Trees in Containers - a Discussion

Al, I realize this is the tree/container forum, but I have a general question about the screening you recommended upthread "Use whatever passes through 1/2" screen in the 5:1:1 mix, and use what passes through 1/4" mesh but doesn't go through 1/8" in the gritty mix." I start screening, using the 1/2, 1/4 and 1/8 meshes, and try to follow some 'logical' progression and end up getting confused -- I now have bags/containers, etc. containing what will not go thru the 1/2 (the biggies); what goes thru the 1/2 (the mids), what goes thru the 1/4 (the smalls), and then what goes thru the 1/8 (the babies) -- my aim is to make both the gritty and the 5-1-1 mixes -- use the biggies elsewhere, the mids in the 5-1-1, the smalls in the gritty, but what to do with the babies? Also, you've mentioned you have sources for two different bark fines -- are you allowed to give brand names, store names, websites (if there is one)? I've only found "Landscapers Pride Soil Conditioner" which I'm fairly certain is at least partially composted, but it's the best I've found so far. It's also very wet so that's complicating the process also. I do really appreciate all the information and guidance you're providing. I really want to make my own mixes as the most prevalent market mixes around here are peat-based, mainly Miracle Grow with fertilizer already added.....
Thanks again,
Mary

I try to use a product that contains dust through 3/8 for the 5:1:1 mix, but I don't panic or feel like I need to remove the few 1/2" pieces in the bags. If I was adding additional fine screenings to bark like I just described that is going into the 5:1:1 mix, I would forgo adding all or a portion of the peat. The peat is basically used to adjust water retention, so as the % of fine particles in the bark increases, so can/should the peat fraction. Basically, a little perched water is ok in the 5:1:1 mix, but the whole point of going to the larger bark particles is to eliminate the 3-5" PWT common to soils based on peat/compost/coir.

If you have a bagging mower with a sharp blade on it, you can use it to chop up the larger pieces & screen them again ... or a friend that has a brush chipper ......

I use prescreened fir bark in 1/8-1/4" size in the gritty mix. The product I've been using for a number of years is packaged by Shasta Forest Products in Yreka, CA. I buy it on my trips to Chicago & it costs $17 for 3 cu ft, $15 when I buy 20 bags or more, which is the norm. The other products come from several different manufacturers, and it probably wouldn't do any good to list the names. You need to look for the product - sold often as PB mulch or PB soil conditioner. Look for it whenever you're in a store that swells it. I don't always get it from the same place, but I've found 5-6 places that sell fine pine bark, so I buy what looks best, often stock-piling up to a pallet at a time.

If you had a 3/8" screen, you could use what passes that but doesn't pass through 1/8". Since you only have 1/4", use what passes through that, but doesn't pass through 1/8" in the gritty mix. Mix the discards into the bark you'll use for the 5:1:1 mix, unless they're very large. Unconfused or moreconfused? ;o)

Al

The tire I have it in is about 3 1/2 feet deep so it has a long way to the Caleche. I put it there because it is close to a compost hill so the soil is probably broken down there quite a bit, under the tire after our El Nino rains this year, there is also a lot of paper under it. No seepage is evident. I do have alkaline soil in many spots but a lot of it has been amended with a lagana bed of some varying decay. The globe willow is so large if they make it, that I could only put it in a couple of spots too. I may take it out and move it, then as a last ditch effort. Thanks.

Hey, Al -- thought I had scored a big one from Oak Hill Gardens for fir bark .......... the original receipt showed 13.50 for shipping two bags, yahooo hoooo, but ... then Greg followed up with email clarification: shipping $70, grand total $104.00. Oh, well.
Mary

You should be able to get the same stuff, or a similar product at any large orchid supply places near you.

Al

Hi Al,
Thank you so much for this thread; it's just what I was looking for. We put in a beatiful patio last summer but it needs a little more shade & I'd like to use some potted trees or large shrubs while we wait for in-ground trees & shrubs to get bigger.
One question remains: what do you do with these potted trees over the winter? If the pot is flexible enough, or cheap enough to be easily replaceable, can they remain outdoors in my zone 6?
Oops, yet one more question. If we purchase potted trees or shrubs from the nursery now (nearly August,) can they remain in their pots untouched until early spring when it's time to root-prune?
Thanks again.

