The Herb Garden Germination

"The Herb Garden Germination" is the twentieth episode of the fourth season of the  The Big Bang Theory. This episode first aired on April 7, 2011.

Summary
Rumors are spreading about Bernadette having thoughts of terminating her relationship with Howard while Howard is thinking of proposing to her. Sheldon and Amy spread their own rumors to test a theory.

Extended Plot
The episode starts in a with Brian Greene promoting his new physics book: , where he attempts to present complex physics issues in a manner understandable to non-scientists. Included in his audience are Amy and Sheldon who find his explanations to be hilarious. As they listen to his presentation, Amy tells Sheldon a piece of she got from Penny: Bernadette is thinking of breaking up with Howard.

The following day, Leonard and Sheldon are playing  in their apartment when Sheldon brings up his discussion with Amy, passing on the piece of gossip to Leonard. He eventually tells Priya (while explaining how Sheldon requires people to stand away from the mirror when ) who mentions that Raj has a crush on Bernadette and would be happy if Bernadette went ahead with it.

Leonard runs into Penny in the apartment building lobby and tries to pass on the gossip only to find out that she was the root source of the gossip (though she obliviously blames Amy for being the root source of the gossip and complaining about Amy's inability to keep a secret). Leonard follows it up with informing Penny about Raj's crush on Bernadette and noting how it could lead to the end of Howard and Raj's friendship. Penny promises to keep this news secret. Meanwhile, Priya implicitly tells Raj about Bernadette while they're on a with their parents while Priya continuously tries to prevent Raj from telling them about her relationship with Leonard.

At lunch in the university cafeteria, Howard tells the gang that he's. As he disappears to discuss the with his cousin, the rest of the gang express their concern, or in Raj's case, excitement, about the heartbreak he'd get if he tried to ask Bernadette to marry him, only to have her break up with him.

Sheldon and Amy are having drinks in Sheldon's apartment discussing the news that Howard is going to propose to Bernadette. The general interest that the topic had created amongst their social circle intrigues the pair and prompts them to begin experiments to study. To begin their experiment, Amy tells Penny that she and Sheldon had sex and that she was thinking of starting an. Penny tells Raj about Amy and Sheldon after she catches him at the The Cheesecake Factory hitting on Bernadette.

Later, Leonard brings home dinner and starts trying to mine Sheldon for information about his relationship with Amy, mentioning off-handedly that he'd just spoken to Raj. Sheldon deflects the questioning, though he provides a few inquiries to ensure that Leonard was discussing the rumors about sex and not the. After Leonard heads to his room, it's revealed that, during that time, Amy was listening to the conversation via Sheldon's computer. They express surprise at how quickly the information was propagating through the group. By the time dinner happens, Amy has determined that the piece of gossip is known by everyone in their social group, taking less than 24 hours to reach everyone. At dinner, Howard decides to propose there and, to everyone's surprise, Bernadette accepts.

In a follow-up experiment, Amy tells Penny she's with Sheldon's child and she is getting. As she walks down the stairs, she runs into Leonard who had just received a from Penny passing on the news, to his astonishment.

Critics
"The expansion of the gang to include Amy, Bernadette, and Priya has been a huge boon for the show. Suddenly all four of the guys had an emotional involvement in the unfolding story and I don't remember many occasions when that was true... The producers seem to have embraced the need for recurring characters and ongoing stories and the results are very encouraging. I felt engaged for the whole episode and amused by almost everything. If the writers can inject a touch of real emotion into the inevitable breakups coming then I will be hugely impressed." The TV Critic's Review

Quotes
(Sheldon and Amy have commenced their gossip experiment and Amy has started it by going to Penny's the next day)

Penny: Oh, hey Amy, what's up?

Amy: Sheldon and I engaged in sexual intercourse. In other news, I'm thinking of planting a herb garden. --gotta go.

(Amy dashes off, leaving Penny completely surprised and shocked)

(After all the rumors and Howard's proposal, Sheldon and Amy have decided to do their experiment again, with Amy back at Penny's to tell her some more juicy news)

Penny: Oh, hey Amy, Bernadette just texted me, Howard proposed?!

Amy: Yes, not important. Just stopped by to let you know I'm getting orthotics. Also, I'm carrying Sheldon's baby. Mum's the word!

