Trees in containers

In another thread, David mentioned that keeping the trees in containers can be a real pain. I am hoping he and/or others will elaborate. I have several small (some would say tiny) JMs in containers for the time being and one that I intend to keep in a container on my patio (Viridis) long term. I am using a tree/shrub potting soil with foam peanuts in the bottom of the container for drainage. I am getting ready to pot up one more, my Acer Shirasawanum 'Full Moon' for at least a year or two as it is now planned for a spot in the back yard where a deck is going in first and we aren't ready to do that part of the hardscape yet...have other things to do first. I have a couple of choices. I can go ahead and pot it up until the deck and its future spot are ready (near the deck). Or I could put it in an alternate location for the interim time and then move it later. Is there a recommended type of soil I SHOULD be doing? I chose Miracle Grow tree and shrub mix, but it isn't too late to make some changes with my trees. My pots have drainage holes in the bottom and are on casters to facilitate moving them around the patio for sweeping. The Shirasawanum is the largest tree I have at the moment.

Laura

largosmom, I have 4 JMs in pots as we speak. One, my Dancing Peacock, I have had in a pot now for around 5 or 6 years. It is a good size. Two, a Butterfly and a Geisha, are both small but nicely branched. The fourth is a Full Moon Aureum that is scheduled to go into the ground after I have determined where it is most happy.

During the winter, we take our tree pots, put them into the basement of an outbuilding we have and water them once. That's it. When spring hits, we take them outside, gradually acclimating them to light and weather. We have had no problems. I have read that JM roots prefer to be a bit tight in the container. We have only transplanted the Dancing Peacock once in 5-6 years. It is very happy. The main thing we do is ensure that there is VERY GOOD drainage! We NEVER let the pot sit in water.

Here is some more info:

http://www.komotv.com/features/gardenguys/tip_101.asp

"Japanese maples adapt well to life in a pot if the compost is kept evenly moist (not wet). Prepare the planting soil with compost, which allows good drainage and aeration with a high percentage of organic matter such as Whitney Farms Planting Compost. Feed containerized maples in the spring and early summer. Re-pot every couple of years if necessary. In winter protect the roots by covering the pot with bubble wrap and raise the pot from the ground to aid drainage. Avoid placing pots in full sun."

Largosmom - I would put the Full Moon in a pot until you are ready instead of in the ground. It'll be less stressful on the plant come transfer time.

As for the soil, I would not recommend Miracle-gro soil (or any MG product for that matter). The tree and shrub mix might be alittle heavy for maples and it contains manure which will potential give you burnt leaf tips. Plus it has the dreaded "continuous release fertilizer" that "grows big beautiful shrubs". Not exactly what you want if you're concerned about keeping them in containers, not to mention what the constant feeding does for plant cell structure. And that particular mix even mentions on their bag "not for containers".

Try to find a simple mix like the Master Nursery Planting Mix http://www.masternursery.com/. It is light mixture that's not real rich and drains well.

Yes, I forgot to mention that my DH makes our own potting soil every year. I don't know his recipe, but it is good stuff. Plus that, he can vary the ingredients based on what plant we're potting. Good advice from nurserydude.

There has been a rather indeath ;>) discussion on this at the garden web ...as soon as I find I'll post the link ...but be prepared for alot of do it yourself stuff ...In a nutshell a soiless mixture is best and those guys don't even like peat based stuff although i think it is ok . From what I have learned most important is drainage and compaction of the mixture which can be helped by pine bark and varias other more bizzare stuff like crushed stone of some sort...and fertilize in the spring only and they also hate TR fertilizer and prefer a low dose low nitrogen mix like a rose fertilizer...As i said I have asked their expert to send me the link then I'll post it here remeber with this sort of mix you need to water OFTEN but obviously not excessively . I am trying a mixture of Promix ( peat based but GOOD stuff ...not cheap but a bale goes a long way if mixed) and composted and fine chopped pine bark..David

Thanks so much, I will look for that mix. I can use the MG in my flower beds easily. My clay soil can use all the help it gets. I use styro peanuts in the bottom of the pots to provide plenty of drainage and to lighten the weight load. Most of my pots are not too tall, so I may have to get some perlite for the new soil. There are two nurseries listed inside of 10 miles on the site link you provided, so I will see if they have the mix there or can get it for me.

Will I need to amend the mix at all?

The Shirasawanum is still in it's nursery pot, but I have one almost the same size waiting for it. The others are still babies about 2' tall, so it is easy to change their soil out at this point, and it is rainy season here, so transplant shock should be minimal...I'll be very gentle on them.

Laura

Here is my mix and I use it for all my plants, be it conifer or deciduous. (1) 4 cubic ft. bale pro-mix BX, (4) 30 quart bags high quality topsoil (I prefer Fafard) 2 cubic feet super coarse perlite, and 2 cubic feet coarse vermiculite. I do not fertilize on the first year. I found out that this is the best mix and of course everything is sterilized from the bags.

Using a bark mix in my area does not seem to be the best mix. I believe that the winter dry freezes the roots because the fast drainage of water. The mix does not stay moist very long.

If growing in a container, you can either plunge the pot in the ground, then lift it every 3 rd year to root prune, or in the fall you could gather the fallen leaves and mulch around the pots to insure the winter insulation. This method will at least insure that the plants will be watered by nature.

You can also make what we call a cold frame or cold house (no heat). Plants will survive well if covered with plastic or windows.

Dave

Ok you asked for it ...these folks are serious into the minutia ( sp) of soil but have alot of good ideas I think Daves mix would do just fine although it would probably give these guys a heart attack ;>) David

http://forums.gardenweb.com/forums/load/maple/msg112314383375.html?23

Hmmm, will have to do some shopping around this week and see what I can find that is appropriate in my area.

Laura

DAVE>>> you said : " Using a bark mix in my area does not seem to be the best mix. I believe that the winter dry freezes the roots because the fast drainage of water. The mix does not stay moist very long."

This i would agree with ...pretty much any soiless mixture needs constant watering which for moist of us would be no problem but I'd expect for a nusery it would be a big one unless you have a misting system which could prove counter productive for jm's since they donm't like toi be too wet. I can't belive how dry a soiless mix 3 gal port with even an average sized tree gets ...in the summer you got to water every two days at LEAST. But I think that using this mixture instaed of an organic one is suppose to keep bacterial fungus and other JM'killers OUT...which answers this at the beginning of your container "experience" but you still have a breeding ground for this "bad stuff"!!! ...and that leads to my next question

One question though in your post you talk about sterlizing out of the bag ...how do YOU do this or are you talking about buying pre sterlized medium ????>
David

"moist of us ... should read " MOST OF US "...undoubtably a rainium ( wet freudian) slip ;>0 HA !!

That is correct. Everything in the bags comes sterilized. I have shade cloth over the houses giving 30% shade and water every 3 days about 1 hour. The maples are mixed in with other evergreen and deciduous plants and no problems. The mix I make allows for quick drainage, but also retains the moisture.

Dave