A BobCat with a bucket?

However, they take some practice.

I'd hire someone

it would depend on your soil type ...

using an auger in clay.. can create what amounts to a clay bathtub ... which the plant never grows out of ... which usually isnt good ... or create a hole surface.. that doesnt drain properly ....

i would sharpen a shovel.. and do it all by hand ... using the guidelines at the link as to how to plant things ...

see link.. as i presume you wouldnt need large holes for annuals/perennials ....

perhaps you ought to ask the same question in the forums particular to the plants you are planting .... you never know where you will find the answer ...

ken

Here is a link that might be useful: link