Pollination is the transfer of pollen grains from the male part of a blossom to the female part of a blossom. Fertilization occurs within the ovary when a sperm cell from a pollen grain unites with an egg to produce an embryo which then develops into a seed. After fertilization, the ovary that contains the seed(s) develops into a fruit. Without pollination, fruit production could be sparse to none. Show Busy bee on an almond blossom A pollinator carries the pollen from the male stamen to the female pistil. Even if the stamens and the pistil are within the same blossom, a pollinator is still needed to complete the transfer. Some pollinators can be insects, bats, hummingbirds, or even the wind. Many plants have flowers that require specific pollinators. For example, almond trees depend entirely on honey bees for pollination, and cherry trees are also semi-dependent on honey bees. Some kinds of plants have blossoms that are incompatible with their own pollen and must be cross-pollinated with another closely related variety (in some cases, another individual of the same variety). For example, most apple varieties must be pollinated by a different variety if fertilization (and fruit development) is to occur. Perfect Plants has several varieties of apple trees that will cross pollinate with each other here. Persimmon tree with male flowers on the right (notice the stamens inside) and female flowers that just started fruiting on the left. Persimmon blossoms are either male or female, and a pollinator is required to transfer pollen from the male to the female. The plant that donates pollen to another plant is called the pollenizer. Note that the fruit that develops after cross-pollinating will always be of the variety that received the pollen, and not similar to the plant that donated the pollen. In contrast, the seeds within the fruits that develop from cross pollination will be hybrids between the two parents and will likely germinate to produce plants with characteristics that are intermediate between the two parents, or different from both. For example, if a ‘Red Delicious’ apple is pollinated by a ‘Granny Smith’ apple, the fruits will all be ‘Red Delicious’, but the seeds within those fruits will produce apple trees with different, and often unpredictable characteristics. Of course, pollination works both ways. While the bees are carrying pollen from the ‘Granny Smith’ to the ‘Red Delicious’, they are also moving pollen from the ‘Red Delicious’ to the ‘Granny Smith’ Pollination ChartsThe following fruit tree pollination charts provide examples of which variety will best pollinate the fruit tree of your choosing. Although some varieties are self-pollinating fruit trees, having a pollination match will ensure that your tree produces the best fruit. Apple Tree Pollination Chart
Pear Tree Pollination Chart
Plum Tree Pollination Chart
Pollination Requirements of Some Cultivated Fruit Trees
We have 2 other blogs with valuable information about pollination listed below… It Takes Two to Tango (Except When it Doesn’t)Flowers: Sex, Pollinators and PollinizersPerfect Plants does have several varieties of fruit trees that are self-pollinating and produce fruit without a second tree to pollinate the flowers. Please reach out to us with any questions you may have about cross-pollinating your fruit trees. We would be happy to help! Pollination is one of the most fascinating processes in the natural world. Pollination is how flowering plants reproduce. The process involves the transfer of pollen from the male parts to the female parts of the same or another plant. For some plants, this movement of pollen requires the action of another organism, a pollinator. Plants and their pollinators form a mutualistic relationship, a relationship in which each benefits from the other. In the plant-pollinator relationship, the pollinator benefits by feeding on food rewards provided by the flower, primarily nectar and pollen. In return, the plant benefits as the pollinator moves from flower to flower, transferring pollen as it forages for the food rewards. This movement of pollen allows the plant to reproduce and to exchange genetic information with other plants. Most flowering plants require relationships with pollinators to reproduce. Unfortunately, pollinator populations worldwide are in decline, which negatively affects the flowering plants that depend on them. It also means trouble for humans, as we all depend on the services of pollinators in many different ways, from the food we eat to the air we breathe. This decline in pollinator populations is due in part to human practices that have contributed to a loss of wild and flower-rich habitat. By changing some of our practices, such as how we manage flowering plants in our gardens and farms, we can help conserve these vital pollinator species. Taxonomy basicsTaxonomy is the field of study concerned with identifying, naming and classifying organisms. An understanding of taxonomy can help you select plants that are beneficial to the pollinators in your area. Plants and animals are often called by different names in different locations. The mountain lion (Puma concolor) is also known by the common names puma, cougar and catamount. Conversely, the same common name may refer to completely different species. For