What is the Best Location

[RobGA]

I have this Juniper with sharp juvenile leaves. I purchased this 5 years ago and it has been sitting in the original nursery pot. Last year I moved it to a pot I had and thought it might make a nice cascade. I also did a bit of trimming. I kept it on my deck until recently. The deck gets eastern sun but I have a lot of trees that shade the deck. I moved it to my front steps a few days ago as that faces west and gets blasted once the sun goes over my roof. I read that Juniper growth is enhanced with the more sun they get and on my back deck it wasn’t putting out a lot of growth. I haven’t touched it this year and the growth seems so so and branches are leggy.

Is putting it in a west facing location a good idea? When should I cut it back to produce more compact growth? Should I cut or bury the roots around the base? I don’t know what type of juniper this is and am hoping it gets the softer mature leaves.

 

[Colorado]

I think that is some kind of procumbens juniper. However, there are several juniper species and cultivars that have this type of foliage.

If you want the soft foliage, you should get a shimpaku type of juniper. Kishu, itoigawa, etc.

 

[Bonsai Nut]

You are asking two separate questions, so I will answer them separately.

How much sun do junipers like? As much as you can give them. The more sun they receive, the more compact their growth will be. They tend to take a while to recover after their roots are disturbed, so you might want to provide some sun protection for a few months after a repot. But once established, they love full sun, all day long.

Will my juniper ever switch to soft "scale" foliage from its current prickly "needle" foliage? It depends entirely on the type of juniper. Some are 100% needle, 100% of the time. Some are 100% scale - and you have to work to try to see needle foliage. And some are in-between, where they will have scale foliage if you leave them alone and allow the foliage to mature, but if you prune them too hard they will respond with new growth that is needle. Not a lot of help, I know, other than to say that scale foliage is not automatic.

 

[RobGA]

What do you think about trimming the thin surface roots this fall, or burying more deeply? I am hoping more sun will get it to back bud and be fuller and less leggy on the cascading branches. Also half of the container is blocked so the roots can only grow in the top half.

 

[Shibui]

Is putting it in a west facing location a good idea?

Lots of sun is good for most bonsai provided you can water appropriately. Junipers like sun but they definitely do not like to get totally dry roots. As has been mentioned, all trees develop more compact shoots and smaller leaves when they have more sun. less sun gives longer shoots and larger leaves.

When should I cut it back to produce more compact growth?

Whenever it needs it. I have not noted a time of year that is not good for trimming junipers. Caveats are: don't take huge amounts off at one time and allow the tree some recovery time before hitting it again; and allow time for recovery after repotting before pruning more than a little off junipers.
Some junipers have naturally open growth and nothing you do will make it compact and dense. I'm pretty sure you can do a bit better with this type but it still will never be as dense as a Chinese juniper.

Should I cut or bury the roots around the base?

That depends what else is there. Junipers naturally grow extra roots if the trunk is buried a bit deeper. Some of mine even grow aerial roots from the trunk above ground level if the foliage is dense and soil damp enough. I suspect that's what has happened to this tree while it was in the grow beds wherever it was grown.
There is usually much stronger, older roots just below in which case just cut the upper ones but if you explore and find just 1 large root underneath I would keep the new roots and cover them so they thicken and become the new surface roots.

and am hoping it gets the softer mature leaves.

I suspect you are in for disappointment. Looks like J. procumbens to me and procumbens rarely develops the softer scale foliage.

I am hoping more sun will get it to back bud and be fuller and less leggy on the cascading branches.

Extra sun should help address the open areas but you will need more than just sun to address the bare areas on the cascade. Despite being a prostrate type juniper these are still apically dominant which means the upper parts will always grow better than lower parts. Whenever the top part is allowed to dominate the lower parts will slowly decline. YOU need to balance energy distribution by trimming and thinning much more in the upper sections to convince that tree to invest a few more resources into the lower areas.
That's just one of the facts of life for cascade plantings.
Extra fertiliser may also help this one grow better.
I would also be allowing the tree roots access to the full pot rather than restricting root run. I think you'll get much better results that way.

 

[RobGA]

@Shibui Wow, thank you for the excellent responses to my queries. I will cut back the upper part a bit to hopefully allow the lower parts to get more resources. I was hoping the needles were still juvenile as I am not a big fan of the needles. I have seen junipers with both types on the same plant and understood that if you do a large trim you run the risk of losing the scale leaves and getting more needle. This juniper hasn’t ever shown any scale leaves. I also read that if you just cut away and don’t carefully cut the needles completely from the branch, you get a lot of brown needles.

 

[Bonsai Forest]

Since the tree wants to be an upright and has grown as such for so long as one, it might be best to keep it that style. Cascade does not suit this particular tree and the cascading trunks are too long, leggy, skinny and bare. The main part of the tree would benefit having the downward branches removed so it can focus resources up top.

Almost any new garden center or nursery juniper Procumbens ground cover would make Cascade light years ahead of and better than this one. All you have to do is prune away the branches that will not be the main Cascade trunk, tilt the container over to imagine the new position in a future repot and you’ll be far far ahead of where you are now.

 

[Bonsai Forest]

As an example:

Any nursery material like this


Can become this


from March to June in one season

Less than $40 and in 3-4 months you’ll have a dense and compact cascade to work with on ramification of side shoots and their pad development. Keep only the longest, thickest, and most interesting trunk line with decent side shoots/primaries growing off of it.

 

[Shibui]

I have seen junipers with both types on the same plant and understood that if you do a large trim you run the risk of losing the scale leaves and getting more needle.

This is the reality on junipers that have scale foliage. J. procumbens rarely develops scale foliage so pruning won't make any difference.

I also read that if you just cut away and don’t carefully cut the needles completely from the branch, you get a lot of brown needles.

This could be several things. I suspect the second:
All needles get old and die. Working life of juniper needle is 2-4 years. After that they turn brown and die but new ones have grown further out on the branch. For us this means that inner parts gradually turn brown and bare unless we modify growth to promote more new, inner shoots. Targeted pruning is the key. Stop long outer shoots and thin other growth to encourage more inner shoots to develop then gradually replace overly long branches/shoots with the younger, inner shoots.

Trimming can also cause browning needles. If we cut through a needle the remaining base will likely turn brown then, usually, fall off. This can give a (temporary) brown tips after careless trimming with scissors. Note that does not harm the tree, just looks unsightly for a few weeks. I often scissor trim junipers in development because speed is more important than aesthetics at that stage. to avoid browning after trim just take care to snip between needles if possible.