What happened to Frodo's house at Crickhollow?

Question

In The Lord of the Rings, Frodo buys a house at Crickhollow after selling Bag End to Lobelia Sackville-Baggins. He goes there on the way to Rivendell, where it is revealed that Merry and Pippin both know about Frodo's plans. What happens to the house after Frodo leaves and it is left in the custody of Fredegar "Fatty" Bolger? Does Frodo ever return to the house? Is it ever mentioned again?

Answer 1

The Black Riders attack the house shortly after Frodo leaves. Frodo was planning to return to the house, but due to the events of the Scouring of the Shire he never did, and Merry and Pippin lived there instead for some time.

• Five days after Frodo leaves, the Black Riders attack the house.

  The house at Crickhollow stood silent. Fatty Bolger opened the door cautiously and peered out. A feeling of fear had been growing on him all day, and he was unable to rest or go to bed: there was a brooding threat in the breathless night-air. As he stared out into the gloom, a black shadow moved under the trees; the gate seemed to open of its own accord and close again without a sound. Terror seized him. He shrank back, and for a moment he stood trembling in the hall. Then he shut and locked the door.

  ...

  There was a faint stir in the leaves, and a cock crowed far away. The cold hour before dawn was passing. The figure by the door moved. In the dark without moon or stars a drawn blade gleamed, as if a chill light had been unsheathed. There was a blow, soft but heavy, and the door shuddered.

  ‘Open, in the name of Mordor!’ said a voice thin and menacing.

  At a second blow the door yielded and fell back, with timbers burst and lock broken. The black figures passed swiftly in.

  At that moment, among the trees nearby, a horn rang out. It rent the night like fire on a hill-top.

  AWAKE! FEAR! FIRE! FOES! AWAKE!

  Fatty Bolger had not been idle. As soon as he saw the dark shapes creep from the garden, he knew that he must run for it, or perish. And run he did, out of the back door, through the garden, and over the fields.
  _{The Lord of the Rings - Book I, Chapter 11, "A Knife in the Dark"}

• After the War, Frodo seems to have planned to return to live at Crickhollow, but ultimately due to the events going on in the shire he heads directly to Hobbiton, and doesn't seem to have gone back, having Merry and Pippin bring back his stuff.

  They had not made any definite plans, but had vaguely thought of going down to Crickhollow together first, and resting there a bit. But now, seeing what things were like, they decided to go straight to Hobbiton.
  _{The Lord of the Rings - Book VI, Chapter 8, "The Scouring of the Shire"}

  In the meanwhile Bag End had been set in order, and Merry and Pippin came over from Crickhollow bringing back all the old furniture and gear, so that the old hole soon looked very much as it always had done.
  _{The Lord of the Rings - Book VI, Chapter 9, "The Grey Havens"}

• After everything settles down, Merry and Pippin live there "for some time". This is the last we hear about Crickhollow.

  Merry and Pippin lived together for some time at Crickhollow, and there was much coming and going between Buckland and Bag End. The two young Travellers cut a great dash in the Shire with their songs and their tales and their finery, and their wonderful parties. ‘Lordly’ folk called them, meaning nothing but good; for it warmed all hearts to see them go riding by with their mail-shirts so bright and their shields so splendid, laughing and singing songs of far away; and if they were now large and magnificent, they were unchanged otherwise, unless they were indeed more fairspoken and more jovial and full of merriment than ever before.
  _{The Lord of the Rings - Book VI, Chapter 9, "The Grey Havens"}

Answer 2

After the hobbits return to the Shire, Frodo's effects are retrieved from Crickhollow and returned to Bag End. This is from Chapter 9, "The Grey Havens", of Book VI:

In the meanwhile Bag End had been set in order, and Merry and Pippin came over from Crickhollow bringing back all the old furniture and gear, so that the old hole soon looked very much as it always had done.

Merry and Pippin also live together in Crickhollow for a while (same chapter):

Merry and Pippin lived together for some time at Crickhollow, and there was much coming and going between Buckland and Bag End.

It is not said that this is the same house, but it is likely. We don't learn much about the geography of Crickhollow, in particular whether it is a settlement of any kind or just a locality where Frodo's isolated house is found. That house "stood in an out-of-the-way corner of the country, and there were no other dwellings close by", according to "A Conspiracy Unmasked" (Book I, Chapter 5). It is also said to have been often used by members of the Brandybuck family who wanted to live near Brandy Hall, but not in the Hall itself, so that could match Merry's situation: it's most likely that this is Frodo's house, which was convenient and vacant, rather than another house.

Presumably, in the next few years they move out, with Pippin marrying Diamond of Long Cleeve, and Merry becoming Master of Buckland. In Merry's case, he would surely be occupying nearby Brandy Hall. We do not learn whether Frodo sold the house, gave it away to the Brandybucks, passed it to Sam along with Bag End, or anything else.