A guide to the use of poly hives
There are beefarmers in Europe with many thousands of poly hives which can be taken as strong evidence that these hives are both functional and provide a suitable habitat for the bees. There is also anecdotal evidence that poly hives produce larger crops of honey than bees kept in wooden hives. The explanation behind this being the bulk of nectar collected by the bees is used to keep the brood nest warm and therefore better thermally insulated hives should, all other factors being equal, produce a larger surplus of honey at the end of the season. However, there do not seem to have been any controlled trials to substantiate this belief, but it is reasonable to assume bees kept in poly hives will certainly do no worse than bees kept in a wooden hive.
Poly hives are generally significantly cheaper than hives made from the best Western Red Cedar, although hives made from plywood or the cheapest "seconds" quality wood will be comparable in price, but none of these hives will offer the same high thermal insulation which a poly hive can.
Poly hive parts are generally accurately moulded so everything should fit together very accurately and not suffer any warping due to changes in temperature or humidity.
In use the poly hive is not greatly different to a wooden hive, but there are some interesting differences. As the walls of the hives are so thick the walls are not cold and brood rearing will often start to one side of the brood box, rather than nearer the centre as is more common with wooden hives. The outer frames are also frequently used for brood, so when commencing an inspection the beekeeper should be aware that they may well find the queen on an outer frame - which is likely to be the first frame they examine.
The choice of hive tool is usually down to personal preference, but for poly hives the beekeeper is strongly recommended to switch to a "J" tool if they do not already use one. With this type of tool the "J" part is used to lift up a frame while pressing down on the top bar of the adjacent frame. This allows even heavily propolised frames to be removed without damaging the hive, which can happen if the tool is levered against the hive wall.
Separating poly boxes does require a little care. In some designs the sides where the frame ends sit is significantly thinner than the other two sides and the hive tool should obviously not be inserted at this point. The normal method for separating poly boxes is to push a wide but sharp hive tool into the corner and gently prise them apart to break any propolis. Some designs have hard plastic edges which resist the hive tool well, but even with these designs the hive corners can be used. One manufacturer also supplies a special over-centre tool which breaks the boxes apart by using the hand holds only.
There are differences of opinion over whether bees in poly hives will start to raise brood in the spring at a different time to colonies in wooden hives. The fact that there are differences suggests there are no hard and fast rules and location, weather and strain of bee are also likely to play a part and the beekeeper is simply advised to manage colonies in poly hives as they would any other colony, by responding to what they find on inspections. If they find their poly colonies do something a few weeks before or after their wooden colonies they will be forewarned for future seasons. Beekeeping strictly by the calendar is rarely advisable in the highly changeable UK climate.