Seeds of several Western Pines

[Marc Wiehn]

Yesterday I received seeds of several western pines I bought online. I bought lodgepole, whitebark, jeffrey, limber, and sugar pine. Should I sow the seeds now and put the pots outside, protected against rodents to get stratified over winter? Or should I just wait until mid March and sow them then? This is my first try with western pine seeds.

I am in Indiana, zone 5b, our winters are usually cold and snowy.
Thanks!

 

[jeanluc83]

I have only grown Pitch pine from seed but I stratified them in the refrigerator with good results.

 

[Leo in N E Illinois]

I would. They all will have more uniform germination with a cold stratification. The advantage of sowing outside is they won't sprout until the weather is warm enough to be outside. You don't have to monkey around trying to give them bright enough light indoors.

The Whitebark, Limber and Sugar pines are 5 needle pines. The flats with these seeds you should not disturb for 2 years. Some seedlings will sprout the first growing season, some will not sprout until the second growing season. The reason is that 5 needle pine will have a portion of their seed will require a warm stratification, though a portion usually will germinate immediately. The percentage of seed that will require a warm stratification I believe is driven by the moisture content of the seed during its storage. The drier the seed got in storage, the greater the percentage of the seed sown will need a warm stratification. This is very similar to the requirement for sprouting Japanese maple seed. Fresh moist seed will only need one cycle of cold stratification, where dry seed will need a cycle of warm stratification in addition to the cold stratification. So for these, just keep the flats undisturbed until the the middle or end of the second growing season to get all the possible seedlings to sprout.

The Ponderosa, Jeffrey, and Lodgepole pines could be sown in March, with fairly good result (better than 50%), with some stragglers. Or they could be stratified by autumn sowing. I believe the cold stratification can be pretty short, maybe only 60 days, so if you sowed these in February, that should be plenty of cold outdoors to get good germination when it warms up the end of April.

I've been somewhat haphazard in my handling of seed, but I have started many species from seed, including Sugar pine and Jack pine. Jack pine is closely related to Lodgepole.

Dry seed of Ponderosa, Lodgepole, and Jeffrey pines should store well for many years, (something like 5 to 10 years still above 50% viable) plant some, and reserve some for later trials. The seed of most 5 needle pines looses germination ability fairly rapidly. Most white pines (5 needle pines) dry seed will be at less than 50% viable within 18 months. Fresh seed is important for the white pine group of species.

Hope this helps.

 

[Leo in N E Illinois]

Pine seeds are good squirrel, mouse and bird food. Definitely cover seed outdoors with screen, wire mesh or hardware cloth.

 

[Marc Wiehn]

Great advice, all! I will probably sow them now, and let nature takes its course. In your experience, is any of the pine species listed not suitable to use the seedling cutting method on? I am especially wondering about the whitebarks (P. albicaulis). So after they have sprouted to cut off the tap root and force them to develop a new root system closer to the growth point?

 

[jeanluc83]

I would try a few of each. I have only used the technique on pitch pine but found it to be worthwhile. The root distribution was much better on the cuttings. The interesting thing that I found was that the development of the cuttings vs the non cuttings was almost identical. I lost more of the cuttings vs the non cuttings but that was mainly due to them being disturbed before they had rooted.