The best natural feed for honey bees is an abundance of pollen- and nectar-producing plants. Beekeepers have always sought to increase bee pasture by various means. Anecdotal evidence indicates that in the mid western U.S. much of the extant white sweet clover was planted by beekeepers over many decades. Of continuing concern is the future of nectar-producing plants as land use changes. It now looks that honey bees are in fact more challenged than ever as their pasture is converted to other uses, and this is one of the layered causes of what is termed “colony collapse disorder.”
Beekeepers should recognize that only a few of the many existing blooming plants are major nectar producers, although most will provide at least some nectar and/or pollen to bees at certain times of the year. The vast majority of beneficial bee plants are feral or wild in nature. This makes beekeeping, like fishing, an extractive industry. It is based largely on using plants that are not cultivated, and are subject to many influences outside the beekeeper’s control.
In the mid west, for example, corn and soybean plantings have often led to the cultivation of marginal lands, previously reserved by default for many nectariferous plants. And in the south, urban sprawl and extensive drainage of land for agricultural purposes continues to reduce land inhabited by plants beneficial to honey bees.
There is no unanimous agreement on how to solve the dilemma of decreasing nectar resources. Several ideas have been suggested including: (1) large scale agricultural planting of nectar secreting crops; (2) sowing roadsides, reclaimed mining areas and fallow land with nectariferous vegetation; (3) developing plants that are superior nectar producers through genetic engineering; and (4) introducing species that are proven nectar producers in other regions. Recently, the plight of honey bees has been recognized by governmental offices and several initiatives to increase forage have been initiated.
Traditionally, large scale planting of bee forage has not been considered profitable. The practice has only been encouraged when another use for the crop was possible. By far, the plants most cultivated in the U.S. have been for livestock forage such as clovers and alfalfa. Most of these, however, reach their nutritional peak and are cut just before or as they bloom. Therefore, a trade off is often necessary between nectar production for honey bees and the nutritional requirements of livestock.
Seeding roadsides and public use lands often requires extreme political pressure by local beekeeping organizations. Although there have been successes, a continuous effort to maintain these programs is essential. Another strategy is the use the tax laws to make more forage available, in essence creating partnerships between landowners and beekeepers.
Genetic engineering to increase nectar secretion by plants is not a common practice in U.S. plant breeding at the moment. This is partly because beekeepers and/or bee researchers have not been actively involved in plant breeding projects. However, with emphasis on hybrid seed production, much of which requires insect pollination, there will be more attention given to this area in the future. A successful example of cooperation between plant and bee scientists is the effort in Hungary to produce black locust trees which secrete large amounts of nectar and also provide timber.
Importing plant species that are known nectar producers from other areas is a dangerous and unreliable strategy to increase bee forage. Introduced plants can be responsible for out competing and eliminating native vegetation. Two exotic plants found in the state of Florida, though not purposefully planted for nectar production, are in this category: the punk tree, Melaleuca quinquenervia and Brazilian Pepper, Shinus terebinthifolius. Both are categorized as “noxious weeds,” by many, but for beekeepers these plants are often prime producers, especially in times of the year when other plants are not available. This can be a source of friction among competing human communities (i.e. those attempting to retain native vegetation vs beekeepers looking for maximum nectar production).
Like the honey bee itself, many excellent nectar plants are considered exotic species. There are many examples world wide of plants that are introduced into different habitats, many considered “invasive,” that have become good nectar sources for honey bees. These include the two Florida plants already mentioned, manuka in New Zealand and a prime nectar source in Europe, Robinia pseudocacia.
Honey bees are not necessarily benefited by all plants. Most plants produce toxic chemicals to ward off browsers and this can catch beekeepers by surprise in some areas. It is important to be fully informed of possible toxic plants in specific areas, the reason for keeping contact with local beekeeping associations.
No one strategy will provide the definitive answer to decreasing bee pasture. Instead, some combination of those mentioned above should probably be pursued in the future. And it will be up to beekeepers to show interest and provide guidance in this arena if the current trend toward bee forage reduction is to be reversed.