With all the snow and ice covering Britain and parts of Europe not many will be thinking about pollination. However for those lucky enough to find time to spend in the office or garden shed you may be planning ahead and asking: “What type of tunnel will I use next year?” or “How will my crops be pollinated if I seal up my tunnel”.
Cherry flower, Haygrove Farm organics 2010
Even as early as December English strawberry growers will be planting cold stored plants that have received enough chilling and glasshouse salad crops will be taking delivery of new plants for early, heated crops. Both these will be have consider pollination very carefully and will be using bumble bees.
Some important points to remember if you are planning to seal up your tunnel or glasshouse for maximum earliness:
- If the structure is sealed to retain heat (or to exclude insects) pollinating insects will need to be placed on the inside or flowers pollinated by hand
- Bumble bees are best for pollinating early crops. They are not aggressive and fly at relatively low temperatures.
- Don’t forget that, if the sun comes out, temperatures in a sealed structure will rocket upwards. That will cause bees to retreat to their hive, on fanning duty, to protect their brood and will also mean that your plants are use more energy respiring than they make photosynthesising. For most crops its not a good idea to let the air temperature rise above 25 degrees C.
- For small structures its usually best just to leave the door open and let local bees and other nectar feeding insects do the pollinating. For tomatoes many growers appear to find that their own business and some air movement provides pollination.
