read the laws on Burning Bush regarding future sales swaping or reproductions as some states have it on a banned item list. As of 2010 Mass is one state stating no more can be sold or traded as of 2011 Excuse the pun here but some garden centers here in Ma got burnt by a bush

Good luck on the rest

1) Plants from seed should be in a sterile medium. While I've never had problems (damping off fungal issues) starting plants in the gritty mix, if you were doing this on a large scale or commercially, I would suggest that you use screened Turface as your starting medium and cover the seeds with 1/8-1/4" of the screened fines. That's what I would advise you to do ....... so I don't get into hot water if you end up with damping off for any reason, but what I would probably do for just a few seeds is just start them directly in the gritty mix & cover them with Turface fines.

2) I would start start multiple plants in a flat & grow them on for a year before planting in individual pots in spring. The exception would be the pines, which can be moved to individual containers in late Jul or Aug.

3) No fertilizer required until plants are making their first true leaves.

4) Mix gypsum into the gritty mix when you make it; there is no advantage to doing this in advance. For the 5:1:1 mix, use dolomitic (garden) lime. There IS an advantage to doing this a couple of weeks in advance IF the soil is moist. It allows the Ca in the lime to complete a reactionary phase while soil pH rises. After the reactionary phase there will be a much greater fraction of the Ca supplied available (residual phase) for uptake.

5) In the gritty mix, the Turface will always soak up water readily & then 'pass it along' by diffusion to the bark component, breaking the barks tendency toward hydrophobia (water-repellency) when it's very dry - so no worry at all with the gritty mix. The 5:1:1 mix can initially be difficult to wet. I partially wet it then mix it several times as I make it. I also start with the peat and lime mixed together on the bottom, then the bark, then the perlite, I thoroughly wet the perlite and bark before I start mixing. Even if the mix isn't thoroughly wetted through, if you cover it with the tarp you're mixing on, or cover the wheelbarrow with a tarp or sheet of plastic, the soil will (by diffusion) be damp the following AM. If you're patient, you can still get a batch of completely dry ingredients to moisten as you mix it.

Al

Thanks to Al and Wesley for the replies. Thanks for the adivce on sterile mediums too. I have typically grown seedlings in Miracle Grow potting soil, mostly peat, with some success, but am looking forward to trying the gritty mix and the 5/1/1 mix.

Oh, forgot to ask last time. I have a couple small trees in plastic pots, started in spring 2009. A Norway spruce and a silver maple. I have them in my unheated garage now, and wondering if they should have been left outside for the winter or if they are better in the unheated garage. I think the soil is frozen now, but not sure if that is good or not for trees in containers.

Any advice?

Thanks.

My advice is to include your state & zone, or a large city near you in your user info so we can answer questions like the one you asked. ;o) Seriously, it really helps those wanting to help to give more specific advice & answers. Where do you live?

Al

Sorry Al, I should have stated that upfront. I'm near Michigan City, IN and we're zone 5/6.

The ground is quite hard but I might be able to dig in it yet with some effort. The garage is not attached to the house and it's unheated w/cement floors. The trees are in plastic pots on a workbench in that garage.

I placed some snow on each container the other day so the trees can get moisture but the soil in the containers is frozen or very close to it.

Just didnt know if it's better to leave trees and shrubs in containers outside or not, or if I should bury them?

Thanks Al.

For the past few years, I've kept many different trees, shrubs, and perennials in containers outside during the nice weather. When winter rolls around and everything begins to go dormant, I move all the potted trees and plants into an unheated garage. I group them all in plastic baby pools, and I water them fairly well before they go into the garage.

The garage is kept closed all winter. In early spring, before the weather stabilizes, I open the garage doors during the day to let the light in, and I close it before it gets dark. As the weather does stabilize, I move all the pots back outside for another season of growth.

Granted, I'm about a good zone and a half south of you... we presently have no snow on the ground, and the weather has been shifting from unseasonably mild to freezing cold. I've got all the potted trees, shrubs, and perennials tucked away in the garage for winter. As soon as we get some snow, I'll bring a little bit in and throw it on the pots.

Most of our potted plants outside are actually for sale, so if we lose a few, it's not that big of a deal. (We have a small hardy rose and unique perennial business we're starting.) I will say that the amount of plants that break dormancy and grow again after being closed within an unheated garage is pretty high. We haven't lost that many plants, at all. I'm actually rather impressed by the number of potted plants that survive and thrive doing things this way.

Burying potted hardy plants in the garden, and mulching them good, is another way to keep potted plants over winter... but I have too many to use this method. Banking in bare root trees and perennials might be another option... digging a small ditch and laying the trees in it, then covering the roots with soil and a layer of mulch. But again, it's easier for me to just bring all the pots into the garage, place them in baby pools, and wait out the winter.

Good luck with your potted plants!

I have around 200 temperate trees & shrubs in pots, & I over-winter all but a very few on large tables in the garage, also. If I had only a few plants, I would choose to bury those hardy to my zone or colder in the gardens or beds, those hardy only to one zone warmer than mine would still be buried, but against the foundation of the house on the north side.

