Meteorological spring has arrived! However, I think it is colder now than it was in January. The frog spawn has arrived in my pond but some of it looks as though it has suffered in the cold and is not developing. However, there are plenty of full stops changing into commas within the jelly, so there should be sufficient tadpoles to produce a new generation of frogs.
I saw the first hawthorn and elder leaves breaking bud recently in the hedgerows, and the dunnock or hedge sparrow was singing his head off this morning, so he is pleased as well, probably because he and his mate can soon get on with nest-building without being too visible.
The honeysuckle is also leafing up in order to catch the early year light before the tree canopy shades it out. It is a striking ecological phenomenon that the small understory herbs, climbers and shrubs produce their leaves well in advance of the trees so that they can use the spring sunshine to get a growing head start on them before the tree canopy closes up above them. It is rather kind of the large trees to let that happen really.
Our commonest tree is probably oak which breaks bud on or about 23rd April on average. Within about four weeks of this date the leaves of the oak have closed the canopy, but not before the wood anemone and blue bell has grown and flowered. However, there are moth caterpillars that hatch out when the oak leaves break bud and eat them as they are growing. If the caterpillars waited, the leaves produce tannin which makes them inedible and the caterpillars would die. Sometimes caterpillars can be in such profusion that you can hear their droppings falling like rain on the leaf litter below. Also, the caterpillars can sometimes eat so many leaves that the oak tree is almost completely defoliated. However, the caterpillars soon pupate if they are not eaten in turn by blue tits and other birds; so then the oak trees produce a new growth of leaves called Lammas growth because it coincides with the feast of Lammas Day or loaf-mass which is the 1st August and the festival of the wheat harvest. On this day it was traditional to bring to church the first loaf of bread made from the first harvest of wheat of that year, and is an early harvest festival.
Dr. Martyn Stenning