I don't know about pumpkins, I think that they take a long time to germinate and a really long time until harvest. Most people I know that are growing them have already planted them (but we are in Arizona and our seasons come earlier).

Sunflowers are great for kids. I planted some in a window box with my 4 year old less than a week ago and they have already sprouted! They need a lot of space (from what I've been told) because they get so big. We're going to transplant ours once they start to outgrow the box.

Good Luck!!

I'd add a few things that mature quickly so he can see the results of his work.
Or things that he likes to eat and are easily harvested by little fingers.
Things that have "cute" names are also good. Like Dragon Tongue Bush Beans.

My grandchildren and I are also planting pumpkins this year. I picked up a planting guide from my county extension service; it recommends sowing April 10-30 or later for pumpkins that reach maturity in 90-120 days.

If you have a seed catalogue you can compare the harvesting times for different varieties. We chose Jack Be Little, an ornamental, (85 days,) and Baby Bear, (105 days.)

I'm still looking for information on seed germination times, if I find it I'll post.

I notice you are in Zone 7 also, hope this helps.

sara

My 4 yr old and I tried pumpkins last year (connecticut field pumpkins - i think!) and they really needed a ton of space and the vines are very prickly. It overtook our garden and was so hard to manage-- we got 2 nice pumpkins though but it wasn't really worth the pokes and tears! No pumpkins this year! But I don't mean to discourage you, just a warning to try a variety that is maybe a bit more compact and try and use a low fence around them so that you can just toss the long vines behind it. My little ones loved growing green beans and picking them for dinner (and eating them off the vine for snacks), carrots were a big hit too. My kids and I go through garden catalogs so they can get a look at different things that are out there and we look at the sun symbols to see if the plants would work in the place we're planning for. Fun garden time when it's still a little to early for us to plant! Good luck!
Jackie :-)

My three year old son wants to grow sunflowers and pumpkins too! And compact plants were what I needed too! So I found 'Jack be Little' which is supposed to be around three feet instead of the usual six feet sized plants. And it doesn't need to be cut into for decorating, just use markers or paint to decorate. Since it takes 95 days to maturity, if you got seeds (I have some if you want me to mail them to you) next week, you could have pumpkins by August, right? What do you think about that?

{{gwi:1271057}}

-Robin

Sugar Pie or any of the pie pumpkins are cute and useful too, but the vines are still big. My 4-year-old wanted pumpkins, but she was SO disappointed with the pumpkin pie -- yuck! We had Jack-be-Little too, you can train them up a chain link fence, or any fence, and that keeps them out of the way. Snack Jack is a pie-sized pumpkin but has fantastic edible seeds. That was our favorite.

Kids can scratch their names or a design on the green pumpkin shell, and it will grow with the pumpkin and be visible the whole time.

Here is a link that might be useful: {{gwi:1271054}}

i too am starting sunflowers and really look forward to the rapid growth they supposedly have(took about 6 weeks to get to the one inch tall seedlings we have now!)
my 3 year old enjoys the peas we row, he picks them off the vine and eats them raw...poor pea plants tho(the vines are very delicate) we also grow grapes and strawberries and they always enjoy that!!

pumpkins grow very fast(well have in my yard) i already have huge plants that i didn't even plant!(we just thre away rotted ones in the area we plant pumkins in!lol self seeding with a hand)i'm worried they'll be mature WAAAAY before halloween! my kids loved watching their pumpkins grow, you could literally see an increase in size each day once the fruit were established. yes, the vines are a little prickly. my kids enjoyed picking their own pumkins and having many available for carving(my hands did not enjoy all the carving!lol) but it's up to you, halloween is special for us so maybe that was part of the thrill of growing them ourselves....
blessed be

Hey a great book on this is Boots, Shoots, & something I can't remember, by Sharon Lovejoy I believe. She's got some great idea on what to plant with kids in it. A string bean tepee, a garden of giants (like giant pumpkins), a pizza garden, etc. There's some good info on what plants are edible too.

I grew one year when I wanted my son off his bottle a cucumber vine. Stuck the bottle up into the young fruit and it grew so it couldn't be pulled out. I told him that was it no more bottles. How did that cucumber get in there?
Try some gourds too along with the pumkins.