example, pileated woodpeckers (Dryocopus pileatus) are called woodcocks in some areas, but the American woodcock (Scolopax minor), or timberdoodle, is not a woodpecker at all. This ambiguity in how common names are applied is why knowledge of the scientific names of plants is necessary to ensure you are selecting the plants you meant to select. Scientific naming systemEarly botanists and zoologists realized that a system of identifying organisms that eliminated such confusions would be essential for communicating descriptions of flora and fauna. In the 1700s, Carl Linnaeus, a Swedish physician and botanist, popularized a naming system in which a species is identified with two Latin names, Latin being the scientific language of the time. In this system, each organism is given a unique combination of two names, one for the genus, which is a group of related species, and one for the species. This system is referred to as binomial nomenclature, which simply means "naming with two names." Scientific names (Genus + species) are denoted in italics, by convention, so they are easily recognizable in publications, as illustrated in the paragraph above. Subsequent uses of the same genus name within a publication are often abbreviated to the first letter, for example, D. pileatus. Taxonomic levelsThe Linnaean binomial system gives us a way to identify and communicate species names across geographic regions and languages, but the field of taxonomy deals with classifying organisms from the broadest of shared characteristics down to those found only in each unique species. Traditionally, there are seven main taxonomic levels, or hierarchies: kingdom, phylum, class, order, family, genus and species. To examine each level more in depth, consider the taxonomy of a very well-known insect pollinator, the common, or European, honey bee (Apis mellifera) (Table 1). Table 1
The variety of organisms narrows at each level of the taxonomy, as indicated by the associated common names. Organisms are grouped at each level based on shared features. As the number of features they have in common increases, fewer organisms exist that share them all. This description of how closely related organisms are to one another is the central theme of taxonomy. Shared features that are useful for taxonomy are often physical traits, such as number of wings or legs; however, in some cases, behaviors can also be useful, as in the family Apidae, which consists hive-nesting or social bees. Cultivated plant species are additionally classified as varieties. Different varieties have been modified through crop-breeding programs to either enhance or eliminate traits present in the native, or wild-type, organism. The taxonomy of the wild cabbage (Brassica oleracea) serves as an example (Table 2). It and several other of our common vegetables are varieties of the same species. Naming systems for plants and animals are similar, but have a few differences, especially at the family level. Animal family names end with -idae (for example, Apidae, Nymphalidae), whereas plant family names end with -aceae (for example, Fabaceae, Rosaceae). This chapter mainly discusses plant-pollinator relationships at the family level, so a general understanding of these naming conventions will be helpful. Table 2
The usefulness of taxonomyTo gain an understanding of how knowledge of taxonomy can be useful, examine the following plant-pollinator relationships. Traits shared at the family level are often the most useful in recognizing and describing related organisms. For plants, these traits are not always visible. For example, plants of the Fabaceae family are excellent soil nitrogen fixers, making them ideal cover crops. Honey bees can often be found — and stepped on — in patches of white clover (Trifolium repens) (Table 3). However, white clover is not native to North America, so producers interested in using cover crops in their fields may want to investigate native Fabaceae, such as purple prairie clover (Dalea purpurea), which may also better support native pollinators such as bumble bees (Bombus spp.). Bumble bees share the Apidae family with honey bees (A. mellifera) and carpenter bees (Ceratina spp. and Xyolocopa virginica), among others. Taxonomy also reveals that species that may outwardly appear to be unrelated, actually have more in common than is first apparent. People are often surprised to learn that watermelons (Citrullus lanatus) and cucumbers (Cucumis sativus) are in the same family, Cucurbitaceae, which also includes cantaloupe, honeydew, pumpkins and squash (Table 4). All members of this family have imperfect flowers, meaning flowers that have either male or female reproductive organs, and they make pollen grains that are too heavy and sticky to be moved by wind. Thus, pollinators are required for these plants to produce fruits. Honey bees can provide this service, but our native bumble bees may be better suited for this task early in the season because they remain active during cooler, wetter weather unlike honey bees. Apples (Malus domestica) also require pollinators to produce fruits. Although apple blossoms have perfect flowers, that is, flowers that contain both male and female structures, most varieties are self-sterile, meaning a tree cannot pollinate its own flowers. Thus, for trees to