Humble newbie worried about his pine and spruce seedlings


I was recently gifted a bonsai growing kit as a birthday present and got a couple of seedlings from the kit. Image below are some of my Pinus Aristata and Pinus Thunbergii all between 2" - 4" in height. (Not pictured: Picea Mariana)

Before I get to my questions I want to mention that after my initial excitement of getting my first seeds to germinate, I scoured the internet for ways I can ensure my seedlings stay healthy. In doing so, I’ve come face to face with my naivete and have learned that:

  1. seed starting bonsais is a pretty bad idea
  2. pinus aristata are not meant to be grown in my zone (PNW, 8b)
  3. I sowed these seeds pretty late in the Spring (May 9th)

With that said, I am unreasonably attached to these little guys due to my uncanny ability to anthropomorphize anything and everything. I want to do my best to keep these little guys alive.
Here are my questions:

  1. Can I keep my seedlings indoors and under grow light until spring next year, moving them into a garage that stays between 25-45 degrees during the winter? According to this similar post last year, this could be okay. I am concerned that these seedlings will not have enough time to grow and establish themselves to face even a mild PNW winter. Temperatures don’t drop very low, but I’m concerned about what the amount of rain we get here during the winter will do to the pines.

  2. Would it be better to let them outdoors in the summer/fall and take them in the garage during the winter? I’m aware that bristlecones do not like lots of moisture and hot weather; fall is very wet here and lately we have been getting around a max summer temp of 95 degrees.

  3. Along those lines, is there even any hope to keep a bristlecone alive here for any significant amount of time in 8b?

Responses to my questions, or any general advice to keep these seedlings healthy is much appreciated.


I would move the seedlings outside , adapt to the full sun slowly and allow them to grow outside.
For the winter I would place beside the foundation and mulch around the pots, make sure they do not dry out over winter. but water only when temperatures above freezing.


Hi Frank!

Just so I get a better understanding, the reason your advice differs from this post is because there is enough time until winter in my location for the seedlings to establish themselves and survive the low temps? Where as in that post, the user did not since they posted in September?

Another question: should I bury them in the ground? Or is it fine to keep them in their pots and just bury the pots below ground level?

Do my bristlecones have a good chance surviving the moist PNW fall/winter?

Yes, the circumstances are the opposite! Now is the beginning of the outdoor growth cycle, lots of time for adaptation and growth. Plenty of time to adjust slowly to cooling temperatures to prepare for winter and dormancy!
I have no experience with bristlecone pine, however one can adapt the location if excess rain is considered a problem. Under some protection. Temperature will be buffered by location close to a foundation of a heated building as well. The pot can be set down in the soil, just ensure that there is proper drainage so water does not pool in the container. I prefer to mulch up around the sides for insulation rather than bury in the ground for that reason.
You are the best judge of the opportunities that present themselves in your location!


Awesome, thanks for the clarification!

As for protecting the bristlecone pines, would a simple clear cover (that doesn’t restrict airflow) be suffice to ensure the soil doesn’t get too moist?

I’ll go with you above ground mulching approach. What kind of mulch do you use?

Again, thank you for sharing your knowledge!

For rain cover it is sometimes enough to place under an overhang or eve on the house or garage! These areas typically get less rain, at least from some directions. For example most of the storms come in from the west on my site, making the eastern side of the house and workshop drier zones.

Mulch can be any number of choices. I will often use leaves raked up in the fall, or pine bark. I prefer something lighter that is easy to shift or remove. The purpose is to provide some insulation. I tend to stay away from things that would soak up too much moisture and freeze solid!
Hope this explanation helps. The principal is insulation from heavy temperature swings and to trap some warmth from the ground near a foundation.