in Thoreau’s Journal:

Why are some maples now in blossom so much redder than others.

in Thoreau’s Journal:

Not finding the birches, I returned to the first swamp and tapped two more white birches. They flow generally faster than the red or white maples when I tried them. I sit on a rock in the warm, sunny swamp, where the ground is bare, and wait for my vessels to be filled. It is perfectly warm and perhaps drier than ever here. The great butterflies, black with buff-edged wings, are fluttering about, and flies are buzzing over  rock. The spathes of the skunk-cabbage stand thickly amid the dead leaves, the only obvious sign of vegetable life. A few rods off I hear some sparrows busily scratching the floor of the swamp, uttering a faint tseep tseep and from time to time a sweet strain. It is probably the fox-colored sparrow. These always feed thus, I think, in woody swamps, a flock of them rapidly advancing, flying before one another, through the swamp. A robin peeping at a distance is mistaken for a hyla. A gun fired at a muskrat on the other side of the island towards the village sounds like planks thrown down from a scaffold, borne over the water. Meanwhile I hear the sap dropping into my pail. The birch sap flows thus copiously before there is any other sign of life in the tree, the buds not visibly swollen. Yet the aspen, though in bloom, shows no sap when I cut it, nor does the alder. Will their sap flow later? Probably this birch sap, like the maple, flows little if any at night. It is remarkable that this dead-looking trunk should observe such seasons,  —-that a stock should distinguish between day and night.

in Thoreau’s Journal:

As to which are the earliest flowers, it depends on the character of the season, and ground bare or not, meadows wet or dry, etc., etc., also on the variety of soils and localities within your reach

in Thoreau’s Journal:

My life will wait for nobody, but is being matured still irresistibly while I go about the streets and chaffer with this man and that to secure it a living. It will cut its own channel, like the mountain stream, which by the longest ridges and by level prairies is not kept from the sea finally. So flows a man’s life, and will reach the sea water, if not by an earthy channel, yet in dew and rain, overleaping all barriers, with rainbows to announce its victory. It can wind as cunningly and unerringly as water that seeks its level; and shall I complain if the gods make it meander?

in Thoreau’s Journal:

The aspect of April waters, smooth and commonly high, before many flowers (none yet) or any leafing while the landscape is still russet, and frogs are just awakening, is peculiar.

in Thoreau’s Journal:

Begin to look off the hills & see the landscape again through a slight haze, with warm wind on the cheek.

in Thoreau’s Journal:

The atmosphere of morning gives a healthy hue to our prospects.

in Thoreau’s Journal:

It is surprising how the earth on bare south banks begins to show some greenness in its russet cheeks in this rain and fog—a precious emerald-green tinge—almost like a green mildew, the growth of the night — a green blush suffusing her cheek — heralded by twittering birds. This sight is no less interesting than the corresponding bloom & ripe blush of the fall. How encouraging to perceive again that faint tinge of green, spreading amid the russet on earth’s cheeks! I revive with Nature—her victory is mine.

in Thoreau’s Journal:

It is evident that it depends on the character of the season whether this flower or that is the most forward; whether there is more or less snow or cold or rain, etc. 

It will take you half a lifetime to find the earliest flower.

in Thoreau’s Journal:

How unexpectedly dumb and poor and cold does Nature look, when, where we had expected to find a glassy lake reflecting the skies and trees in the spring, we find only dull, white ice. Such I am, no doubt, to many friends.