Updated: Apr 24, 2018
The delight of a double flower, be it a Peony, Ranunculus, Rose or Carnation is a true delight to every gardener. The densely packed ruffled petals draw me in like a child to a jar of sweeties.
However there is a downside to these blooms as many are sterile. For insects they are bad news. In double flowers the pollen tipped stamens are mostly converted into petals so this leaves no pollen for insects to gather, those which are there are so deeply buried inside the ruffled petals that many insects find them difficult to locate. Many pollinators depend solely on pollen as a food source. Nectaries which are the organs which produce nectar are not much better as these are located near to the base of the flower so once again hidden by a mass of ruffled petals. Butterflies, Long horned bees and hummingbirds all need a good source of nectar to feed on.
The next problem is that flowers continue to give out the signal that they are ready for pollinating – through their colour and fragrance. So pollinators will continue to visit double flowers even if they can’t feed on them. Unfortunately many insects have not yet learned which flowers have the food source they are looking for and they will keep going around them all over and over again until they finally find the pollen or nectar they need.
Semi-double flowers are half way between single flowers and double flower and only some of the stamens will have been converted into petals. They may produce as much pollen and nectar as a single flower and their anthers and nectaries will be much easier to reach. If you can clearly see yellow anthers in the centre of the flower it will be easily accessible for pollinators.
So if like me you favour doubles then do have a look in your garden to see if they outnumber the singles. For it is the very insects which feed on the rich sources of pollen and nectar which we need the most. They are the same insects which pollinate our crops. With so many bee populations in decline they really do need a helping hand. Many will travel long distances to find a garden full of flowers.