Magnolia, Persimmon and Crepe Myrtle Growing Perhaps Too Fast

 

A. Thank you for the great pictures and breaking them into
two emails. That helped quite a bit. Here are some comments on what I saw.

First general comments. The plants are actually doing
quite well, maybe even a bit too well. There is plenty of new growth which is
what you want but because they are so “happy” they are growing very quickly and
thus you are getting big spaces between leaves and buds. This results in an
“open” appearance.

Many of your plants, now that they are getting lots of
nutrients, water and in a great growing condition are now growing as fast as
they can. This will result in larger plants that will start to flower or fruit
further and further from the ground as they get closer to their mature size.
Plants do this naturally because in nature they are always competing for
sunlight and other resources that keep them alive.

How do slow them down? We focus on two things: reduce
those “goodies” they are getting that encourage a lot of growth (water,
fertilizer) and (this next part is harder to realize a bit) get the plant to
reduce its own growth in each of its growing branches by increasing the total
number of branches it has to support. This then causes the “goodies” that
encourages growth to be divided up among many more growing points and slows it
down. It’s like having an income of $50,000 a year and having to support three
children or 20 children; your resources are divided up many more times  so each “child” gets less.

Generally speaking, reduce “goodies” by reducing your
watering frequency (how many times you water per week if possible but not by too much) and cut your
fertilizer application in half (but not to the point where it is starving or
gets leaf scorch) and (increase the number of growing points or “children”) prune. The type of pruning you
will mostly do this winter will be what I call “heading cuts” rather “thinning
cuts”. Heading cuts increase the total number of shoots in a tree while
thinning cuts typically do not. If you want to see the difference, please visit
my Youtube video on this subject

http://www.youtube.com/watch?v=yKDSzCfvqe0

Now your individual trees, you must decide what you want
for the ultimate height on these trees. If you want them to be large (such as
flowering trees for beauty, shade or screening) then let them go and don’t do
much pruning.



Crape myrtle showing some impressive growth

If you want trees to be smaller and more compact (fruiting and
harvest for instance) then you will cut them back pretty hard and take away
from them their luxurious growth. You will prune these trees twice each year;
once in the winter and again (taking away new fast luxurious growth) in April
(summer pruning).

Crape myrtle. I would assume you want a larger tree,
perhaps with multiple trunks (3 to 5) coming from the ground. Don’t reduce the
height. Let it go. Pruning will focus on removing dead, twiggy growth (it has
lots of these due to flowering) and use thinning cuts to eliminate branches
growing too close together, one branch growing on top of another, branches
crossing each other, etc.).

You can reduce the height by making thinning cuts
and removing the tallest limbs and branches back to a “crotch”. I would not do
much of this until it gets closer to the height you want it to get. You will
fertilize in January with an all-purpose soil applied fertilizer such as
16-16-16 or even a rose fertilizer. You will see benefits from adding iron
chelate to the soil in January and foliar applied fertilizers such as Miracle
Gro about two or three weeks after the leaves emerge in the spring.



Magnolia open growth with sparse leaves

Magnolia. This is another tree you could elect to let it
grow. Having a multiple trunked tree will help
to keep it smaller. You realize
that this tree is not a terribly good choice for our climate so you will spend
more effort and money on this tree than many others. It will need the mulch
which you are doing. This will give it some soil improvement near the soil
surface as it decomposes.

It will require a fertilizer application in January
to push new, healthy growth. It will also benefit from an iron chelate. It will
not most likely need a foliar fertilizer but it will not hurt it if you chose
to apply it in February or March. Your choice but it might do better if it is
kept smaller than the mature height it will try to reach. Perhaps if you can
keep it in the 25 to 30 ft. range it will be easier to keep healthy.

Perhaps
saucer or star magnolia might work better in the future. Not as pretty but
still pretty. There is a southern magnolia called Little Gem that is smaller.

 



Persimmon growing perhaps a bit too erect and fast for its own good

Persimmon. Cut this tree back hard if you want your fruit
closer to the ground. Your tree is too lanky. Cut back into older wood about
half way in where it is too long in late January or early February. Don’t be
afraid to do this. It will handle the hard cuts. Fruit is produced on current
season wood so it will flower and fruit from new growth.

I hope this helps.