Al

I'd probably do the same if I only had a few pots... but I have tons!

They're dormant, so they don't require light or warmth or massive amounts of water or feed... they just require protection from the burning cold winds and really low temperatures that could harm the roots in the pot.

The wall of a pot... even a thick one... isn't enough protection from zone 5 or less winters.

Thank you Al and jodik. Your responses are most helpful.

So it sounds like my small 1-year old tree seedlings will be OK over the winter in my unheated garage. I was afraid the container soil, and the roots, would freeze into a solid block of ice and kill the trees. Based upon your replies it sounds like the trees and their roots won't mind the cold too much, especially if I keep a bit of snow on them occasionally for moisture if the temperature rises above freezing (32F) in there.

There's only a few of these trees, all local to my area, so if necessary I think I can still bury the containers in the ground. The ground is hard but not entirely frozen just yet.

Another reason for housing the seedlings in the garage was to keep them away from hungry critters like mice and rabbits. We have quite a few of them around and I thought plants might be safer inside the garage.

Thanks again.

About cold-hardiness & freezing ..... it may seem slightly off-topic because it's a copy/paste job from something I left earlier:

Commonly, each species of plant has a general range of cold-hardiness. Within species and cultivar, cold-hardiness is genetically determined. That is to say that a plant that is propagated from cuttings or tissue culture will have the same ability to resist cold as the parent plant. Plants cannot "develop" a greater degree of cold-hardiness by repeated or prolonged exposure to cold, even after 100 years (trees).

If we pick any plant at random, it may or may not be able to withstand freezing temperatures. The determining factor is the plants ability to prevent freezing of bound water. Bound water is the water inside of cells.

There are actually three kinds of water to consider when we discuss "freezing". The water held in soil - When this water freezes, and it can freeze the soil mass solid, it doesn't necessarily kill the plant or tissues. Then there is free or unbound water, also called inter-cellular water. This is water that is found in plant tissues, but is outside of living cells cells. This water can also freeze solid and not kill the plant. The final type of water is bound water or intra-cellular water. If temperatures drop low enough to freeze this water, the cell/tissue/plant dies. This is the freeze damage that kills plants.

Fortunately, nature has an antifreeze. Even though temperatures drop well below freezing, all plants don't die. In hardy plants, physiological changes occur as temperatures drop. The plant moves solutes (sugars, salts, starches) into cells and moves water out of cells to inter-cellular spaces in tissues. These solutes act as antifreeze, allowing water in cells to remain liquid to sometimes extremely low temperatures. The above is a description of super-cooling in plants. Some plants even take advantage of another process to withstand very low temps called intra-cellular dehydration.

The roots of your trees can stay frozen for extended periods or go through multiple freeze/thaw cycles w/o damage, so long as the temperature does not fall below that required to freeze intra-cellular water. If roots remain frozen, but temperatures remain above killing lows, dessication is the primary concern. If the tree is able to take up water, but temperatures are too low for the tree to grow and make food, stored energy becomes the critical issue. Dormant and quiescent trees are still using energy from their reserves (like a drain on a battery). If those reserves are depleted before the tree can produce photosynthesizing mass, the organism dies.

There are a number of factors that have some affect on the cold-hardiness of individual plants, some of which are length of exposure to seasonal cold, water availability (drought stressed plants are more cold tolerant), how recently planted/repotted, etc.

No one can give a definitive answer that even comes close to accurately assessing the temperature at which bound water will freeze that covers the whole species. Unbound water is of little concern & will usually freeze somewhere around 28*.

Some material will be able to withstand little cold & roots could freeze/die at (actual) root temperatures as warm as 25-27*. Other plants may tolerate much colder actual root temperatures - as low as 10*. There's just no way of knowing unless you have a feeling for how cold-tolerant the genetic material the plant was derived from might be, and finding out is expensive (from the plant's perspective). ;o) Another example of this genetic variance is that trees found growing and fruiting well closer to the equator need no chill time, while other trees, derived of genetic stock from a more northerly provenance may need a period of chill to grow with optimum vitality in the subsequent growth period/cycle.

It's wise to remember that root death isn't instantaneous at one particular temperature. Roots succumb to cold over a range of chill with cultural conditions affecting the process. The finest roots will die first, and the slightly thicker and more lignified roots will follow, with the last of the roots to succumb being the more perennial and thickest roots.

Since any root death is a setback from an energy allocation perspective, and root regeneration takes valuable time, it's probably best to keep actual root temperatures in the 25-40* range as long as we can when the tree is resting, even though the organism as a whole could tolerate much lower temperatures. Even well established trees become very much like cuttings if all but the roots essential to keep the tree viable are lost to cold. Regeneration of roots is an expensive energy outlay and causes the trees to leaf out later than they normally would and shortens the natural growth period and reduces the potential increase in biomass for the next growth cycle and perhaps beyond.