How you over-winter sort of depends on how hardy the tree/shrub/plant material is compared to your zone. As a rule of thumb, I usually figure plants hardy to a zone colder than mine will over-winter outdoors with a little root protection, and plants hardy to 2 zones colder are ok w/o protection, though the 'chill factor' needs to be tempered with how tolerant the plants (evergreens mainly) of drying wind/sun exposure. The north side of a building where plants are sheltered from wind would be good - an unheated garage or out-building better.

Anything that you would buy from a nursery that looks healthy, has some interior foliage, & doesn't have all the greenery in tufts at the branch ends (usually indicative of really tight roots) should be fine until spring in the container it came in.

Al

I just linked a friend to this thread & noted it hasn't seen any interest in a long while. Forgive the bump, but I think there is a lot of information here that could represent significant help to anyone growing woody material in containers.

Take care.

Al

Hi Al and everyone, I just now discover this thread. I'm pulling a chair, and ready to read and absorb the info. given.

Thank you Al for sharing your knowledge and experience with others. And most of all thank you for this wonderful insight;

Thanks, LL ..... very much! I can't remember the last time I bumped one of my own threads, but I think there is a fairly high % of growers tending woody plants in containers that don't fully understand how to keep them healthy over the long term who could benefit from reading at least the OP.

Take good care.

Most growers never grow to understand the difference between people time and plant time. Bonsai teaches you what it's like to be on plant time.

Al

I'm learning new delightful things about plants everyday. All the plants here are in containers pix was taken in mid. August.

I said "All the plants..." I should have said; most of the plants. For the weeping willows showing on the right side of the photo is a free standing tree nearby in the garden.

Hi AL!!

Im also glad to see this thread!!

Lots of wonderful things for all types of growers.. I think it needs a friendly bump!! :)

Take care,

Laura

Oh love the brugs, all my brugs and tropicals are in pots since I am zone 5. Works well for me. I am not big on rushing around and trying to dig up everything when the weather says SURPRISE we are having a hard freeze...rofl.

What is the blueish flower? That sure is pretty.

happgarden, the blue flowers belong to that of Thunbergia grandiflora. They're a tender perennial vine (hardy to zone 7b+). They usually are hardy in the garden (here) except some unusual harsh winter. So I've those growing both in the ground and in hanging baskets in order to safeguard some for the following year should there be real bad weather. Like Al has explained; trees in pots without being root pruned/ and repotted at intervals. The result is decreased vitality in the plant itself. An example; my' Dr. D/ brug. This is losing its vigor (notice the leaves are small & scarce) because I haven't repotted it in several years. Insufficient root mass and lack of nutrients.

Mine just doesn't bloom in the pot at all, it leafs out nice but no blooms since about the first two years and each year it got less. I brought it in this year early to see if it won't die back to the ground like it usually does and see if it makes a difference.

The first notable symptom of root congestion is reduced extension of branches, main stems, or vines. As the congestion gets worse, foliage tends to become concentrated nearer and nearer to apices (the growing ends of branches, from which growth (extension) actually originates). The result of that is often a poodle or pompon look. In some plants, a little stress from mild root congestion can slightly increase the number of blooms a plant produces, but stress is stress, and as such has a negative effect on the organism. How much stress (the collective) you want to subject a plant to is up to the grower, but stress unchecked quickly turns to strain, which is a much more serious condition. It's enough to know that no plant LIKES to be grown under root-bound conditions.

To optimize growth and vitality of what we grow in containers, woody plants should be potted up before the soil/root mass can be lifted from the pot intact; or, if the roots happen to be allowed to get congested - root pruning then becomes an important part of how well the plant is capable of doing from that point on. Even plants planted out after their root systems were allowed to become congested at any point prior, are sure to be permanently affected by the root issues that developed in their too small containers.

Since we can reason that plants can never grow at beyond their potential, the increase in growth rate and vitality that occurs after a potting up or a repot, what most growers consider to be a 'growth spurt', is actually only proof of how restrictive root congestion is. In the case of potting up, you reduce SOME of the limitations imposed by tight roots, so the plant can resume growing a little closer to what its potential is. Repotting, as opposed to potting up and when done correctly, eliminates ALL the limitations imposed by tight roots; thus allowing the plant to return to growing to its potential (within the limiting effects of other cultural factors).

