They can either be for earthworms or even better for red wigglers.
Worms for garden beds.
So no it s not necessary to add worms to raised beds even if you could find any for.
The worms that you can buy are usually redworms which you ll find in finished compost or in the mulch layer of a garden.
Instead of adding organic matter to a pile and waiting for it to decompose into usable compost that you add to your garden adding worms directly to a vegetable garden bed allows you to provide.
Worms will find their way to the raised bed garden through the wood.
The worms that work the soil making tunnels and creating good soil structure are earthworms which are not generally ever for sale.
Generally speaking there is no need to add worms in raised bed garden.
The presence of worms in your soil is an indicator of a healthy garden.
Place the soil on a tarp and count the number of worms in the sample.
You should check what is the size of the worms and whether they are good enough to multiply themselves quickly to benefit your raised garden beds.
But if you just built a new bed garden it will take some time before worms find the way to your new bed.
Dig up a section of ground 12 inches by 12 inches and about 6 to 7 inches deep.
So it is good to cheat for once for your bed.
The average size of the worms is between 1 to 2 inches and they multiply quite quickly.
There are a few differences between a worm bed and a regular garden bed but they share many attributes.