produce apples, pollen must be transferred from one tree to another, a process called cross-pollination. As is the case with cabbage (B. oleracea), the many varieties of apple are all Malus domestica (Table 5). Other fruit trees within the Rosaceae family include peach (Prunus persica) and cherry (P. avium), both of which also come in many varieties. Mason bees (Osmia spp.) are solitary nesting, native pollinators that specialize in pollinating Rosaceae fruit trees. Because of this specialization, they are often called orchard bees. There are 140 species of mason bee in North America. The blue orchard bee (Osmia lignaria) is one of the few native bees managed for agriculture due to its efficiency as a pollinator. Mason bees belong to the family Megachilidae, as do leafcutter bees (Megachile spp.), another common orchard pollinator that shares the solitary nesting trait (Table 6). Table 3
Table 4
Table 5
Table 6
Applying taxonomical knowledgeAn understanding of plant and pollinator taxonomy can be valuable for mastering knowledge of pollination and improving your property's capacity to support pollinators and thus your harvest. Taxonomy can help you recognize that plants that may outwardly appear unrelated, such as watermelons and cucumbers, are in fact closely related and thus may share a need for the same animal pollinators. Taxonomy can also inform sustainable agriculture practices. For example, plants in the Fabaceae family can help replace soil nitrogen levels between crop rotations while benefiting native pollinators, such as bumble bees. With a basic knowledge of taxonomy, a quick glance at the taxonomic hierarchy of an organism provides information on its pollination or host plant requirements, and thus on benefits of its presence on your land. To practice applying your taxonomical knowledge, fill in the chart below with the complete taxonomy of the golden northern bumble bee (B. fervidas) and the red clover (T. pratense) using only information presented in this section.
Flower anatomyFlowers are the reproductive structures of angiosperms, or flowering plants. Angiosperms comprise most of our food and fiber crops. Nearly all flowering plants require pollination to produce seeds and fruits; these include most of our edible fruit and vegetable crops. In pollination, pollen is transported from the male parts of a flower to the female parts of the same flower or a different flower of the same species. Pollen is a fine, powdery substance made up of microscopic particles or grains. Pollen, especially the small light grains adapted to wind pollination, is usually the cause of spring allergies. Plants have evolved many different shapes, sizes and colors of flowers to attract animal pollinators. These animal-pollinated flowers are typically brightly colored and fragrant, whereas wind-pollinated flowers are typically smaller, dull in color and unscented. From a pollinator's perspective, a flower provides food, typically in the form of nectar and pollen. Nectar is produced by glands called nectaries, which can be located on any part of the plant but are commonly found in the flower. These floral nectaries are typically located near the base of the flower, requiring pollinators to contact the flower's reproductive structures while sipping the nectar and, thus, facilitating pollination.
|
Trait | Usefulness to pollination | Example pollinators |
---|---|---|
More hair | Hairs allow pollen to stick to the pollinator and be transferred to other plants. Without hairs, less pollen is collected and the pollen that is collected is much less likely to stick until the pollinator visits the next plant. | Have this trait: Bees, butterflies, moths Lack this trait: Wasps, ants, beetles |
Larger size | Larger pollinators can usually carry more pollen. Buzz pollination is usually only performed by larger bees. | Have this trait: Bumble bees, hummingbirds Lack this trait: Sweat bees |
Flight | Pollinators that fly usually transfer more pollen than those that walk. | Have this trait: Butterflies, hummingbirds Lack this trait: Ants |
Pollination behavior | Pollinators that visit a large number of flowers in a foraging trip are usually better pollinators. Pollinators that visit a narrow range of plant species on a foraging trip are more successful at pollinating. | Have this trait: Bees Lack this trait: Beetles, ants |
Pollen diet | Pollinators that eat pollen usually come into closer contact with pollen and can pick up more on their bodies. | Have this trait: Bees Lack this trait: Butterflies, flies, hummingbirds |
Close contact with flower | More pollen sticks to pollinators that come into close contact with the flower. | Have this trait: Bees, ants, beetles Lack this trait: Butterflies, moths |
Pollination methods
In nature, gardens and farms, different plant species have a variety of methods to ensure their flowers are successfully pollinated. Some plants use abiotic pollination, which is pollination that is not caused by a living organism but by water or wind. However, most plants use biotic pollination, which requires the help of living organisms to move pollen from one flower to another.
Abiotic pollination
Water pollination is limited to aquatic plants. Pollen travels from one flower to another on or below the water's surface, depending on the plant.