Maintaining our plants so their roots have room to run is an extremely important part of keeping plants happy over the long term; and is why bonsai trees often live for centuries in very small pots, while many of us have trouble keeping plants happy beyond their first year or two in our care.

Al

Al, many thanks on the lesson on root-bound conditions. I've over the years learned some pointers how the environment alters ways that plants behave. Now, I'm gaining new experience with other factors such as soil, air-movement, and 'room to grow'. Some of the very basic, but so essential to plants' health.

hellnzn11. How high is the ellevation where you're? Do you get snow and hard freeze in the winter? Brugs are root hardy here, provided that we provide enough sun light which is essential for them to bloom. Too much shade in the garden (like mine) are problematic for brugs. Not only they refuse to bloom, but are susceptible to root rot over our mild and wet winter. I have noticed my neighbors' sunny sites where they have their brugs. Theirs, die back to the ground each year, but come back with re-newed vigor each spring and seldomly fail to bloom. Once they bloom there are hundreds of blooms, instead of a few scattered blooms compared to those that are being kept in pot culture. I said all that to return to the point of discussion of root-bound theory.

New questions; how and when to prune Juniper? I was told by the street- side vendor that this is a 3 year-old "Japanese Juniper" and when I asked about its temperature range for optimal growth? I was told 35F. to 105F degrees. (that's helpful so I know when to take precaution for freezing weather ect.) I am unable to differentiate between procumbens and horizontalis species. In any case, I was instructed to repot/root prune yearly in each spring. Am I lead to the right path in caring for this tiny "tree".? Thanks in advance Al.

You can prune a juniper any time. Just make sure you leave some healthy green on any branch you want to remain as part of the composition. Juniper bonsai also get pinched and thinned. Thinning is usually done with scissors and is done very selectively. Pinching is usually done as new buds are extending. Both the thinning and pinching are part of the process of forming pads or clouds of foliage. How to thin and pinch isn't something that you can describe in a forum setting - even in a book, with pictures, it's difficult to describe.

Your plant is J procumbens, and the cultivar appears to be 'Nana', which is most commonly sold as small bonsai. The primary identifying difference between J horizontalis and J procumbens is that horizontalis will have loose and floppy branches that grow close to the ground, and the plant has no recognizable crown. Procumben's branches are initially ascending, and the plant will have a dome-shaped crown as it matures, but this is only helpful for identifying plants in the landscape. For plant's in pots, the average beginner is unlikely to come across a J horizontalis being sold as bonsai starter material, and the primary difference is the loose, very flexible, floppy branches of horizontalis vs the more rigid and ascending branches of the procumbens.

Care would be the same. I would protect your plant against actual soil temps below about 28* and consider about 90* as their upper limit. If I was you, I would just bury the pot and all in the garden now & forget it until spring. It will do fine, as long as it doesn't dry out, so toss some snow on it from time to time, or water it if the ground gets dry. I repot junipers in late Apr - early May, so you could repot any time in Apr. They like a little warmth after being repotted for best root regeneration, so don't be in too big of a hurry. They want a fast-draining and well-aerated soil, like the gritty mix, and seem to really like Foliage-Pro 9-3-6 fertilizer.

Al

Wow this is a fascinating thread.

Al, I have two questions for you.

This first is I have a 30inch box Chitalpa that will be planted into the ground but the bottom of the box was missing, we didn't know when we dragged it seven feet. I know there are roots that were that low, they are some thick ones, will the tree be damaged now by the dragging, The tree was container grown, I doubt they did any root pruning though. What should I do for the tree for it to have the best chance in the ground? I also have a red oak, but its box has the bottom so its ok, Yet, I do wonder if I need to do any root pruning for it as well.

The second question is about a weeping cherry that started sprouting and then just stopped, I have a fruit bearing tree that did the same. I was reading your thread about the pruning, can I just cut the top of the weeping cherry off and let it regrow from the trunk? Can I do the same with the fruit bearing cherry?

Thank you so much.

