I grow Raspberry Rugostar, so I know it definitely produces hips if you have a large population of bumblebees. It was originally a low growing plant, until it got shaded by a wheelchair ramp. It now grows high enough to get enough full sun.

I second the Rugosa recommendation. Be aware that not all of the Hybrid Rugosas are fragrant and make hips, so check those traits on HelpMeFind. One worth investigating is Hansa.

:-)

~Christopher

Therese Bugnet grows tall and is full of thorns. Stems are red so provides some winter interest. It is fragrant but no rose hips.

I'm planting some roses this weekend for the same purpose and am using white dawn - it has the nastiest thorns I know of other than perhaps dorothy perkins, but that's a once bloomer and not fragrant. I have the option of them growing up the sides of the house on either sides of the windows, however, so if yours needs to stay below window height then maybe something shorter/bushier would be a better choice.

Thanks everyone! Off to research. Any particular favorite shrub rugosa varieties?

Pink Surprise Rugosa would deter any break ins.

If you are planting roses for birds, choose some with smaller hips. Squirrels love rugosa hips, since they can pick them up and eat them like we eat apples. Birds don't have fingers, so hips either have to be small enough to eat in one bites (preferred) or rotten enough to be pecked at. Squirrels will usually get to those first.

Moje Hammarberg, scent to die for, hips & very thorny, one of my favourites.

The Rugosas sucker on their own roots, don't they? Roots spread out & throw up new canes in an ever-expanding patch over time. Might want to find a grafted one if this wouldn't work in your space. Thorniest rose I grow is Aloha Hawaii, a shortish climber whose main canes are literally studded with thick long sharp thorns. Can be grown as a stocky shrub with pruning or allowed to frame the window for a double deterrent. Blooming laterals not as bad as the main canes, but no one could wade through it without a suit of armor. Fragrant double blooms in a range of sunset hues that repeat well & often from early to late here. Lovely fat hips if not deadheaded. HelpMeFind says occasional bloom after the first flush, but Member Ratings average out to Good- from 11 feedback reports. Bloom frequency increased with age here to 4-5 flushes at 4 years old. Nippstress grows this in zone 5b Nebraska.

http://www.helpmefind.com/gardening/l.php?l=2.39802.4&tab=1 

Keep in mind that it would be a barrier if you ever needed to exit through that window, though. Sue

Not all own-root Rugosas sucker, I have Moje Hammarberg, Schneezwerg, Fimbriata, Marie Bugnet & Souvenir de Philemon Cochet. In 7 years only one had a small sucker which I dug up & gave to a friend. I don't know if climate & soil are determining factors but I have been improving my soil annually for 7 years.

I grow Rosa Rugosa and Rosa Rugosa Alba. Both are great roses that NO ONE is going to try and get through. Beautiful blooms all season and both set hips after each flower. They both smell great. Beautiful late fall foliage. For me they enjoy a good acidic soil.