Hamlet

The first actual record of a play of Hamlet is in the summer of 1594.

Act 4, Scene 5

Ophelia. There's rosemary, that's for remembrance; pray you, love, remember. And there is pansies, that's for thoughts.
Laer. A doucment in madness, thoughts and remembrance fitted.
Oph. There's fennel for you, and columbines. There's rue for you, and here's some for me — we may call it herb of grace o' Sundays. Oh, you must wear rue with a difference. There's a daisy. I would give you some violets, but they withered all when my father died. They say a' made a good end.

In the language of flowers, each flower mentioned has a meaning. To her brother, she gives rosemary (remembrance) and pansies (thoughts); she gives the king fennel (flattery) and columbine (thanklessness); for the Queen, rue, also called the herb o' grace (sorrow) and daisy (light of love). None of them are worthy of violets (faithfulness).

In line 157 of this scene, Laertes addresses his sister Ophelia as "O rose of May!"

The rose of May is a symbol of perfection of young beauty.

The Winter's Tale

Act IV, sceen IV, at the shepherd's cottage.

The scene opens with a reference to Flora, the goddess of flowers.

Perdita. [to Polixenes] Sir, welcome. 70
It is my father's will I should take on me
The hostessship o' the day. [To Camillo] You're welcome, sir.
Give me those flowers there, Dorcas, Reverend sirs,
For you there's rosemary and rue, these keep
Seeming and savor all the winter long. 75
Grace and remembrance be to you both,
And welcome to our shearing!
Polixenes. Shepherdess,
A fair one are you. Well you fit our ages
With flowers of winter.

Seeming and savor refer to appearance and fragrance. In the language of flowers, rosemary and rue mean "rememberance" and "grace." Perdita goes on the say that she would not have flowers in her garden that had streaks in them due to artificaial crossing. Polixenes argues that nature make the crossing possible so he considered these flowers to still be natural. They call the flowers "streaked gillyvors," but the footnotes in my book say they may be a streaked variety of clove pink. This play was performed in 1611, so they were already crossing plants and making hybrids by that time.

Perdita. I'll not put
The dibble in earth to set one of them, 100
No more than were I painted I would wish
This youth should say 'twere well, and only therefore
Desire to breed by me. Here's flowers for you,
Hot lavender, mints, savory, marjoram,
The marigold that goes to bed wi' the sun
And with him rises weeping. These are flowers
Of middle summer, and I think they are given
To men of middle age. You're very welcome.

The Tempest

The Tempest was written about 1611.

Act I, scene II, line 334: Water with berries in't.

All's Well That Ends Well

Act 1, scene 3, line 136 refers to rose as a symbol of youth.

Act 4, scene 5:

Lafeu. 'Twas a good lady, 'twas a good lady. We may pick a thousand salads ere we light on such another herb.
Clown. Indeed, sir, she was the sweet marjoram of the salad, or rather the herb of grace.
Lafeu. They are not herbs, you knave. They are nose herbs.
Clown. I am no great Nebuchadnezzar, sir. I have not much skill in grass.

Acording to the footnote in my Shakespeare book, sweet marjoram is a herb used in salads. Herb of grace is another name for rue. Nose herbs means herbs used for the scent, not for the taste.

Nebuchadnezzar was smitten with madness. "and he did eat grass as oxen, and his body was wet with the dew of heaven." See Daniel 4:28-37.

It seems that the clown was not the foolish one here.

The Oils

Rosemary

Traditionally, rosemary has been used to improve memory, calm nervous disorders, and to reduce mental fatigue.

Rose

Fennel

Rue

Lavender

Marjoram

Marjoram is also know as "wintersweet" or "joy of the mountains." It has culinary uses and therapeutic benefits.

Mints

References:

2. Shakespeare The Complete Works, edited by G. B. Harrison, Harcourt, Brace & World, Inc., 1968.