Marigold seeds can be frozen in a MOISTURE proof container. Make sure your marigolds seeds are completely DRY. Marigolds need to be scarified before germinating so keeping it in the freezer is a good option. But i am not sure how long you can keep them in the freezer...

DO NOT freeze you nasturtium seeds in the freezer or they will die. To store the seeds make sure they are completely dry, put them in paper envelopes, put the envelopes in a air tight container, and store in a cool dry place.

Cara

This post was edited by Silva-Moon on Tue, Nov 18, 14 at 3:41

I presume you mean freeze on the bush? With marigolds, that's not much of a problem. You can gather and store.

As far as nasturtium, the seeds on mine outside went through a fifteen degree (or colder) period last year in that awful winter and volunteered plants all over the garden. I was weeding those things out and my problem is keeping numbers down and the plants under control! Freezing isn't recommended, but doesn't seem to be much of an issue...

I tend to believe that if the main plant can survive a winter then the seeds will too. There are some that survive colder treatment than the main plant will.

Hi, All seeds that are DRY stored can be frozen. If your seeds were completely mature and the moisture is low enough, the freezing temps will not hurt them at all.
There are a few seeds that most be fresh sown and can not be dry stored like citrus for example, those kinds of seeds can not be frozen.
But most seeds are dry storage type, so they can be frozen for long term storage. This includes hot climate type seeds like tomatoes and peppers(Freezing is not necessary for regular seed storage. A cool, dark, and dry spot will keep most seeds good for a few years.) When storing seeds in a freezer though, you must let your container come to room temp before opening or you can kill the seeds.
For anyone interested, here's a link about the Svalbard Global Seed Vault in Norway which is inside a mountain to keep the seeds permanently frozen until needed.
Remy

Here is a link that might be useful: Svalbard Global Seed Vault

I know that seeds differ as to freezing. also as to dryness. the weeds I have don't seem to care about either. also , I live in farm country and see the farmers battling volunteer corn in their soybeans yearly. i don't know of any list of seeds and their cold tolerance. I do know that dry seeds for the most part will keep very well in a cool spot. I also know that weed seeds wait in the ground for years until they are at the right depth to germinate. they also endure freeze and thaw many times

I know this is old, but I was curious about the idea that nasturtium can't be frozen. I winter seed these every year, usually quite successfully. So maybe the answer is that you don't want to put them in the freezer, but allowing them to freeze and thaw *in soil or coir* will naturally scarify them.

Nasturtiums don’t need stratification (or scarification, which is different) because they are native to climates which do not have cold winters. They are perennials which grow year round. Any temp below freezing will kill the plant and any green seeds. However, as remy said 7 years ago, the seeds will survive below freezing temps if they are mature and dry. If still green and juicy they will freeze to mush.