shelf, ledge, rack, mount, mantle, trellis
棚 centers on a flat horizontal surface used for holding or displaying things: a shelf, ledge, or rack. Extended uses like a trellis or mantle are specific types of such surfaces.
棚 combines 木 (wood) with 朋, which likely contributes the sound ホウ. The character originally referred to a wooden shelf or rack.
The left side is wood 木, and the right side 朋 looks like two shelves stacked together. Picture a wooden shelf unit made of two planks side by side.
For ホウ, imagine a wooden shelf holding a hoe: hoe -> ホウ, and the hoe rests on the wooden ledge.
shelf; ledge; rack
bookshelves; bookshelf; bookcase
terraced rice fields
cupboard; locker; closet; wardrobe; cabinet
shelving (a matter, plan, etc.); pigeonholing; tabling; putting aside; putting on hold
kamidana; household shrine; home shrine
stocktaking; inventory count
bookshelf
(overhead) luggage rack (on a train, bus, etc.)
to trail (of smoke, clouds, etc.); to hang (of mist, haze, etc.); to lie (over); to linger; to flow (e.g. of hair in the wind)
wisteria trellis; wisteria arbor (arbour); wisteria pergola
godsend; windfall
display shelf; display case
continental shelf
cabinet with double doors (used by the nobility to store books, etc.)
hanging cupboard; wall cabinet
(rock) ledge
display shelf (in a store)
public bath (Edo period)
luggage rack; overhead compartment