Rule of thumb for knowing which seeds need to be kept cold?

Is there a rule of thumb for knowing which seeds need to be kept cold?

moderator's note: added a more descriptive title to topic

 

Are you thinking for storage or for germination? for storage all seeds should be kept cool and dry. If you need stratification answers that is different. There are seeds that should be exposed to cold and damp in order to germinate.

 

Carolyn, I meant stratification. Just could not remember the word.

 

Donna, off the top of my head...dogwood, delphinium(I think) monkshood, alliums, columbine? persimmons, maple seeds, most perennials,... I am sure there are a lot more than this, too. I think if it grows where there is freezing and thawing and it survives that, then it probably needs stratification.

 

Stratification for perennial seeds in a temperate zone allows for a period of dormancy to avoid premature germination. For this reason many collected plant seeds require a cold period. Simulated artificially by a refrigerator or naturally(to better account for temperature fluctuations) outside in a cold area like a garage.

My rule of thumb: All perennial seeds gathered in the yard where the plant successfully winters over are put in a container, marked and put in a seed drawer in a spare refrigerator for the winter. There are some sites that give large lists of seeds and germination techniques/requirements. They are often useful if you are uncertain about days to germination, seed depth, germination temperature, type of media, light/dark requirements etc.


A lot of fruit trees also require what are called chill hours to produce viable fruit. The seemingly endless list includes peaches, apples, apricots, plums, cherry, pears and many more. Some lists include nuts. A chill hour is usually defined as an hour below 45°F. The definition however, is a moving target as there are many opinions about the definition. A local extension service, farm bureau or university may well have more relevant data for your area.

Jerry

 

Most tree (or woody plant) seeds need a winters cold (and wet) slumber.

In a cold house or outdoors.

Mixing up chilling hours needed for malus to bloom (in season) and inhibitors preventing germination of tree seeds is like comparing apples and oranges.

Both happen over the course of a winter.

 

It's important to remember if you're chilling seeds or apple trees, etc the hours that count are the hours ABOVE FREEZING and BELOW 45F. Freezing them solid for the winter and then planting them is not going to do it.

 

Thanks all for the info. Now to put it to use.