I never put a tree in the ground unless I'm sure there are no problems in the root mass. That means I remove as much soil as I need to, in order to be sure there are no roots that are encircling/girdling, j-hooked/growing back toward the center, or growing upward. Any of those conditions are problems with the potential to limit growth, cause the death of branches on one side of the tree, or eventually kill the tree outright. Unfortunately, nurseries don't invest in the kind of care that YOU would if you were bringing a tree along for your own landscape.

At a minimum, you should top the tree on it's side and check to see if the roots are badly mangled, and remove the damaged roots with a pair of sharp bypass pruners.

Unless I misunderstood, it sounds like you might have P. x 'Snofozam' grafted to common cherry understock. By the sound of it, the graft union probably didn't take and the grafted part died. If that is true, you'll have a common upright tree growing from the understock that will look nothing like the cherry you bought.

Al

Thank you very much Al. I closely inspected my weeping cherry and I think your right on with what happened with a bad graf, it explains why half of it was never performing as well as the other half. It has since passed away. El Paso's temperatures have changed so much recently and both cherries went into shock after a few cycles of temperature dips after leafing out. Today we are in the 50's with lots of wind.

I read a lot on your thread about roots and container plants. I had to report my indoor plants, I had one plant with two roots that went round and round the bottom of the pot, just long ropes. Unbelievable. It was my fault for waiting so long. I also removed a lot of bad hardened roots that hooked and did weird things. My plants look a lot better now even though I took a bit of roots out and I did some pruning as well. So thanks again for this thread.

I'm very glad you were able to find parts you could put to use. I regularly think about how easy this stuff is to learn when you have someone to teach you or help you reason through it, but how difficult it is to put everything together when you have to do it on your own. Sharing some of the things I've learned through my efforts to become as proficient at bonsai as I'm capable of is fun for me. I suppose I enjoy nurturing people who nurture plants almost as much as I like nurturing plants - maybe even more. How lucky I am that if I ever get to the point that nurturing plants is a chore bigger than I can handle - I might still be able to nurture the growers. ;-)

Al

My winters are cold and rarely get snow at this particular house. We have heavy Caleche soil though that makes Brugs vulnerable to rot. The other Brug someone here sent me, just went hollow when it got too wet. I don't know how often they bloom. Mine just bloomed so is that it? I could look it up but I thought you could just tell me and save me the time, if you know.

My brugs and datura bloom all summer long, then spend the winter dry, in a cool basement. They get repotted (as opposed to potting up) EVERY spring into a 5:1:1 mix of pine bark fines:sphagnum peat:perlite. If you're using a water-retentive soil based on peat, compost, composted forest products, or other fine ingredients, you can get a LOT more potential from your plants if you partially bury the container ...... which turns it into a mini raised bed, from a hydrological perspective.

Al

Well I am about to have lots of Dats blooming, various stages of growth but the wild desert ones are blooming now. My Brug, is leafing out really good, so I need to fertilize every two weeks and see if I can get some more blooms out of it? Good to know that it can keep blooming?

Mine bloom all summer until I let them dry down so they can be move to a cool basement w/o roots rotting, where they stay for the winter, nearly completely dry. The roots of Datura and Brugmansia are so vigorous the plants need to be root-pruned and repotted yearly for best results (like Hibiscus). The plant blooms best when slightly root bound, but there is a big difference in the volume of blooms between slightly root bound and severely root bound (significant reduction in bloom profusion). In most cases, even if you prune roots and repot every spring, the plant will fill the pot and be at LEAST moderately root bound by the end of summer, which means that you're sacrificing blooms, growth, and vitality by neglecting annual root work.

Datura and Brugs are heavy feeders, so if you're seeing chlorosis and/or shedding of lower/inner leaves, you're probably not fertilizing enough, or you're seeing the effects of root congestion. Don't use a "bloom-booster" fertilizer. Fertilizers in a 3:1:2 NPK RATIO (NPK RATIO is different than the NPK %s. 24-8-16, 12-4-8, and 9-3-6 are all 3:1:2 ratio fertilizers) are very good choices. I'm very partial to Foliage-Pro 9-3-6 soluble fertilizers, and use it for almost everything I grow - ALL my trees except Hibiscus; but even then I still USE the 9-3-6 but modify it by adding some additional K (potassium) in the form of KCl (potash) or Dyna-Gro's Pro-TeKt 0-0-3.

