Making Use of the Pollen Flow

A pollen flow is the period when plants in the area yield abundant pollen and foragers carry it into the hive in large quantities; it directly determines the colony's brood rearing and growth. It gets less attention than the honey flow, yet the early spring and late summer pollen periods in particular matter even more than honey for colony development and wintering. This page explains how to recognise a pollen flow, how to spot a shortage, and how to balance pollen harvesting against the colony's needs.

Why is pollen so important to the colony?

Pollen is the colony's only natural source of protein; it also supplies fats, vitamins and minerals. Nurse bees eat pollen to secrete royal jelly and feed the larvae. Without pollen, no brood can be reared.

Even when there is honey in the hive, once pollen runs out the queen lays less, the nurse bees cannot rear young larvae and colony growth stops. This is a hidden limit often seen in spring: the beekeeper sees combs of honey but cannot understand why the colony is not growing.

Why does pollen diversity matter?

The protein content and amino acid make-up of pollen vary greatly between plant species. Some pollens are rich, others poor; sunflower pollen, for example, is considered a poor food source on its own. Pollen from a single source offers an incomplete protein package.

• Varied diet: Research shows that bees fed pollen from many different plants have better immune indicators and resilience.
• Monoculture farmland: In large single-crop fields, pollen stops abruptly when flowering ends; dearth periods are harsher in these areas.
• Choosing an apiary site: Sites surrounded by trees, shrubs, pasture and roadside vegetation provide more balanced pollen throughout the year.

How do you recognise a pollen flow?

• Watching the entrance: The number of bees coming in with pollen on their legs is a direct indicator. Even a few minutes of counting on a sunny morning gives an idea.
• Pellet colour: The colour of the pollen loads shows which plant is being worked; a variety of colours means a variety of sources.
• The pollen arch in the comb: The width of the pollen band around the brood nest tells you the state of the stores. If the arch is thinning or disappearing, a shortage is approaching.
• Brood condition: In a pollen shortage, young larvae are underfed, the brood area shrinks and sometimes eggs or young larvae are eaten by the bees.

The early spring pollen period

This is the most critical pollen period of the year. As the colony speeds up brood rearing its protein demand is at its highest, while forage outside is still limited and the weather often prevents flying.

• Early sources: Willow, hazel, cornelian cherry, fruit trees such as almond and plum, dandelion and various wild flowers are decisive at this time.
• Winter stores: Pollen stored by the colony in autumn carries brood rearing until forage opens up outside.
• Apiary site: Where there are no early pollen sources, colony development is delayed; in that case consider moving the apiary or supplementary feeding.

The late summer and autumn pollen period

The second critical period is late summer and early autumn. Winter bees are reared at this time. The long life and resilience of winter bees depend on their being fed plenty of pollen during development and building up strong fat bodies.

A late summer pollen shortage means weak winter bees and a risky winter. Late-flowering sources (e.g. sunflower, cotton, late wild plants and, in coastal areas, ivy) are therefore valuable. Timely varroa control at this time is also essential if the winter bees reared on this pollen are to stay healthy.

What should you do in a pollen shortage?

1. Confirm the situation: Assess the lack of pollen-carrying bees at the entrance, a thinning pollen arch and a shrinking brood area together.
2. Give pollen or a substitute: Natural pollen is best; pollen collected and frozen from your own apiary is preferred. Commercial pollen substitutes (protein patties) offer an approximate equivalent.
3. Apply it correctly: Patty-type feed is placed right above the cluster, on the top bars; it must be where the bees can reach it.
4. Give little and often: Give only as much as the bees can eat in a few days; a patty left too long in the hive dries out, goes mouldy or attracts pests.
5. Stop when forage opens up: Supplementary feeding is unnecessary while there is a natural pollen flow.

Balancing pollen harvesting against colony needs

Running a pollen trap directly reduces the colony's protein intake. The basic rule for a beekeeper producing pollen is to run the trap only during an abundant pollen flow, only on strong colonies, and intermittently.

• Signal to close the trap: If the brood area is shrinking and the pollen arch is thinning, close the trap at once.
• Colonies not to harvest from: Do not take pollen from weak colonies, fresh splits or colonies that have just been requeened.
• Critical periods: Do not run traps during the early spring and late summer pollen periods; the colony collects the pollen of these periods for itself.