No stem or branch growth every year

Discussion in 'Maples' started by cthenn, Mar 7, 2017.

  1. cthenn

    cthenn Active Member

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    Bay Area
    Hello, I am wondering if someone can help me figure out why many of my maples (in containers) do not seem to be growing. Every year, the plants will put out leafage, some years better than others, but there is hardly any growth, or branching at all. I've attached a picture which demonstrates this. You can see some good stem and branch growth from years prior, but then in the past 3 or 4 years, not much has happened. What I end up with is very short, stubby shoots from each year's "growth".

    As background, usually every year I will pull the plants out of the pots, check the roots, and move them around a bit in their soil. If it looks like they need a bigger pot, I will transplant. The only thing I don't really do is fertilize very much. Maybe some fish emulsion once in a while, but usually just water. Perhaps in a container, I need to be more proactive in fertilization. If the belief is that is the problem, which fertilizer is good for container maples?

    EDIT; I see there is an entire thread on container fertilization, so that part of my question can be skipped, thanks.

    Thanks for any advice!

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  2. AlainK

    AlainK Renowned Contributor Forums Moderator Maple Society 10 Years

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    nr Orléans, France (E.U.)
    Firstly, I'd ask "What maples?..." Some species, or cultivars have very short internodes, so whether you grow them in your garden or in a pot, there won't be much difference.

    Secondly, what kind of soil mix are you using?
    0soyoung likes this.
  3. Jaybee63

    Jaybee63 Rising Contributor Maple Society 10 Years

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    Fareham, Hampshire. Hi UK
    I was in the same situation last year, hence the post.
    I ended up using Osmocote 6 month tablets Osmocote® Controlled Release Plant Food Tablets | Love The Garden
    Fertilised with the tablets early spring as coming into growth. Used on the low dose recommendation and pleased with the results. Good natural growth with a lot more leaf on plants that had become stagnant with growth, despite repotting and root pruning every 3 years.
    No leggy growth either, so pleased with the results and will be using again.
  4. JT1

    JT1 Contributor

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    Euclid, OH USA
    This can happen for a variety of reasons.
    -The first is lighting. If the tree is grown in a container and is getting too much sun or too much shade it will leaf out then do no growing at all. Since your maples were growing for years before, but have slowed and come to a stop over time, if the lighting is the same then we can move on.

    -The pot is getting too hot. Roots that bake in the summer sun will cause root damage and result in no growth. Consider using a insulated pot, or a pot color that does not attract so much heat, or move the pot to a location that it gets more shade but still allows enough sun to hit the canopy. Sometimes just putting complimentary pots around the tree pot filled with accent plants will shade and cool the maple root zone while creating an eye catching combination of plants and containers that add interest to your garden.

    -Next is mulch. I have seen container grown maples put on growth and then slow or stop as the roots fill out into the surface soil and now they are getting too hot. Consider applying pine bark mulch that is 1" square with some smaller chips mixed in to help keep the surface roots cool.

    -Check for disease. If you have black areas or spots on the trunk, this limits moisture and energy transfer in the vascular system of the tree reducing its efficiency and will slow down or stop seasonal growth.

    -Soil mix.
    If your soil mix is too wet it will limit oxygen to the roots and cause a tree to not grow.
    Soil mix that has become too compacted. If the surface soil is compacted it is limiting moisture and oxygen exposure to the entire root mass. The center is starved of oxygen and moisture while only the pot walls are getting moisture.

    -Nutrients have leached out of the soil mix over time. The center of the root-mass is starving and the freshly added soil at the outer part of the pot during re-potting is not enough to sustain healthy growth.

    -Water supply-If you have city water with chlorine, seasonal watering with chlorinated water can cause a buildup of chlorine in the soil over time. Consider using filtered water or even better, rain water for your container grown plants.

    I recommend you consider vertical mulching. Vertical mulching will fix problems with oxygen, moisture, and nutrients. It will restore balance to your container soil.

    Vertical mulching creates vertical shafts in the root mass to ensure oxygen, moisture, and nutrients can evenly penetrate into the root mass that is lacking due to compaction or a soil mix that is too moist. Which both limits oxygen which is needed in order for the roots to take up moisture and nutrients.