Al

This has been a wonderfully exciting thread!! I've been reading for about 3 hours half way while watching a movie.
Anyway I have 2 JM's growing in the ground that are probably 10-12' tall.& 10-12 years old. Could these be dug and root pruned and top pruned into a shaped small tree in a container?? Neither is planted in a very good location. I welcome aNY ANd all input you may have for me.
~~Sheri~~

The first thing that comes to mind is, 'are these trees from seed or are they grafted to Acer understock - and if they ARE grafted, how high/low is the graft'? The pics below are from collected seedlings and are about 20-30 years old, which gives you an idea of what CAN be done, and how compact you can keep even very old trees if you have the knowledge and the will. I wouldn't expect that you would be able to produce specimens like those in the pics, but certainly maintaining a collected maple compact and attractive in a container is within reach.

The last picture is a maple forest that will be coming into its own over the next 3-5 years. All are collected seedlings about 8-10 years old

Al

How do you tell if there is an Acer understock. My JM's were purchased from a plant shop or maybe at Home Depot.

What you likely have is the result of a scion of a particular species that has been cloned for uniformity and one or more of its more desirable genetic traits, and grafted to (usually) a cold-tolerant and vigorous root system and/or stem. This is closer to the rule than the exception for most nursery stock these days. The reason it needs to be determined if that's how your plant has been pieced together is because if you cut the plant back too far, or don't prune correctly, you might end up with growth originating only from the less desirable understock. Usually, you can see the graft, which often results in a conspicuous lump or change in bark texture at the graft union.

Al

This Winter I tried to design streamlined hypertufa trays for growing or displaying my Jacaranda.

nonsai I love them, but I have a question how do you water with the soil level being above the pot? I was given a hypertufa that was planted the same way and have a terrible time watering it. Only hypertufa I have.

Growing tomatoes in containers are one of the best option for gardeners who are living in flats or apartments. Tomatoes are not the easiest way to grow but if you know how to plant them and take care of them properly, you can get fresh picked tomatoes from your home itself.
If you are looking for growing tomatoes using container gardening, try to use a big container. You need a container that is at least a square foot -2 square feet. If you are looking for a tomatoes to cook, it would be better if you can put one plant per container. Now fill up the container with a good quality soil and make sure to have good and proper drainage.
The key to success of growing tomatoes in container gardening is to give your tomato plant a consistent amount of water. The main aim of this is to keep the soil moist and not wet which means not too much water and not too little water. If you are using conventional containers and not getting too much of rain, you need to move them to a sheltered area where the plant doesn't get too much of sunlight. Another trick to maintain moisture in the soil is to water them in the morning. During this time, make sure to water the soil and not the leaves.
Feeding your tomatoes is the crucial step where almost all gardeners fail. If the plant is not given its required nutrients, it will not grow as you wish. Have some fertilizer mixed in the soil and mix it throughout your container. Its not mandatory that you need to buy any specific tomato fertilizers, you can also biy an all-purpose fertilizer.
Once you are done with the fertilizer part, the next thing you need to make sure is of the sunlight. Its OK if the tomatoes get 6-8 hrs of sunlight. If your plants aren't getting enough of sunlight, move them to a place where they get enough sunlight. But make sure that the tomatoes are not exposed to too much of heat, it can fail your growth.
When planting a tomato seedling, makes sure to cover the plant by soil removing all the leaves and branches below the soil line. With this, you get a healthy bunch of tomatoes.

I too have been growing plants in containers, and since I have a great many Rhododendrons and Azaleas I often keep them in large pots. Some in pots that are buried over their top, and some just in large pots. Either way makes it easier to move the key plants around for various effects. These acid loving plants have root balls that are matted and shallow and should not be buried too deeply. Because of that I have to water frequently in Hot Summers and Drought. I have been able to keep most rhododendrons in a pot for about 5 years, but eventually the plant becomes too root bound and must be put in the ground. The plants are dwarfed by this potting procedure, but that is what i want since a full sized rhododendron is eventually too big for its site.on my 3/4 acre plot.. I also have60-75' oaks which gives them the high shade they need. Some plants that are genetically dwarfed naturally I grow in a small raised bed sort of "Rock Garden" effect and these conifers, rhododendrons and Azaleas I keep small deliberately and when the temperatures get above 85F i turn on a "hose end sprinkler system" that will reduce the temperature by 15-20F in about 10 minutes in that area. The bed is raised to about 3' and slopes down to lawn level at the borders
I am interested in your -semi Bonsai techniques and would appreciate your comments.
DR AR Fitzburgh