In wind-pollinated species, the pollen is dispersed by air currents from the anthers, in hopes that some of it will land on the stigmas, or receptive tips, of the female pistils. Plants that use wind pollination have numerous tiny dull-colored flowers with little to no nectar or scent because they need not attract pollinators.
Wind-dispersed pollen is smoother and lighter than other types of pollen, making it readily airborne and mobile on air currents. Wind-pollinated plants produce massive amounts of pollen, a fact of which people with allergies are well aware.
Wind-pollinated plants usually grow in stands or close to each other to ensure that pollen can easily reach female flowers of the same species. Plants that use wind pollination include most conifer, or evergreen, tree species; cereal crops — wheat, rice, corn, rye, barley and oats; and most species of grass and sedge. Only about 18 percent of flowering plants use wind pollination.
Biotic pollination
Most plants — about 80 percent of flowering plants and over 33 percent of crop plants — depend on biotic, or animal-assisted, pollination. Plants have found various ways of attracting these animal species to their flowers to aid in pollination. They can attract pollinators by offering food, by having an appealing appearance or fragrance, or even by deception.
The plant-pollinator relationship is mutualistic, because both the plants and pollinators benefit from their interaction. While visiting flowers to gather food, pollinators unknowingly transfer pollen from one flower to another. This pollen transfer results in production of fruits and seeds and thus helps the plant reproduce.
Many flowers produce nectar, a sugary liquid located in the base of the flower, to attract pollinators to the flower. Hummingbird-pollinated flowers contain a large amount of nectar, which hummingbirds depend on for energy.
Some plants produce pollen of high nutritional value for ants and bees. These plants have to produce large amounts of pollen to ensure that not all pollen is eaten but that some is carried to receptive flowers. When a bee enters a flower and begins to gather pollen, some pollen will stick to the hairs on its body. The pollen on its body is then transferred to other flowers that it visits in the same foraging trip.
Visual attraction
Plants attract pollinators based on their flowers' shape, size, color and nectar guides. One of the easiest ways to get a sense of the types of pollinators that visit a flower is by looking at the flower's shape and size. Scarlet beebalm (Monarda didyma) has tubular flowers, and columbines (Aquilegia spp.) have spurred flowers. Both these shapes are suited to pollination by hummingbirds or butterflies with a long proboscis, which allows them to reach the nectar at the base of the corolla tube or spur. Shallow flowers with large open petals act as a landing pad for bumble bees (Bombus spp.), beetles (order Coleoptera) and butterflies (order Lepidoptera), whereas flowers with smaller landing pads and smaller openings may be visited by smaller bees, such as honey bees.
Flowers may be specialized as well. For example, long tubular flowers may prevent small-bodied or short-tongued insects from collecting nectar and thus specialize on larger pollinators like hummingbirds, moths and butterflies that have a long proboscis. Specialization can pose a problem; if no suitable pollinators occur in the area, the plant will be unable to produce seeds and fruit.
Generalists are more flexible. Sunflowers (Helianthus annuus), like many of the flowers in its family (Asteraceae), are visited by a variety of insect pollinators. Honey bees will pollinate many common fruit and vegetable plants and various types of wildflowers.
Pollinators show preferences for shapes that fit their foraging adaptations, such as body size and tongue length (Table 8).
A flower's color is also a clue to the types of pollinators it attracts (Table 9). Hummingbirds are attracted to red and yellow flowers. Butterflies are drawn to red, yellow, orange, pink and purple flowers. Nocturnal pollinators, such as bats and moths, will visit pale-colored or white flowers that remain open at night and are easiest to see in the dark. Some flies prefer flowers that are dark red, purple or spotted because they resemble rotting flesh. Bees are attracted to whites, yellows, blues and purples and can even see ultraviolet (UV) patterns on flowers that humans cannot (Figure 23). These preferences are also something to keep in mind when buying hummingbird feeders; those with yellow plastic flowers will also attract bees.
Bees are also drawn to flowers by nectar guides, which are patterns on the petals that direct them to the center of the flower where the pollen and nectar are located. Nectar guides resemble a bull's-eye or stripes near the flower's center, and they often involve UV coloration.
Figure 23A yellow aster (Asteraceae sp.) as seen with human vision (top) and its UV-visible bull's-eye (bottom).