Al

Thanks again to both Al and jodik for the great answers. Based on that long reply from Al I guess it's OK to leave the container grown trees in the unheated garage over the winter. Since all are native to my area they should be OK. I just wasn't sure what would happen to the roots in the frozen container soil. We'll see what happens.

Also thanks for the advice on the sterile growing medium for seedlings. I will give that a try this spring and start my new shrubs and trees right this year. No more prebagged peat-based potting soil for me...

Thanks again. You guys are great!

Kerwee

Thanks again to both Al and jodik for the great answers. Based on that long reply from Al I guess it's OK to leave the container grown trees in the unheated garage over the winter. Since all are native to my area they should be OK. I just wasn't sure what would happen to the roots in the frozen container soil. We'll see what happens.

Also thanks for the advice on the sterile growing medium for seedlings. I will give that a try this spring and start my new shrubs and trees right this year. No more prebagged peat-based potting soil for me...

Thanks again. You guys are great!

Kerwee

No problem. I think the important thing is protecting the root area from the frigid, burning winds. The wall of a pot isn't enough protection, alone. That's why keeping the pot inside the garage will work fine.

Be aware, though, that mice like to come in from the cold, too... and they may come inside your garage. I always throw a few packets of Hawk brand rodent poison into the corners of garages and sheds for the winter... just to be sure.

Thanks Jodi. The garage will protect the plants from the frigid wind for sure but not the cold temps. I guess the soil in the containers would be frozen even if the containers were buried outdoors. At least there is no wind to contend with inside the garage.

Already have some mouse poison down, so mice should not be bothering the plants.

Thanks again for the advice. What a great community!

The cold temps aren't what really damages, I don't think... trees and perennials planted outside would get that anyway. But they have the insulation of the ground and of blown in debris, or mulch, to protect them... it's really the winds and windchill that are damaging.

Al can explain the science behind it... all I know is that a container wall is not enough protection against the burning cold winds of our frigid winters, for the roots. But the stable environment inside an unheated building works. Yes, it's cold... but it's not fluctuating drastically, with those nasty winds and winter sun, etc.

I'll stop before I put my foot in my mouth. Al's the science guy! :-)

I have been watching trhis post and learnig a ton..In fact I myself have plants in my unheated garage now because of this info..

Thankyou!!

I just have one question?

Are we to keep the roots in our pots from thawing and refreezing? Will this be detremental to the plant?

The temps in my garage can get down into the teens, then go up to the 40's on any givin winter day...

Thanks alot!

Unless there are specific questions or something needs further explaining, I think most of what you need to know about the practical side of what drives cold-hardiness is in my longer post upthread.

Mike - it doesn't matter if roots freeze/thaw a hundred times over the winter, It's not the freeze/thaw cycle that kills roots, it's that single trip to temperatures below those the plant is genetically programmed to tolerate that kills the plant (or tissues). IOW, it's killing lows, not freeze/thaws. As long as water inside of cells does not freeze, the rest of the water in the plant (water between cells and in the soil) can freeze solid with no ill effects.

During the winter I used to cut all the firewood to heat my home. I usually picked the coldest days, so the wood would be frozen so solid it split with remarkable ease. It would be full of ice you could see, and the ice crystals would just glisten in the cold sun, but all the trees left standing just picked up in spring where they left off in fall ...... Roots aren't as cold-tolerant as shoots, but you get the picture.

Freeze thaw cycles CAN heave newly transplanted plants out of the ground before roots are well-established where they can be damaged or killed by the effects of dessication, but that is much more common in in-ground plantings.

Al

Are we to keep the roots in our pots from thawing and refreezing? Will this be detremental to the plant?

Generally speaking, no. The freeze thaw cycle is mostly detrimental to in ground plants with shallow root systems that may be heaved out of the soil entirely.

The only exception I can think of would be with cold hardy succulent plants. These plants will survive just about anything other than being both cold and wet at the same time. The freezing wouldn't be a problem, but the thawing and thus availability of water while temps are still cold would be.

Thanks guys for everything..

Have a splendid weekend, and stay warm..:-)

Ya, right, Mike! It's freezing out there, and the wind is blowing and the snow is swirling! I hate winter! :-)

I wish it was spring already!

Frost heave is something I've experienced before in my perennial gardens... so, I have a general rule of thumb that I try to follow... I want to be finished planting my perennials by somewhere around the 4th of July.

This is absolutely not written in stone, or any kind of rule in gardening... It's MY rule! I like to give any newly planted perennials plenty of time to settle in and grow a healthy, anchoring root system before winter sets in... there's much less chance this way that the plant won't survive.

I broke my own rule this past summer and autumn... we got in several orders of own-root roses rather late in the season. I was planting up until the end of October, beginning of November! I just hope the plants will not heave out of the ground and die. Time will tell.

My gardening partner couldn't resist the end of season sales... I wanted to be finished by September, at the very latest! But no... she could not resist buying more.

Thanks, guys, for explaining everything... these threads are gold mines of great info!