Lammas growth, also called Lammas leaves, Lammas flush, second shoots, or summer shoots, is a season of renewed growth in some trees in temperate

Temperate

In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally relatively moderate, rather than extreme hot or cold...

 regions put on in July and August (if in the northern hemisphere, January and February if in the southern), that is around Lammas

Lammas

In some English-speaking countries in the Northern Hemisphere, August 1 is Lammas Day , the festival of the wheat harvest, and is the first harvest festival of the year. On this day it was customary to bring to church a loaf made from the new crop...

 day, August 1, which is the Celtic harvest festival.

It can occur in both hardwoods and softwoods. Examples of common trees which exhibit regrowth are oak

Oak

An oak is a tree or shrub in the genus Quercus , of which about 600 species exist. "Oak" may also appear in the names of species in related genera, notably Lithocarpus...

, ash, beech

Beech

Beech is a genus of ten species of deciduous trees in the family Fagaceae, native to temperate Europe, Asia and North America.-Habit:...

, sycamore

Sycamore

Sycamore is a name which is applied at various times and places to three very different types of trees, but with somewhat similar leaf forms....

, yew

Taxus

Taxus is a genus of yews, small coniferous trees or shrubs in the yew family Taxaceae. They are relatively slow-growing and can be very long-lived, and reach heights of 1-40 m, with trunk diameters of up to 4 m...

, scots pine

Scots Pine

Pinus sylvestris, commonly known as the Scots Pine, is a species of pine native to Europe and Asia, ranging from Scotland, Ireland and Portugal in the west, east to eastern Siberia, south to the Caucasus Mountains, and as far north as well inside the Arctic Circle in Scandinavia...

 , sitka spruce

Sitka Spruce

Picea sitchensis, the Sitka Spruce, is a large coniferous evergreen tree growing to 50–70 m tall, exceptionally to 95 m tall, and with a trunk diameter of up to 5 m, exceptionally to 6–7 m diameter...

 and hawthorn

Crataegus

Crataegus , commonly called hawthorn or thornapple, is a large genus of shrubs and trees in the rose family, Rosaceae, native to temperate regions of the Northern Hemisphere in Europe, Asia and North America. The name hawthorn was originally applied to the species native to northern Europe,...

. This secondary growth compensatex for leaf damage caused by insects during the spring. It is not present in poplar

Poplar

Populus is a genus of 25–35 species of deciduous flowering plants in the family Salicaceae, native to most of the Northern Hemisphere. English names variously applied to different species include poplar , aspen, and cottonwood....

, birch

Birch

Birch is a tree or shrub of the genus Betula , in the family Betulaceae, closely related to the beech/oak family, Fagaceae. The Betula genus contains 30–60 known taxa...

 or willow

Willow

Willows, sallows, and osiers form the genus Salix, around 400 species of deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions of the Northern Hemisphere...

.

Lammas growth declines with the age of the tree, being most vigorous and noticeable in young trees. It differs in nature from spring growth which is fixed when leaves and shoots are laid down in the bud the previous year. The lammas flush is free growth of newly made leaves/needles throughout the tree. One or more of the buds set in the Spring on the ends of terminal and lateral stems will break, and begin to grow, producing a new shoot.