    What is needed to make a vertical mulch mix, components and tools.
    My mix consist of 3 components. Organic material, aggregate, and fertilizer. Must be free of silt or fine dust. All Need to be about the size of coarse coffee grounds, not fine espresso ground as that is too silty or dusty and will block oxygen and moisture; if the components are too big it will allow too much oxygen into the roots or may even block the mix from properly filling the shaft.

    I use the following.

    -PHC ROOTS 7-7-7 fertilizer. All organic, slow release with added beneficial bacteria and microbes that improve the health of your pot mix and your tree. This is hands down the ONLY fertilizer that I will use on maples. I have been using for 4 years after a 10 year hands on research project on fertilizers. This fertilizer is available from AM Leonard.
    A.M. Leonard Tools for the Horticultural Industry since 1885.

    -Sharp silica sand or similar aggregate. Again its important that its the size of coarse ground coffee and not too fine like play sand or too large like pea gravel.

    -Pine fines, also sold as soil conditioner. This is free of any silt, soil, and peat. The pine fines act as organic matter that helps retain moisture, without staying too wet or drying too quickly. It helps provide a healthy balance of moisture and oxygen.

    -A 6" L x .3 to .5" W pointed spike or medium to large Phillips-head screwdriver of similar size.

    -Mixing bucket

    mix 1/3 pine fines to 2/3 sharp silica or aggregate. Use 1/3 to half the recommended PHC roots fertilizer amount for your tree or container size. Add this to your mix, but be sure that the amount is no more than 1/3 of your mulching mix (fertilizer is no more than 1/3 of the total pine fines and silica sand mix) Mix everything together in your mixing bucket and when you take a scoop as a sample you should see an even consistency of Silica sand, pine fines with a lesser amount of fertilizer present to ensure it is well mixed.

    Measure the length from the trunk of your tree to the inside pot wall and divide by 3. For example lets say the inner pot wall to the trunk is 6". Divide by 3 and you get 2". Grab your spike and position it 2" from the pot wall and in the 12 o'clock position. Push the spike into the soil gently and rocking it back and forth gingerly to avoid damaging roots. make a hole that is 1/2 the depth of the pot. We do not want to go all the way to the bottom. It should be atleast 3" deep but not more than half way the totla depth of the pot. Most pots will allow you to go 4" to 5" inches deep and that is deep enough as most feeder roots occur in the first 3"-4" of surface soil. Rock the spoke in a circular motion so that it make a hole that is between the size of a nickle or quarter. Pull the spike out. Fill the hole with your vertical mulching mix about half way. Use spike to gently tap the mix in, then fill to the top of the hole and create a slight mound at the surface no more than an inch above the surface soil.
    Move your spike to the 3 o'clock, 6 o'clock, and 9 o'clock positions and repeat. Keep in mind that the hole should not hit the pot wall. If pot tapers inward, do your hole at an angle inward so that it does not hit the pot wall. We want water penetrating the soil mass and not escaping down the pot wall. Water the pot and if the mix settles, add more mix and water again. If soil is severely compacted you can use a thinner spike to gently aerate the surface area of the root mass penetrating 2" down but don't widen the hole like you do when making the hole for vertical mulching. The following year these steps can be repeated in the 1:30, 4:30, 7:30 and 10:30 positions or in-between the vertical mulching holes made from the season before. Or for very large pots you may want to vertical mulch in all the positions mentioned above.

    Additional fertilizer and mulch can be added to the root surface just as long as the cumulative fertilizer application does not exceed 1/2 the recommended dose.

    Please note that vertical mulching as described above is not just limited to container grown trees. The technique can be used for landscape grown trees too. It will improve the overall health of the tree increasing vigor and promote back budding and fullness in the canopy.
    Last edited: Apr 26, 2017
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  5. 0soyoung

    0soyoung Rising Contributor

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    Anacortes, WA
    I suggest getting a meat thermometer probe ($15 or so at your grocery store) and sticking it in among the roots to see just how hot they are rather than guessing and waiting. Roots should be kept below 95F (35C).
    emery and AlainK like this.

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