An exceptionally mild February has made everything put on a spurt of growth. Our garden has been a picture with spring bulbs and a large patch of naturalised crocuses. The only downside is all the ‘unwanteds’ have been growing apace as well. It is incredible how nature has devised different methods of distributing seeds.
Many of our trees, such as oak, beech and walnuts bear fruits that are attractive to jays and squirrels. They not only eat them but also store them for winter by burying them in the ground. They never find all of what they’ve buried and hey presto a new tree has been planted some distance from its parent! Other trees and shrubs rely on birds to scatter their seeds but by a more devious method. Hawthorn, yew, mountain ash, spindle, cherry, as well as several others, are popular with blackbirds, redwings etc for food. However the stones or pips inside prove indigestible and pass through the birds. These are then deposited wherever they happen to be at the time, each with its own dressing of fertilizer. Another clever method used by trees, such as sycamore and ash, to distribute their seed is to have ‘wings’ on them. These are called ‘keys’ and can be carried quite a distance by the wind. Last autumn we had an amazing amount on our sycamore tree which are now growing like cress in the borders and lawn! Fir cones open up to scatter their seeds. Some species of conifers, such as the Lodge Pole Pine in North America, need excessively high temperatures for this to happen and benefit greatly when forest fires trigger this mechanism. In 1988 there were devastating fires over thousands of acres in Yellowstone National Park and within a few years a natural forest was regenerating among the gaunt, charred remains of the original trees.
Goldfinches relish the fluffy seed heads of groundsel, dandelions and thistles but they don’t eat them all. Individually they are so light they float away in the gentlest of breezes to spread themselves elsewhere. Then there are the sneaky plants whose reproduction technique is to cadge a lift in order to disperse themselves. Perhaps the best known is cleavers, more familiarly known as ‘goose grass’ or ‘sweethearts’. The tiny green balls of their seeds seem to be able to cling to almost everything. A much larger plant that also has this unpleasant habit is the burdock. If you have a long haired dog which has ever got too close to a burdock you will know exactly how hard it is to remove the burrs. Of course there are a few lazy plants that just rely on producing thousands of seeds which simply fall to the ground. Their reproduction is guaranteed purely by the sheer quantity they produce. ‘Busy Lizzies’ have a brilliant method. When lightly touched their ripe seed pods burst open with an audible ‘pop’ and fire out the contents. How clever is that?