I have a neighbor who made a lovely hedge out of a long row of spireas. They have a white flower in the spring and the branches do form a dense barrier underneath. She uses a hedge trimmer across the top to keep them contained, and in spite of my wild & natural leanings, I like the look. Nice hedge. Throw in a Border Collie and those kids aren't going anywhere!

Nothing is going to grow fast enough to beat the three-year-old. By the time that one is 5 or 6, you'll just be able to tell him/her where not to go and you can expect obedience. It will take longer than that to grow a hedge.

That said, if you just want shrubs, rhododendrons and cherry laurels grow reasonably well and flower some in part shade. Not sure about hardiness in zone 4. Or you can simply plant shrubs pretty close together while still allowing their natural shapes to assert themselves.

In the swampy area, you could plant any of several types of clumping, spreading dogwood relatives (cornus sericea, maybe, or cornus alba) that tolerate damp soil. Rosa palustris is also native to damp soils. Actually, anything with "palustris" in the name will take damp or seasonally wet areas. Many willow relatives like damp soil. You can get some native plants sometimes extremely cheaply from your local cooperative extension or soil/water conservation authority as they are used for stabilizing streambanks and wetlands preservation projects.

Privet won't grow in zone four? Of course, privet needs sun. There are some boxwoods that are hardy to zone four, I think.

But it's true that by the time you have a lovely hedge to keep the kids in, you won't need a hedge to keep the kids in. The part where they're little seems long but it's really a fleeting thing.

Nothing wrong with a hedge, of course, but it's not going to help with the kids you've already got. Maybe a future kid?

As a rule of thumb (for what it's worth)...when you look at a nursery tag and it says something like..."Grows to 8' tall & 5' wide). Those are based on 10 years worth of growth. That is sorta the industry standard for "maturity" of a shrub. So, the above posters are correct in saying that your kids will grow much faster than your hedge! :)

Some rugosa roses might do the trick rather nicely. They'd grow quite quickly, they're mostly disease free, and flower beautifully. And the little guys wouldn't be able to squeeze past too easily.

And then there's that temporary wire fencing you just push into the ground you might put up, letting the neighbours know that it's just a temporary measure to corral your little ones. I've got some that's about 2.5 feet high.

Thanks for the great suggestions! (I thought I had this thing set to send a notification to my email when I got responses, but that didn't happen...) Yes, yes, I know - he'll grow faster than they will...but I'll look into these and see what I can do as far as spacing and the intimidation factor (I wasn't crazy about a thorny hedge until he informed me he didn't need thick gloves to pick up those rose branches I'd just trimmed - his new knowledge keeps him the heck away from the roses, so I'm thinking I'll reconsider)

I'm really excited about looking at those suggestions for the wetland border, too.

thanks!

The only thing I can think of that grows quickly and would keeps kids in would be meidland roses. They are grown on their own roots and are very full but only get about 3feet tall as they are considered shrub or landscape roses. They have thorns that keep people out.