Should I be worried about cold snaps affecting my sugar maple seedlings?

Question

I have tried growing maples and this is my fifth attempt. I started vermicomposting in May of this year. It is direct vermicomposting (earthworms in the pot, and feeding them in the same pot that I will grow my tree in).

I first started with batches of vegetables without any leaves to cover them up. For several months I did this until the smell became not as strong as ammonia but definitely nitrogenous. Since then I've added batches of already fallen leaves. I haven’t given them wood at all, just scraps and leaves. I continued adding batches of carbon rich leaves until now. I tried adding nitrogen again but I got that nitrogenous smell again. I have only aerated the soil once because of the worms.

I have a mature sugar maple seed in the freezer to stratify (mimicking winter). I have had it in there since June or July.

I plan on planting it on March 21st when I know it is spring. But I am a bit worried about my maple. Cold snaps happen here in March and sometimes it extends all the way out to the end of April. But March is the best time to plant the maple. I know maples are cold hardy (and heat hardy as well, we have hot summers here, up to 100+). But I would still be worried about a tiny little seedling in a cold snap.

I once had 2 trees that survived for 3 years (I planted them from seed in 2012 I think) but that third winter was bad for those trees. My trees kept getting wounded in the winter. I used tape like a bandage but after those wounds healed, there were more wounds and all these wounds drained the life out of the little trees. How did I know? No leaf buds even in May.

The reason I am worried about cold snaps is because I know that at least for some plants, cold snaps can cut off seedlings from their roots due to the cold weather.

Should I bring the pot inside in March and then plant the maple inside by the back door (it is a sliding glass door with a screen door) so that it can get sunlight without worrying about the cold? The pot is big, definitely big enough to hold a tree for at least 3 years.

I can tell my maple apart from weeds even as a shoot. My maples have bigger baby leaves than the weeds.

The kind of maple I am growing is a sugar maple. So should I bring the pot inside and plant it in March or should I just plant the maple outside in March where the pot is now (in a sunny spot on my patio)? In either case in February I plan to get the seed out of the freezer and warm it up before planting it from seed in March.

Answer 1

You should plant your sugar maple seeds outdoors, straight from the freezer, in March as you intend - they will germinate and grow when the time is right. In fact, as its seed, you could plant them now and leave them outdoors, if most your winter is below freezing - sitting in frozen soil in a pot isn't much different from sitting in a freezer indoors. The thing to avoid is the potting medium freezing after germination has taken place and you have an actual seedling, so some protection round the pot to insulate it if the temperature falls below 0 degC day and night for a week, or removing it to a cold greenhouse or cold room indoors until the cold snap passes, is appropriate. If you want to stand the pot/s near the house wall, or in a sheltered, sunny spot to decrease the risk of freezing, that's fine.

It's not clear what relevance the vermicomposting paragraph in your question has to growing sugar maples - it's not a good idea to plant the seed/s straight into that, if that's what you're thinking, the nutrient content will be too high for a seed or seedling, you'd be better off using a proprietary seed and cutting potting compost. When the tree is large enough, plant into the ground - keeping it in a pot permanently as it grows will make it more susceptible to both cold and disease, and these are large trees which won't appreciate being contained for any length of time. More information about these trees here http://maple.dnr.cornell.edu/pubs/trees.htm

UPDATED ANSWER

In response to your comment, your vermicompost can be added to potting compost, but it should not be used as a planting medium on its own. Some information regarding how to use vermicompost in pots here http://www.vegetablegardener.com/item/14703/how-to-use-vermicompost-on-your-plants

In regard to keeping your sugar maple in a pot, it will be okay in a pot for probably a year, maybe two if you pot it on into a larger, deeper pot as time goes by, and add your vermicompost as appropriate to provide nutrients. On the subject of nutrients, too much availability is just as much a problem as too little, but equally, insufficient root room will cause significant problems with plants, and ultimately, death, particularly plants that should be growing larger quite quickly. Any longer than 2 years in the same pot, and the sapling will start to suffer, so it rather depends when you're moving as to whether it'll still be a viable plant at that time.

Answer 2

Rule #2308 Never transplant/move a plant from indoors to outdoors without 'hardening off' first.

I would try to transplant these baby maples in 1 gal. pots. Using purchased bagged sterilized soil, use a spade to collect as many roots with their soil intact and as undisturbed as possible. Put the soil that came with the roots into a depression in potting soil (not garden soil), firm the soil again around the baby maple and water. Keep in your garage. You should have a few survivors starting at this late date and next year a bit of fertilizer. Hole at the bottom of the pot, no gravel or rock below the soil in the pot, only bagged, sterilized potting soil. This is for a cold garage, not a heated garage. They don't need sun during dormancy, just stable, above freezing temperatures/lighting. You will have to acclimate your plants from the outdoors to indoors over a few weeks. Bring indoors for a couple of hours then back to their normal spot. Do this for 3-4 days, then bring in for 6 hours and replace in its normal spot. Do this for 2-3 days, then 12 hours indoors back outside for 12hours...for 3-5 days, then keep inside for 16 hours for 3-5 days...by then your plant should be acclimated. It would be best to stretch this out for a longer period of time = less stress.

These trees are deciduous meaning they lose their leaves for the winter and go into a sleep like a bear. Not really at all like a bear but the idea is similar. You don't want sunlight and warmth unless you've got a greenhouse.The longer the transition from outside to inside and in a pot (the same reversed) the better. Do not overwater, do NOT fertilize! They are going to go to sleep, not a war, grins.