Have you taken great care of your fruit tree, yet it still refuses to produce fruit? Don’t take it personally! In most cases, the issue comes down to pollination. To better understand why, let’s take a closer look at how plants reproduce.
Plant Reproduction
To ensure the survival of their species, plants must reproduce. They do so using two main strategies: asexual reproduction and sexual reproduction.
Sexual Reproduction
Sexual reproduction involves pollination and genetic exchange between plants. The resulting offspring carry genetic material from both parents, increasing diversity. This diversity improves a plant’s ability to adapt to environmental changes and resist pressures such as diseases and pests.
For fruit trees and shrubs, reproduction is primarily sexual, as fruit plays a key role in seed dispersal.
Asexual Reproduction
This type of reproduction occurs without pollination. A single plant produces offspring from its own tissues, resulting in new plants that are genetically identical to the parent.
Asexual reproduction is especially useful when few individuals of the same species are nearby or when pollinators are scarce. It allows plants to spread quickly and colonize new environments.
Some species rely heavily on this strategy—for example, invasive phragmites, which can spread aggressively at the expense of native plants.
This is also the method gardeners use to reproduce desirable cultivars. Techniques such as cuttings, grafting, layering, and division all produce clones.
Greenhouse cuttings
Pollination: How Does It Work?
Pollination is the transfer of pollen from the anthers (male part of the flower) to the stigma (female part).
This process can occur through wind, water, animals (such as insects, birds, and bats), or self-pollination.
Once on the stigma, pollen germinates and forms a pollen tube that grows down through the style to reach the ovule. This allows fertilization to occur, leading to the formation of fruits and seeds.
Pollination is essential for plant reproduction and plays a key role in maintaining genetic diversity.
To better understand how plants reproduce, botanists classify species based on their reproductive systems.
Hermaphroditic Species
Hermaphroditic flowers contain both male (stamens) and female (pistil or carpel) organs within the same flower. This is the case for apple trees, cherry trees, and maples.
Figure: Typical flower anatomy in hermaphroditic species
Monoecious Species
Monoecious plants have separate male and female flowers on the same individual (e.g., hazelnut).
In theory, monoecious and hermaphroditic plants can self-pollinate. However, cross-pollination is often needed for successful fruit production.
This means planting a second tree of the same species—but a different variety—that blooms at the same time. For example, an orchard planted entirely with ‘McIntosh’ apple trees would produce very little fruit. Adding a compatible variety significantly improves yields.
If a monoecious or hermaphroditic tree flowers but does not produce fruit, it is often due to the absence of a compatible pollination partner nearby.
Dioecious Species
Dioecious plants produce only one type of flower (male or female) per individual. Male plants produce pollen, while female plants produce fruit—but only if a male plant is nearby.
If a healthy dioecious tree flowers but never produces fruit, it may simply lack a nearby plant of the opposite sex.
When planning, it is important to include at least one male and one female plant of the same species. Since it can be difficult to determine the sex of a plant before flowering, planting multiple individuals increases your chances of success.
Examples of Dioecious Trees and Shrubs in Eastern Canada
Trees
- White Ash (Fraxinus americana)
- Black Ash (Fraxinus nigra)
- Maidenhair Tree (Ginkgo biloba): Female trees produce foul-smelling fruit, which is why male trees are most commonly planted.
- Eastern Red Cedar (Juniperus virginiana) and Common Juniper (Juniperus communis)
- Poplars (Populus spp.)
- Willows (Salix spp.)
Shrubs
- Arctic Kiwi (Actinidia kolomikta): 1 male for 5–7 females
- Sea Buckthorn (Hippophae rhamnoides): about 1 male for 6 females
- Winterberry (Ilex verticillata): 1 male for 5 females
- Canada Yew (Taxus canadensis)
- Riverbank Grape (Vitis riparia)
How Can I Tell If My Tree Is Male or Female?
During flowering, observing the flowers is the only reliable way to determine sex.
Male flowers produce pollen, often visible as a fine yellow dust. Female flowers typically have well-developed ovaries.
If unsure, compare several plants of the same species—each will show distinct flower structures.
Biodiversity and Pollinator Protection
Understanding plant reproduction helps gardeners and growers improve fruit production and support biodiversity.
Pollinators play a critical role in this process. Their decline—due to pesticides, habitat loss, and disease—poses a serious threat to ecosystems and food production.
Protecting pollinators helps maintain healthy landscapes and food systems.
Article co-written by Audrey Rondeau, Biol., M.Env., and Suzanne Simard, horticulture writer and horticultural technologist.