Table 8
Typical flower shapes associated with different pollinators.
Flower shape | Pollinator | ||||||
---|---|---|---|---|---|---|---|
Bee | Butterfly | Hummingbird | Moth | Fly | Beetle | Ant | |
Cup-shaped (campanulate, cupuliform, saccate or urceolate) | X | X | X | ||||
Bowl-shaped or open (coroniform, cruciform, ligulate or stellate) | X | X | X | X | X | ||
Tube-shaped (funnelform, salverform or tubular) | X | X | X | ||||
Labiate | X | ||||||
Papillionoid | X | ||||||
Reflexed | X | ||||||
Spurred | X | X |
Table 9
Flower colors that attract particular pollinators.
Flower color | Pollinator | |||||||
---|---|---|---|---|---|---|---|---|
Bee | Butterfly | Hummingbird | Moth | Fly | Bat | Beetle | Wind | |
Red | X | X | X | |||||
Orange | X | X | ||||||
Yellow | X | X | ||||||
Green | X | |||||||
Blue | X | |||||||
Purple | X | X | X | |||||
Pink | X | X | X | |||||
White or pale | X | X | X | X | ||||
Ultraviolet (UV) | X |
Odorous attraction
In addition to producing visually attractive flowers, plants produce fragrant flowers to attract pollinators. Flowers that we normally think of as pleasant-smelling produce these scents to attract butterflies, bats and moths. Some flowers produce scents so strong they can be detected by insects more than half a mile away. When scent is the primary method of attracting pollinators, the flowers need not be as showy; thus, plants that use scent to attract pollinators may not have colorful flowers. Fragrant flowers are characteristic of summersweet shrub (Clethra alnifolia), roseshell azalea (Rhododendron prinophyllum, family Ericaceae), spicebush (Lindera benzoin, family Lauraceae) and magnolia (family Magnoliaceae) trees.
Some plants produce unpleasant smells that mimic the odors of rotting flesh or dung to attract flies and beetles. While inspecting the flower to locate the source of these odors, the insect comes in contact with pollen. Plants that depend on flies as pollinators include the pawpaw tree (Asimina triloba), skunk cabbage (Symplocarpus foetidus) and the world's largest flower, the corpse flower (Amorphophallus titanum). Unlike the usual mutualistic plant-pollinator relationship, this relationship is commensalistic, in that the plant benefits from the interaction because pollen is transferred from one plant to another, but the pollinator receives no benefit.
Applying knowledge of pollination methods
By closely looking at, and smelling, a flower, you can often figure out what pollination method it uses to attract pollinators. Plants use color to attract hummingbirds, butterflies or bees; these pollinators are more visually oriented. A flower's shape may also suggest a plant's pollination method. Narrow or tube-shaped flowers usually have hummingbirds or long-tongued butterflies as pollinators, whereas wide open flowers attract bees and beetles. Flowers that are dull may use scent to attract pollinators or may be wind-pollinated. Plants may also imitate the appearance or smell, or both, of another insect or food source to trick insects into pollinating their plants.
Seasonal bloom times
Because most pollinators have a longer lifespan than flowers of a single plant can provide nourishment for, multiple plants, often of different species, need to be available for them over the course of the growing season. To meet their nutritional needs, animals must visit plants that bloom at different times. Although many plants bloom in late spring and early summer, there are plants that bloom during most times of the year. These varying bloom times allow pollinators to acquire food and nutrients from different plant species from early spring to late fall.
Spring bloomers
Several plants grown in Missouri bloom in early spring. One such plant is the wild plum (Prunus americana), which provides benefits to both wildlife and humans. As mentioned in the flower anatomy section, wild plum is a monoecious species with perfect flowers. Its flowers bloom in April and May, and are pollinated by various bee species, including honey bees (Apis mellifera) and bumble bees (Bombus spp.). Wild plums are also host to many butterfly (order Lepidoptera) species. As an added bonus, wild plum plants will provide you with a delicious source of fruit in the late summer that can be used for jams and pies.
Farmers growing corn or other row crops often plant a cover crop between rotations of the main crop to help keep the soil fertilized and make it is as nutrient-rich as possible when the main crop is planted. Red clover (Trifolium pretense) is a commonly used cover crop in Missouri. A member of the Fabaceae family, red clover is a legume that will bloom in late May, providing food for bumble bees.
