i always wanted a fragrant freesia as it is looks great and a few flowers can scent a room.
also, lavender has many uses.
i'd say basil because i am a pesto lover.
i've always wanted a comprehensive herb garden.
peppers are good to keep pests away from other food plants.
i'm just writing off the top of my head.

chamomile can give a reaction to someone who is allergic to ragweed, so that may be something to keep in mind if any of the kids have hayfever or seasonal allergies.

I'd also say basil since homemade pesto is easier than can be, and so cheap if you grown your own. I was amazed how much I got from one little plant that cost less than a few leaves down at the grocery store.

You must be the world's coolest mom. Geez. Will you adopt me?

Hmm I was going to suggest a tepee but you already do that. When my kids were little we had a makeshift Alice in Wonderland garden, where we looked at the drawings in the books and then recreated the gardens and had pretend and real "tea parties" there. That was pretty cool. So if your kid has a favorite book and there's a garden or flowers in it, maybe you could do a loose interpretation.

Mint is super invasive, even chocomint. You might want to keep it in a container. Kids go berserk over lamb's ears, because they're so soft and pettable, so that's a nice thing to have. They grow like crazy but are easy to control and divide. A butterfly garden was always a favorite here too - mainly a couple of butterfly bushes, a flat rock for the butterflies to sun on, tons of mixed zinnias, and a good place to hide and spy on them.

When I was a kid we three siblings had our own little garden behind our house, and while we didn't have a fence, my dad installed a gate near the entrance to our humble little plot. It was just a gate to nowhere, and I'd spend hours swinging back and forth on it. Kids can't resist squeaky wooden gates. Maybe your garden could have one.

Now my backyard is basically totally ignored, because I have teenagers now, and they couldn't care less. But hopefull I planted a seed (groan) and maybe someday they'll take up gardening on their own.

Have you ever grown moonflowers? It is magical to watch them open up in the evening (July-October, more or less).

I second herbs. The kids can plant them then eat them. Also English cucumbers. I can't remember where I bought them but I used to plant a variety that grew about three feet long and the kids loved them. Grape tomatoes are cool because they provide snacks every day. I also second the advice about mint. Plant it ONLY in containers. It took me three years to eradicate it from my lawn. If you have cool springs try sweet peas as they can grow 20 feet high if they have something to climb.

rosemary

Almost forget, a small pond. Just get a plastic planter and sink it in the ground. Buy some cheap floating plants and surround the pond with a few flat rocks, broken pottery and small upturned pots tilted on their side. Bugs, toads, frogs and such will, with any luck, move in.

night blooming flowers would be great.
i want goth to adopt me too.
avoid morning glories as they are not only be poisonous/psychotropic but erode the foundation of your house.
there are good guides about, and i'll post of them if i find them.
figure if you want something that takes routine disciplined care or takes care of itself for the most part. a mushroom or moss garden could be cool, and even though the pond is a fun idea, i'd watch for anything that breeds mosquitos or pests common to your area.
many different plants and borders can be used to make your house less attractive to pests as well, but a good guide of what grows well in your area will be a big selection to play around with on the mental shopping list. and get cutting and samples from neighbors, friends and what's around you.

I like pumpkins. They grow really big really quickly and have cool flowers and then you get to carve them. Actually, one would be sufficient. They are big and they sprawl.

squash. and squash blossoms.
how big is your yard, we should do like the amish and all go plant your yard.
then come back and raid your garden.

"Who are they, mommy?"
"Rabbitat for Hugh Manatee. Don't ask."

I second moonflowers. We have a couple of vines and they are beautiful, and cool to see when we take the dogs out for their last drain of the evening.

As a sidenote, I've always wanted to have an informal international sunflower growing contest! I unsuccessfully tried to grow one by starting it in a small pot and then transferring it outside to a spot that got all day sun. The ants devoured it within days. Any tips?

What a wonderful idea! For fall kid's gardening we planted gourds on the fenceline with my son. Then we made birdhouses out of them. Still have one these many years later.

All of these are wonderful ideas & I have nothing new to add. My kids always liked the various ponds I've put in over the years, and planting & eating their favorite vegetable, which is one reason we always have cherry tomatos and cucumbers, although cucumbers never even make it into the house; they just get munched right off the vine. Gourds are great, but, like morning glories and mint, they'll happily take over. If you do gourds, put up a huge and sturdy trellis that's fairly distant from your main garden (what I plan to do next year, having learned my lesson finally.) Mammoth sunflowers are cool too, those Russian ones that grow to be like 15 feet tall.

Wow! I knew you guys would have great ideas. I hadn't thought about allergies, kellydamnit. Thank you. The kid's pretty hardy, but she hangs out with some cute little wheezers, so I guess the chamomile is out. I like the idea of the moonflowers and the fall garden, since PA summer days can be brutal. Maybe some gourds and some jack-be-littles. Definitely a squeaky gate and some butterfly bushes, now that iconomy mentioned it. I was also thinking maybe some big, colorful Gerber daisies since they look the most like the kind of flowers you draw as a kid. And I may give her some of her own cherry tomato plants. She ate a good portion of our tomato crop right off the vine last year. (Loved 'em so much that for Halloween she dressed up as a "juicy red tomato.")

eth--my yard is about 1.5 acres, so Rabbitat is totally welcome here. (But please don't mention manatees to the wee one. She's been concerned with their plight since our visit to Sea World.)

We've got lots of toad friends, but I'm worried that a pond would draw out the snakes. (Who so far have been kind enough to stay out of my way.)