These are newly planred, but starting to leaf out
There is no one, real, best solution. The best way to handle the situation will be compounding multiple methods to ensure that all bases are covered.
This article will offer ways to go about this:
https://www.gardeningknowhow.com/plant-problems/pests/animals/keep-rabbits-out-of-gardens.htm
I had to cut out a 12x4 foot section of raspberries due to rust fungus. I want to use this space for something productive preferably something that will help fortify the soil against the fungus next year, or a useful companion plant to help my remaining raspberries. Trying to turn lemons into lemonade. The area is south facing 4-6 hours of sun per day zone 7B (PNW).
You can, pretty much, plant anything else that isn't related to raspberries in that area. All rusts that affect raspberries and blackberries will be a permanent installment in the soil, and no treatment will kill it off.
Here is an article that will help:
https://www.gardeningknowhow.com/edible/fruits/raspberry/treating-rust-on-raspberries.htm
Now is spring; they are leafing out. I've removed all spent canes recently (last year's bearers). But what remains are largely lying on the ground as my inadequate trellising was collapsed as well by snow. Many canes are broken near the ground - canes which would be this year's bearers if they could be saved. How can I best deal with this situation?
So sorry to hear about your snow disaster. If the canes are broken at the ground they absolutely need to be removed because they are vulnerable to all kinds of problems. You may have to start all over again with your raspberry crop. Here's an article that may be helpful:
https://www.gardeningknowhow.com/edible/fruits/raspberry/pruning-raspberry-bushes.htm
Here is a photo of a bug and I don’t know what it is. It seems to be stuck to the leaf of the raspberry plant. Can you help identify this please
That's a ladybug pupa! Leave it there. They are very beneficial to your plants, and will eat pests that will cause harm to your garden.
I’m looking for recommendations or advice on treating my new raspberry shortcake bushes. They were nice and green when I brought them home and now the leaves are turning yellow and dying off. It is only happening on the old canes and they are still producing fruit beautifully. I suspect I was overwatering them so we have completely cut back watering to once a week. They are in containers and not the ground yet so I’m assuming they need to be watered more frequently then established plants. Should I leave the yellowing and dying leaves or remove them? Add nutrients to the soil? I have five bushes and it is happening to all of them. Help!
Yes, I do see signs of overwatering.
Instead of watering on schedule, try watering when the container needs it. Once the soil dries down to about 3 or 4 inches, give it a nice deep watering. This take will vary depending on the climate conditions at the time, so measuring is important. Just stick your finger down to the depth of 3 or 4 inches and if there is any moisture at all... Hold back on watering. Alternatively, you can get a moisture meter to help.
Treat with a fungicide, then care for them as usual.
Here are some articles that will help:
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
https://www.gardeningknowhow.com/edible/fruits/raspberry/raspberries-in-pots.htm
The raspberry canes from last year will die after early stages of fruit development. The new canes will not develope in time to produce fruit.
Unfortunately, raspberries are susceptible to many diseases that are not curable, and lifelong. This is probably the case here. You can choose to keep the plant around for an ornamental, but it is likely that you will have to find a more disease resistant cultivar, or plant blackberries instead.
Here is an article that will help:
https://www.gardeningknowhow.com/edible/fruits/raspberry/raspberry-canes-turning-brown.htm
I accidentally sprayed the wrong insect spray on my raspberry plants. I immediately used water to get the spray off. Are they still good to eat?
You don't mention what the wrong spray was so I can't look it up. If you read the label, it should tell you how close to harvest you can use the spray and if it can be used on edibles at all. Some products, like Neem Oil can be used until the day of harvest.
If you don't find it on the packaging, call the company and ask, or call your local cooperative extension agent for advice.