For a home garden, plants such as beardtongue (Penstemon spp., family Scrophulariaceae) and both false and wild indigo (Baptisia spp., family Fabaceae) can be planted in early spring and will bloom from late spring into summer. These plants will bring color to your garden and attract a variety of bee species for pollination.
For all of these plants, one of the biggest risks is frost. Because they bloom in the spring, a late frost could kill their flowers before the plants are successfully pollinated. Another risk is that many pollinators, such as bees, often have not had a chance to build up their populations by the time these early blooming plants flower. Therefore, spring bloomers run the risk of not getting enough visits from pollinators to reproduce.
Summer bloomers
In Missouri and the surrounding areas, several types of melons (family Cucurbitaceae), including watermelons (Citrullus lanatus), are grown, all of which require pollinators to produce fruit. Watermelons have imperfect male and female flowers on the same plant, and their pollen is so heavy that it cannot be moved by wind. Due to these characteristics, watermelons require pollinators for sexual reproduction and fruit set. To produce a marketable watermelon, the female flower must receive 500 to 1,000 pollen grains.
Bumble bees, and other native bees, are the most effective pollinator of watermelons, as they can deliver more pollen on each flower visit. Watermelons typically bloom during the heat of the summer, in July and August.
Native persimmons (Diospyros virginiana, family Ebenaceae) bloom in early summer, from May to June, and are pollinated by honey bees and other native bees.
Many native perennials bloom in the summer months and are serviced by animal pollinators. One example is milkweed (Asclepias spp., family Apocynaceae), which has pinkish-purple flowers and blooms from June to August. Pollinated by a variety of insects, milkweed is important to monarch butterflies in particular. Monarch larvae feed exclusively on milkweed and the plant, in turn, is pollinated by the adult butterflies. Scarlet beebalm (Monarda didyma L., family Lamiaceae) is another plant that blooms from late June through late August. Because of its long narrow flowers, it is pollinated by long-tongued butterflies and hummingbirds. The presence of both of these plants in an ornamental or native plant garden could sustain a variety of pollinators over the summer.
In addition to plants that are visually pleasing, some herbs that are used as spices can be planted in a garden and provide resources for pollinators. Two examples are oregano (Origanum vulgare, family Lamiaceae) and fennel (Foeniculum vulgare, family Apiaceae). Oregano leaves can be eaten before the plant blooms, but if allowed to bloom in mid- to late summer, it will provide nectar for bees and hummingbirds. Fennel, which blooms from mid- to late summer, will attract bees, as well as flower-visiting wasps and hoverflies.
The risks for plants that bloom in the summer include loss of flowers and foliage to insect herbivores, and potential competition for pollinator visits with the many other species of plants also in bloom. The potential also exists for damage to flowers from hail and severe winds. In addition, the lifespan of a flower depends on both temperature and available water. Under summer heat and drought, nectar can dry up. When this happens, pollinators may lack sufficient energetic resources to raise their young.
Autumn bloomers
Although many people focus on their gardens only in late spring and early summer, a garden can be extended into the fall. Many species bloom late in the fall, and planting them in a garden will ensure flowers are available for pollinators whose life cycles extend late into the year. Some of these late-blooming plants include asters (genera Symphyotrichum and Eurybia., family Asteraceae) and gentian (Gentiana L. spp., family Gentianaceae). The plants bloom in late August through October and are pollinated by various bee species. Sunflowers also continue to bloom well into autumn and are visited by a variety of insect pollinators. One shrub common in Missouri that blooms from mid-November through mid-March, depending on the subspecies, is witch hazel (Hamamelis spp., family Hamamelidaceae). In mid-Missouri, honey bees can be seen visiting its flowers in mid-January.
Plants that bloom in the late summer through the autumn and winter months are at risk of storm damage and early frost. These natural events damage the flowers and prevent them from successfully reproducing. Late-blooming plants also suffer from low numbers of pollinators, as hummingbirds migrate south and bee colonies dwindle. This risk can be reduced if an abundance of flowering plants is available for pollinators earlier in the summer and fall.
Applying knowledge of bloom times
Using knowledge of the bloom times of various plants, you can choose to grow plants that flower at different times throughout the year, thereby ensuring that a variety of pollinators are available throughout the growing season to pollinate your fruit trees and garden vegetables.