply very few bees or other pollinators that visit your garden. And it takes up to 12 visits from a pollen-laden bee to completely fertilize the female flower.
How to apply pollen from a male flower to the female flower.
If so, you need play the role of a bee for the day. Harvest a male flower, remove its petals to better see what you are doing, then use it as if it were a brush, touching the rounded end of the stamen, covered in yellow pollen, to the crown-shaped stigma in the center of the female flower. Alternatively, take an artist’s brush or a cotton swab, touch it to a male flower to coat it with yellow pollen, then “paint” the pollen onto the stigma of the female.
In both cases, you’ll be pollinating the female flower, ensuring its fecundation … and resulting in a beautiful fruit a few weeks later!
My cucumber plants are producing a ton of flowers. Should I pinch them off?
Cucumber plants that are healthy and growing vigorously under good conditions can develop an excessive number of flowers—far more than the plant can successfully carry through to fruit maturity—particularly, early in the plant’s life. Often, if left to their own devices, the plant will naturally abort a number of small fruitlets, leaving only those that can be supported.
However, flowering/fruitlet pruning depends very much on the type of cucumber you are growing. The small Lebanese or snacker cucumber varieties produce smaller fruit, so growers typically allow two to three fruits to set at each node as the plant can easily support these.
If growing the large, seedless, continental greenhouse types—sometimes called European, Japanese, or English cucumbers, and are the most commonly grown hydroponically—then all the flowers should be female as the plants are gynoecious (that is, they only produce female flowers as pollination is not required to set and produce fruit).
In this case, the small fruitlets, which have flowers attached to the end, would be thinned to one per node. If you are growing the seeded American slicer or other similar large-fruited and seeded cucumbers, then the plants need both male and female flowers for pollination to occur.
Often, early in the life of a seeded cucumber type, it will first produce a large number of male flowers. These are flowers that don’t have the small cucumber fruitlet at the base as female flowers do.
In this case, excessive male flowers can be removed until the first female flowers are seen. Then pollination can occur. For large-fruited, seeded cucumbers, ideally only one fruit per node should be allowed to develop. You can wait until after pollination has occurred and the small fruitlets have started to grow before selecting the largest fruitlet to grow in each node.
A quick side note: Often, not all the flowers will pollinate if there are multiple flowers in each node. (Also, some of these flowers will be male and naturally fall anyway.) If growing in a greenhouse or indoors, there also may not be any insects to carry out the pollination process.
In this case you will need to transfer pollen from the male to the female flowers. Since this is a time-consuming process, most hydroponic growers prefer the seedless/gynoecious cucumber varieties that set seedless fruit without the need for pollination.
Overbearing can be a problem in many cucumber varieties when under good growing conditions. This can lead to the plant become exhausted and aborting flowers and fruitlets later on. So, to improve fruit size and keep the plant cropping for longer, the number of fruit is controlled with fruitlet pruning where required.
Remember that initially, the first few fruitlets on the plant may wither and fall. This is a normal process for many varieties. The plant will set and carry fruitlets further up the vine once this has occurred and it’s no cause for concern.
To grow delicious cucumbers, learn how they reproduce
If you are going to venture at all beyond the ordinary in growing cucumbers — and you must if want to eat the best tasting ones — then you should think about how they reproduce.
Cucumber flowers are either male or female, and fruits develop only from female flowers. The male flowers supply pollen, which is carried by bees to the female flowers, whose ovaries, once the flowers are pollinated, swell.
Run-of-the-mill cucumber varieties have separate male and female flowers on the same plant. But each cucumber plant is somewhat flexible about its sexuality, pumping out more female flowers in response to better growing conditions. Fruit and seed production, after all, take a lot of energy.
And then there are cucumbers, called gynoecious types, that have been bred to bear only female flowers. After all, why waste any of a plant’s energy producing male flowers?
Gynoecious cucumber varieties tend to yield more fruits and bear them earlier in the season (which is good) but over a shorter period of time (which can be good or bad depending on how you use the cucumbers).
“Whoa,” you might say, “no way those female flowers can swell into fruits without male flowers to provide pollen.” Good point. That’s why seed packets for gynoecious cucumbers contain a few seeds of standard cucumbers to provide enough male flowers — it doesn’t take many — to provide pollen for all those female flowers. Those standard cucumber seeds are dyed for identification.
Another way to get pollen to a gynoecious cucumber is to borrow it from your neighbors. No need to walk next door, though: Bees will carry it over from as far as a half-mile or more away.
Lastly, you might get a gynoecious cucumber to bear fruit by growing a variety whose fruits develop without any pollination whatsoever — a parthenocarpic variety. Like parthenocarpic grapes, persimmons and figs, parthenocarpic cucumbers have no seeds.
Parthenocarpic cucumbers look and taste better when not pollinated. Stray pollen on one of their female flowers causes part of the fruit to swell, as if pregnant. Parthenocarpic varieties, such as Sweet Success and Telegraph, are therefore ideal for growing in greenhouses.
Let’s now move beyond sex and discuss how to find seeds for this summer’s cukes. Most of the cucumbers that you see on grocers’ shelves are so-called American slicers. This year, you might want to grow pickling varieties which, although billed for making pickles, have excellent flavor. For something extraordinary, try Lemon cucumbers, which are round and light yellow. They might look like lemons, but their flavor and texture are pure cucumber.
Other parts of the world offer cucumbers that are, to some palettes, more flavorful than American slicers. From across the Pacific comes Suyo Long, with thin-skinned, soft-spined fruits that are long and curved, crisp in texture and sweet in flavor. From Israel come Mideastern, or beit alpha, varieties, such as Amira, with smooth, tender skins and mild flavor. These varieties are gynoecious and parthenocarpic.
For something extraordinary and foreign, try the Armenian cucumber, also know descriptively as Yard Long cucumber. These fruits have smooth, pale skins and few seeds. Unlike other cucumbers, which lose quality if you let them stay on the vine too long, Armenian cucumbers actually get better and sweeter. Why? Because Armenian cucumbers are, in fact, melons.