Nasturtiums are wonderful reseeders! My garden has them just about everywhere this year, including one really enormous patch which is blooming already, all from reseeding... and I even collected loads of seeds off them last year and STILL there were tons left to sprout this year. It's one of my favourite plants though, so I don't mind. I pull out the ones in my way and let the rest grow (to reseed again!). If you have soil/earth below your window box you might end up with lots next year.

Newskye,
yes, there is some soil (part of the flower bed) under the window box. I love these happy flowers. Their colors are just gorgeous! Hopefully they will survive in our zone 8 (it has been zone 7b till recently), and the next year we will be seeing much more of them.
They kind of taste like radishes, flowers and foliage. Cool!
Thank you for your response Newskye.
~Natalie

We don't consider our garden salads truly "at their best" until they include nasturtium blooms of all colours!

They are reseeders, alright!

I deadhead until September and then let them do what they want so I get some self-sown next year. Here they are not heavy reseeders. I kind of wish they were.

I wonder if they are better reseeders in zone 8. If I do not dead-head them, most of them form the round seed ball. Have not seen them drop the seeds yet. Since this is my first year planting them, I look forward to see what happens next year with the seeds from the mother plants.
Love it when my flowers multiply and I become a flower grandmother :-).
How often do you fertilize them?

Here's a pic of my reseeded nasturtiums this year! They're crowding all over each other, and I didn't plant any of them. (wouldn't it figure, those orange flowers right next to the pink roses!)

{{gwi:11751}}

Beautiful! So abundant and carefree - just gorgeous!
Thanks Newskye.

I garden in north and south, and my joy was finding out that nasturtiums liked it up north. I have a monstrous fat row of them running 100 feet down the driveway, and I did not buy any seeds this year. I collected all the seeds off the ones I put out LAST year, and that was a bumper crop. I left some seeds out, but nothing had come up as of mid-May when I planted the seeds I'd collected. I don't put this out as a scientific controlled experiment, just an observation. It was probably too cold up here for the self seeding to work right.

However, I've kept baskets of nasturtiums down south and they never lasted long. I was diligent in deadheading, but they went to seed fast. I'm told they like poorer soil, and cooler climates. Our summers in Alabama are really humid and hot.

I have a problem with my nasturtiums because of all the rain up north this summer, and I will begin another thread to ask about this problem.

That must be it: too much of TLC :). My motherly tendencies...
Thanks, I will let them be and stop feeding them.