Many think plants that typically exhibit shallow root masses in situ shouldn't be planted in deeper containers, but plants like Rhodies, boxwood, euonymus will happily fill even the deepest pots with a mass of fine roots if the soil is appropriately aerated. IOW, the plant isn't genetically predisposed to a shallow root system; where the roots grow is a function of cultural conditions. Roots only grow in conditions that allow them to grow. The soils are designed to hold little or no perched water, which means all the ingredients are coarse and the soil remains well-aerated with good gas exchange no matter how deep the soil column is.

You also have the option of repotting, which includes root pruning and a change of soil. When blooms fade, you would remove the bottom half of the root mass, then cut 3 wedges out of the remaining roots equal to half of what remains. So, cut off bottom half, then remove half of what's left by making 3 wedge shaped cuts, repot by filling in under the root mass and filling the voids left by the wedge removal. In the following year, you depot and remove the 3 wedges that weren't removed in the year previous. Do your pruning at repot time to help balance the top mass with the radically reduced bottom mass. This runs counter to conventional transplanting practice for plants in the landscape, but is required in cases where large root volumes are removed during a repot. They can also be repotted in the more traditional bonsai method using appropriate practices and tools, which leaves you with a fairly thin and flat root mass.

Al

Most of the plants I grow in pots are rhododendrons and Azaleas. Their roots are fibrous and while in nature they are usually mountainous plants. I have been incorporating small 1/4 " to !/2 stone pebbels in my planting mix. I have found that while most grow well in that sort of mix, there are some plants just do not do well in containers even though the mix and the same areas are the same. It has always amazed me that in nature a 10 ' rhododendron can grow out of a rock base crevasse. Some how the roots must find sources of food and water inside the rock.
When I buy a new rhododendron the first thing I do is to take it out of the pot and smash the root ball against the ground again and again until most of the dirt surrounding the roots is gone. I then cut any circling roots and long girdling roots off and repot he plant in a shallow but wide dish, using the dirt I took away from the previously root bound potted plant and mix it with finely ground pine bark and small pebbles and peat moss and tease the mixture into and between the the remaining root ball until the plant is firmly seated in the mix. I usually support the upright stem and plant with a stiff post or cage of pig wire mesh. The container must have several 1/4 to 1/2" holes all over the bottom. The roots of such plants need oxygen and perfect drainage to be able to have the water flow around them and drain Quickly pass out of the container. I keep the plants hydrated as I told you earlier by placing them where a a mist will cover the leaves. With this method I have been able to grow plants that ordinarily will not survive Hot Summer Temps. this is a good method to grow what are ordinally difficult to grow.
In some other plants this does not work well. Especially if they if they are plants that in nature usually grow in damper areas and for me at east , seem unfit for such pot culture, There comes a time however that the plants have grown too tall and are unbalanced in a pot that is too small for spreading roots. I then have to remove the plant from its shallow pot and plant it in the surrounding ground still using the same principles of sharp drainage and top of the ground planting because it would probably keep the plants dwarfed and allow me to grow more plants in a given area.

I grow in containers, but I try to Air Prune to keep the roots healthy. How does your advice change for people growing trees/shrubs in large grow bags, or in pots with large holes and landscape fabric, to air prune the roots? This picture is an Almond, planted this year from bare root, with a reservoir. 4" circular holes with fabric. Thanks.

I just wandered over to this thread.................the part about the container tomatoes was interesting.........I have 2 questions.............can I grow the toms in containers in my greenhouse? Obviously I'd have to start some from seed since there aren't too many places here that would have some for sale in this 0 degree weather. LOLOL

And #2..........I didn't think I could grown a rhodie in a container...........thought they had to be in the ground??? Might be something for me to think about when those lovely ones are out for sale in 2 or 3 months.