I've had this happen over and over again with skunks. Took me a long time to isolate the culprit, then realize they wanted the grubs in the soil, not just to ruin my day. My carrots never recovered and had to be replanted, the beets were okay after replanting the seeds I could find, brassica seedlings suffered, but partially recovered and I didn't have radish or lettuce (but did lose 12 transplanted white sage seedlings I had germinated myself, which set me to cursing). The skunks come around a few nights a week and I definitely saw them hit the same beds over and over.

Not sure your animal cause is the same as mine, lots of critters dig, but skunks can be physically prevented (they don't climb well) or use beneficial nematodes to kill the grubs. Good luck.

I'm so sorry! I've had this happen to me from the neighborhood cats, though not to the extent you're describing. I can't say for sure it's a cat but I definitely know how you feel. You'll probably need to replant. To keep them out next time, there's another thread on this forum (scroll down a bit and you'll see it) about how to keep cats out of beds. I particularly loved the plastic fork idea someone had. I use bird netting.

Here is a link that might be useful: my blog

It was farther down than expected. Here's a link

Here is a link that might be useful: cats in raised beds

I've been a "raised bed" gardener for over 5 or more years now. Believe me, I feel your pain.

However, I went to a bit of trouble after the first invasion - it took a little of my time - mostly, and a bit of money - to Home Depot. But - it has stood the test of time, and I now harvest food almost every day of the year from my little boxes. The pill bugs, snails and flying predators still take their toll, but the skunks, squirrels, cats, raccoons are now just a minor nuisance - elsewhere.

I purchased some PVC water pipe - 1 inch, and fashioned cages to fit inside of my boxes. The only problem is that each corner needs an "adapter" which is a 3 sided piece that allows the pipe to slide into one side, because one part comes with threads (which pipe can't fit into). It sounds technical but you can see what it entails when you see the pieces.

I cut the pipe so that the cages are about a foot tall, and made it so that it only fits one side of the box - which is about 6 ft. long. This way the cages are small enough to move easily from one box to another as needed, as once plants grow tall enough, the animals seem to avoid the area. Most of the time, they will invade when there is bare or sparsely planted soil. They seem to "get the message" after awhile, and avoid the boxes. I try to keep a cage handy, especially when planting a new area.

The cages are covered with chicken wire - which I hate - but could also be covered with Remay cloth - it would also eliminate the flying pests - white butterfly and birds that like emerging bean and pea seedlings.

This solution has worked for me over the years - as I live next to a large canyon with many predators - a fence is out of the question.

I also put hardware cloth - galvanized wire mesh (Home Depot) nailed to the bottom of the box before putting in my planting soil. They are still working - preventing burrowing critters from invading from the bottom.

The critters seem to "learn" that the boxes are not easy to invade after awhile - and will avoid them, so as the plants grow tall enough to make it difficult for them to penetrate, they will go elsewhere. I can then remove my cage and use it elsewhere.

A little pre-planning - such as making all of the planters the same size, thus only needing one size cage to fit all of them, cuts down on the need to have many different size cages.

Whee - this is rather long-winded, but perhaps you can glean something from my experiences.

Bejay

There are a lot of potential culprits

To prevent most of them from getting in, you'll need a 3-4 ft fence with the bottom dug into the dirt and the top floppy

If they get past that, it's probably birds and you'll need bird netting (but they don't usually dig much)
-ExNJer

Cats won't usually do that much damage. Racoons and squirrels will dig in addition to skunks. My sister had a squirrel come up while she was planting tulips, nab one and weave down the road trying to carry a bulb almost as big as it was. At my previous house, the local animals seemed to know that fresh dug dirt might mean tasty bulbs and they'd dig them up (daffodils wouldn't be eaten, just tossed aside). Here, the neighbor's dog has dug up any pot with bonemeal (I live in the mountains now and folks don't leash their pets). If you used organics like bonemeal, bloodmeal or fish emulsion - your dirt is calling to the local critters - you'll have to use extra procautions. You might want to get a piece of screen, netting, chicken wire or some such and staple it across the top of the bed until your seedlings take off. You might also check your local extension - it could be gophers/moles/voles/ground hogs/rodents coming up through the bottom of your bed in which case you'd need to empty it and put the one inch hardware cloth at the bottom of the bed. Most folks recommend chicken wire does not have a close enough weave to use as a deterrent in the bottom of the bed.

Here is a link that might be useful: mists and enchantments my blog

an electric fence takes care of all things furry except voles, for all seasons.

Thanks so much for all your great advice! We'll see what my husband and I can put up this weekend!

Now...to find out what will survive this mess? Is there any hope for the tiny seedlings, or should I put all effort into replanting?

I would put my effort into replanting. I had the same thing happen with two tidy rows of carrots I'd planted. I'd put a floating row cover over them, but instead of deterring the neighbor's cat, she apparently thought I was just giving her some privacy. I let the seedlings grow, but it was a big mess. Eventually, I just dropped a couple inches of compost over the top and I plan to redo them later.

Here is a link that might be useful: loribees garden blog

I agree it doesn't sound like cats. Cats only dig one hole at a time. Could be skonks, squirrels, or even chipmunks.

Cats often only dig in empty beds, too. If there is something green growing, they know it's not a litter box.
I "plant" sticks in my garden - the very branchy kind, in between plants. I remove them once the plants are slightly larger and are clearly "plants" - raccoons, possums, squirrels and cats seem to respect this and stay out. Won't work for everyone, but it might be worth a try until you make some planting cages.

The same thing happened to me a few years back when I adopted a puppy. Because all my other dogs were adopted as adult/seniors, they usually stay off my raised bed. I was shocked to find out what a hyper puppy can do in a 10 minute potty break. Through scientific data analysis, I found out he was especially fond of blood meal, bone meal, manure and yogurt. Those means party time for the puppy, not so much fun for me.

Usually these seedlings survived a rampage if replanted before totally dried up: brassica such as broccoli mustard, Solanaceous such as tomato pepper eggplant, and any beets lettuce spinach with roots. Those definitely worth to be replanted with care and water.

If you replant, it may be worthwhile to find out who invaded your garden and take precaution. Otherwise history will repeat itself. My puppy is now a few years old, but I still put down chicken wire for new planting if I'm using any of the above mentioned attractants.