Pollination Value
Part of Beekeeping
Bees are often thought of primarily as honey producers, but their greatest contribution to human food security is pollination. A third of all human food by volume depends on insect pollination, with honeybees responsible for the majority. Understanding which crops need bees, how much yield increases from bee presence, and what happens when pollinators are absent helps justify the resources invested in beekeeping and prioritizes which crops to plant near an apiary.
How Pollination Works
Flowering plants evolved two strategies for transferring pollen between flowers:
- Wind pollination (anemophily): Grasses, conifers, oaks, wheat, rice, maize. These do not benefit from bees.
- Animal pollination (zoophily): Most flowering vegetables, fruits, and nuts. Flowers of these species have evolved colors, scents, and nectar rewards specifically to attract insects.
Honeybees are generalist pollinators — they visit an enormous range of flowering plants. Their behavior (visiting flowers of one species per foraging trip, known as “flower constancy”) makes them highly effective at transferring pollen between compatible plants rather than wasting it on incompatible flowers.
Crops That Require or Strongly Benefit From Bee Pollination
Fully Dependent (No Yield Without Pollinators)
| Crop | Dependency | Notes |
|---|---|---|
| Almonds | Near-total | Commercially grown almonds require managed bees — wild pollinators insufficient |
| Cucumbers | Very high | Requires multiple bee visits per flower for full fruit development |
| Watermelon | Very high | Each fruit requires 500–1000+ pollen grains from multiple bee visits |
| Squash/pumpkin | Very high | Separate male/female flowers; bees must move pollen between them |
| Blueberry | Very high | Blueberry flowers require vibration (buzz pollination) to release pollen |
| Cranberry | Very high | Similar to blueberry; buzz pollination required |
| Kiwifruit | Very high | Separate male/female plants; large-scale bee pollination required |
Strongly Benefiting (30–80% Yield Increase From Bee Presence)
| Crop | Average Yield Increase | Notes |
|---|---|---|
| Apple | 40–80% | Most varieties self-sterile; cross-pollination essential for full crop |
| Pear | 30–60% | Similar to apple; some varieties self-fertile but bee-pollinated fruit sets better |
| Cherry (sweet) | 50–80% | Many varieties require a compatible pollinator variety AND bees to transfer |
| Strawberry | 30–50% | Bee-pollinated strawberries also better shaped (fewer misshapen fruits) |
| Raspberry | 30–60% | Self-fertile but bee pollination dramatically increases berry size and count |
| Field beans (Vicia faba) | 40–50% | Relies on bumblebees and honeybees pushing through flower petals |
| Oilseed rape | 15–30% | Partially self-fertile; bees increase pod number and seed count |
| Sunflower | 20–50% | Cross-pollination improves seed set; some varieties self-fertile |
| Clover (for seed) | 80–90% | Without bees, seed set in clover fields is near zero |
Moderately Benefiting (10–30% Yield Increase)
| Crop | Average Yield Increase | Notes |
|---|---|---|
| Onion (for seed) | 30–40% | Seed production requires insect pollination |
| Carrot (for seed) | 30–50% | Seed crops entirely dependent on insect pollination |
| Tomato | 10–20% | Self-fertile, but buzz pollination (from bumblebees) improves fruit set; honeybees less effective than bumblebees for tomatoes |
| Pepper | 10–15% | Self-fertile; some benefit from insect movement between flowers |
| Courgette | 50–80% | Separate male/female flowers; bees required for fruit development |
Crops That Do Not Benefit From Bee Pollination
| Crop | Reason |
|---|---|
| Wheat, barley, oats, rye | Wind-pollinated grass species |
| Maize | Wind-pollinated; bees collect corn pollen but do not improve yield |
| Rice | Self-pollinating; wind pollination sufficient |
| Potato | Produces fruit/seeds via insect pollination but commercial potatoes are propagated from tubers |
| Lettuce, spinach | Primarily consumed before flowering; seed crops benefit from insect pollination |
The Yield-Per-Hive Calculation
To quantify the value of keeping a colony, estimate the additional yield attributable to its pollination:
Example: Apple orchard, 1 ha, 2 colonies deployed at bloom
- Average apple yield without bee pollination: ~20 tonnes/ha
- Average yield with adequate bee pollination: ~35 tonnes/ha
- Yield increase: ~15 tonnes
- Value of additional yield: depends on local trade value, but substantially exceeds the cost of maintaining 2 colonies
Example: 0.5 ha of courgettes (home market garden)
| Scenario | Expected Fruit Set | Yield |
|---|---|---|
| No managed bees | 40–50% of female flowers | 2–3 kg/m² |
| 1 colony within 100 m | 85–95% of female flowers | 4–6 kg/m² |
In a survival-level food production context, the difference between 40% and 90% fruit set on squash, beans, and cucumbers can be the difference between adequate nutrition and caloric shortfall.
Stocking Density for Effective Pollination
More colonies always produce more pollination, but returns diminish as colony numbers increase. Practical minimums per hectare:
| Crop | Minimum Hives/ha | Recommended Hives/ha |
|---|---|---|
| Apple orchard | 2 | 3–5 |
| Cherry orchard | 3 | 4–6 |
| Blueberry | 3 | 5–8 |
| Oilseed rape | 1 | 2–3 |
| Field beans | 1 | 2–3 |
| Strawberry | 2 | 3–4 |
| Squash/pumpkin | 1 | 2–3 |
| Clover seed | 4 | 6–10 |
Pollination Beyond Managed Crops
The benefits of keeping bees extend beyond your own fields:
Wild plant ecosystem support: Honeybees pollinate hedgerow plants, woodland understorey species, and meadow wildflowers that form habitat and food sources for other wildlife. A healthy hedgerow of hawthorn, blackthorn, and bramble provides berries and shelter for wildlife and humans — all dependent on effective pollination.
Seed saving: Any open-pollinated vegetable grown for seed requires insect pollination if flowers are hermaphroditic or if plants are self-incompatible. Maintaining a colony specifically to service your seed-saving plots ensures genetic diversity and full seed production from your saved varieties.
To observe the direct impact of bee pollination, select 3–4 squash or bean plants and hand-exclude all insect visitors using fine mesh bags placed over flowers at opening. Compare fruit set and size against unprotected plants at season end. The difference is typically dramatic and demonstrates the pollination service value concretely.
Wild Pollinators vs. Managed Bees
Managed honeybees are not the only or always the best pollinators:
| Aspect | Honeybees | Bumblebees | Solitary bees |
|---|---|---|---|
| Colony size | 30,000–80,000 | 100–500 | Solitary |
| Foraging range | Up to 3 km | Up to 1.5 km | 100 m–1 km |
| Cold tolerance | Low (below 12°C) | High (below 8°C) | Variable |
| Buzz pollination | No | Yes | Some species |
| Managed colonies available | Yes | Yes (limited) | No |
| Most effective for | Broad range of crops | Tomatoes, blueberries | Many small-flowered plants |
The ideal pollination strategy combines managed honeybees with habitat for wild bees — hedgerows, wildflower strips, bare ground for ground-nesting solitary bees, and uncut stems for overwintering native species.
Pollination Value Summary
Approximately one-third of human food by volume depends on insect pollination. Crops ranging from apples and almonds to squash and blueberries see 30–80% yield increases when adequate bee populations are present. Clover grown for seed produces near-zero yield without bees. In a food production context, the yield multiplier from keeping even a small number of well-managed colonies near a market garden or orchard is one of the highest returns on biological investment available. Wild pollinators should be supported alongside managed colonies through habitat provision — hedgerows, wildflower strips, and bare ground.