It might still be a big soon for much pepper growth. And it might be past when broccoli plants do their thing. Did you get some broccoli from them?

Oh boy. Well, asparagus is a perennial and it does not like it's roots to be disturbed at all. For that reason, people don't typically interplant it with annual vegetables where you intend to plant and pull and turn the soil on a regular basis. You also realize it can be several years before you get any actual asparagus to eat, right?

Secondly, your broccoli died because it's not a summer vegetable. Search the internet for vegetable planting calendars in your city or county. They are an invaluable tool that will tell you when to plant. All vegetables are not on the same schedule.

As for that Mel's mix popular with square foot gardeners, lots of people are in love with it, but IMO it's just potting mix that needs to be watered too much and doesn't provide enough nutrients. If your beds are over the native soil (i.e. you didn't put a block down to prevent the roots from accessing the soil beneath them), I tend to favor a top soil/compost combination that compacts better, will retain moisture. That isn't going to help you this year, but maybe in future years. As for this year, you will have to keep watering frequently and fertilizing to keep your plants healthy.

I suspected maybe it was too early for the peppers, but the tomatoes are thriving. Don't they do similarly?

The asparagus was in my first attempt at a garden last year (I found I didn't get enough sunlight, so I moved it). I kinda didn't expect the asparagus to survive replanting, but it has done well. It is over to one side, so I hope the roots won't be too disturbed.

Everything was planted as plants about 2 weeks before the last frost. (I had to cover them a few times, and everything did okay). I have since put in some basil and lettuce seeds and they are doing well.

I did not get any broccol flowers. It did okay for a couple weeks and then started to die. I planted it as soon as plants were available (2 weeks before the last frost). Is that too late to get a crop?

As far as broccoli goes, it is thriving here...huge heads.

I'd suggest the possibility of cabbage root maggots just because I got them this year. Cutworms may have gotten the transplants, too.

If everything else is thriving and one crop fails, first thing I think of is a malady specific to that crop.

Re the peppers, I didn't have much luck with them until a neighbor told me a) plant them close together--leaves touching if they're decent-sized young plants--and b) peppers need lots of water.

Roccoli could grow in the su mer in ny, I t needs lots of water though a dnutients. It might not be dead, water and cut off brown leaves.

Roccoli could grow in the su mer in ny, I t needs lots of water though a dnutients. It might not be dead, water and cut off brown leaves.

My best guesses are:
Broccoli: root maggots
Peppers: shallow rooting due to frequent watering. Water deeply and infrequently. Let them get almost to the point of wilting before watering again. They also need warmer soil than tomatoes. Tomatoes can manage soil in the 50s and are happy with soil in the 60s but peppers need 70s.

I've found my local cooperative extension to be a very good resource on planting dates. I found similar information online from Cornell University, which might not be local enough for Toller1, but it could give you a general idea. I'm attaching the link, which I hope is useful. They also have a chart for Late Planting Dates, to give you an idea when to plant fall crops.

Here in MD, I plant early spring crops like broccoli, cabbage and lettuce more than a month before I plant main season crops like tomatoes, peppers and eggplant. Broccoli is kind of fickle for me, and if it doesn't have enough time to grow before it gets hot, it may die off before I get much of a harvest. I've also found that I have much better luck with the hybrids than OP varieties. I'm an organic grower and some of the organic hybrids can be very expensive, but it's worth it.

Here is a link that might be useful: Cornell University Planting Dates

Actually I am exactly the same as Ithaca. Thanks.
But it says I planted correctly, so I am not sure what the problems is.
I will take a picture of my broccoli. Maybe that will help. They don't actually DIE, but the leaves wilt.

Wilt does suggest root maggots.

A growing guide is just a starting point...
Broccoli is a cool weather crop, meaning cool soil. You can help keep the soil cool by mulching and watering deep, not every day. May buy a bit of time but sudden hot weather like we are having right now and the past few weeks, hot/then cold, will pretty much toss planting guides out the window.
Not every crop will do as planned every year...
I had great broccoli, cauliflower, broccoli rabe, and hearty greens a few years ago but a bust the past few...too hot too soon.
Some crops do great every year no mater the weather...
Peppers like this weather but may not have liked going in so early. Mine have only been in two weeks now. I let them be until i see flowers, then start feeding....
With so few varieties, study the needs of each plant. An all-for-all soil mix does not exist.

Asparagus really wants to be off on its own. If you like it where it is, you might want to add a division board so it can be left undisturbed and mulched separately. If it does well, the summer fronds will get dense and 4-5 ft tall after a few years. May even shade you veggies.
Though that can sometimes work to an advantage. Get a compost pile going if not already...next year your soil will thank you for it. Fresh bags of this and that in a new bed are often not so great...just seems like it should after the sticker shock...

Root maggots - I dug up one of the plants. The roots are solid, but very small. Either something is damaging the roots, or the same thing is damaging both the leaves and roots.

Peppers - The plants are very small, but they are flowering and there is even a tiny pepper.

Asparagus - They are on the north side of the garden (about 30" wide by 15' long, running N-S). I can put in a partition this fall.