(Amy dashes off again, with a shocked Penny about to text on her phone to tell someone the news. As Amy comes down the stairs, she meets Leonard, who has gotten Penny's text. He looks up at her, completely surprised.)

Leonard: You're pregnant?!

Amy: Wow. Is there anything there about orthotics?

(Leonard looks at his phone confused)

Amy: I’m glad you talked me into this. We work so hard, sometimes, it’s nice to goof off and do something silly.

Howard: Hey, everybody, I got something I want to ask Bernadette, and I can’t think of a better time than when I’m with all my friends.

Leonard: Oh, hold on, Howard. There’s lots of better times.

Raj: Leonard, please. The man is talking. Let him get it out, and let the chips fall where they may.

Howard: Thank you. Bernadette Maryann Rostenkowski…

Bernadette: Oh, God. What’s happening?

Howard: I know things haven’t been perfect with us, and we’ve had our problems, but I just have to tell you, from the moment I…

Bernadette: Howard, let me just stop you right here.

Raj: This is it.

Bernadette: Yes.

Howard: Yes, what?

Bernadette: Yes, I will marry you.

Howard: You will?

Raj: You will?

Bernadette: I will. I will!

Howard: Oh, I love you so much.

Bernadette: Oh, I love you, too.

Leonard: Congratulations!

Priya: Oh, it’s so exciting.

Trivia

 * Bernadette's full name, Bernadette Maryann Rostenkowski, is revealed for the first time.
 * Brian Greene's real book, The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos, was published on January 25, 2011 and there was a book event with Dr. Brian Greene the next day.
 * Sheldon asks Brian Greene why he doesn't do something more useful than educating the general populace about scientific ideas, and suggests reading non-Greene books to the elderly. He finds how Dr. Brian Greene "dumbs down for the crowd" hysterical. Similarly, in "The Luminous Fish Effect", Sheldon states Eric Gablehauser has "done no original research in 25 years, and instead [has] written a series of popular books that reduce the great concepts of science to a series of s, each one dumbed down to accommodate the duration of an average ." Leonard also pointed out to Sheldon, "Well, you did call [Gablehauser] a glorified high-school  whose last successful experiment was ."
 * Sheldon says, "Now I’m thinking about the origin of the phrase train of thought. Now I’m thinking about trains." He similarly provides connections in "The Luminous Fish Effect" ("luminous" and "loom") and "The Bad Fish Paradigm" ("tick" and "tic"). In the latter, he incorrectly refers to a ic relationship.
 * Sheldon wears a, just as he wore a bowling in "The Bath Item Gift Hypothesis", just to play . In "The Bat Jar Conjecture", he cited an old  injury, and he referred to Penny deserving  in "The Dumpling Paradox" after playing Xbox 360.
 * There are two pieces of tape on the floor in Leonard and Sheldon's bathroom. One is in front of the sink and people must brush and floss their teeth from behind this piece of tape. A second piece is in front of the toilet for those that stand up to pee, though what exactly it marks is not specified.
 * During school, Sheldon was with the line "Shelly Cooper is a smelly ". Raj later references this line to Penny.
 * At the end of the episode, the gang thinks that Sheldon and Amy have been having and that Amy has a.
 * Priya urges Leonard to let her see The Roommate Agreement, which plays a part in the next episode, "The Agreement Dissection".
 * Also in the next episode, Amy mentions she recently trained a to smoke s. This monkey, named Ricky, appears in Amy's apartment.
 * When Leonard and Penny talk about Raj's "love" to Bernadette, Leonard says, "Well, the point is, if this got out, it would destroy Howard and Raj's friendship." Ironically, later in "The Skank Reflex Analysis", it is Leonard who reveals this to Howard, causing a turmoil among Howard, Bernadette and Raj. Leonard reveals this by citing Raj's poem "O Bernadette, please play my ", which is told to him by Priya in this episode.
 * Amy's two control rumors are that she is thinking of getting orthotics and that she is planning on starting an herb garden.
 * Priya suggests that they have Howard and Bernadette over to dinner. In The Wildebeest Implementation she does have them over to Raj's apartment for dinner.
 * The title of the episode may be a reference to marijuana culture due to the title referencing 'herb' which coincides with episode #420.