Problems with Conifers in Summer

[ECMist]

This is my first summer doing bonsai, and most of my deciduous species are doing just fine. However, three of my conifers don’t seem to be doing so hot. My rocky mountain pines are 5 months old seedlings but are dropping their needles (but only old ones near the bottom), and I’m wondering if this is because of the heat/sun or just because the needles are older. My Juniper doesn’t seem to be doing too well either, not sure if it’s because of the heat/sun, because of the fact that I had no idea what I was doing when I pruned it (perhaps too much), or a combination of the two. The only other conifer having problems is my Bald Cypress, which is developing multiple brown spots on its foliage. For a while I didn’t see anything and ignored it, but recently I have found little snails on it, which I find really strange as I have never heard of such a thing. I’m wondering what the causes for these issues might be, as I’m quite puzzled how to save these conifers. They are all on a south-facing bench with a 30% shade cloth over them, recent weather has been around 95-100 degrees here. Please let me know if anyone has any ideas how to help these little guys!

 

[WNC Bonsai]

The bald cypress may have mites but more likely is just due to sun burn. This is pretty common on BC. The pones are problably just dropping the old needles. The juniper seems to have lots of new growth on it but the foliage is very sparse, did you do a lot of pruning on it this past winter/spring? It has a lot of juvenile growth which happens when they are over pruned.

 

[Paradox]

Pines and juniper seem like older needles dropping off which is normal
Bald cypress almost looks like sun burn to me but not sure

 

[RJG2]

Do you have pictures of the "snails"? It could be scale insects (a pest).

 

[ECMist]

I did prune the juniper this spring after I bought it, it almost looked as though it had never been pruned before. I don’t have a whole lot of knowledge on junipers so if you say it looks fine then I won’t worry about it. I don’t think they were scale, as the snails left slimy trails on the tree afterwards, but I unfortunately didn’t think to take a picture when I plucked them off. How would you recommend I deal with the sunburn? I can’t really move it elsewhere…

 

[WNC Bonsai]

You can either ignore it and just let the needles drop when they get ready or you can strip them. To do that just pinch the base of the branch and then drag your fingers towards the tip pulling off the leaflets as you go. On trees with strong growth you can defoliate the whole tree mid-summer and that can create a new flush of growth on the tree. Probably not something a newbie to BC should try though.

 

[ECMist]

You sure they don’t sell sunblock for trees?

 

[BrightsideB]

The best you can get is shade cloth

 

[ECMist]

Hmmm… perhaps I’ll have to get another one then.

 

[Paradox]

Not sure too much sun is your problem since you already have them under a 30% cloth.

When it gets above 90 or so, I'll sometimes water twice a day. Their regular watering in the morning and I'll do second watering after work.

As I said in my earlier post, the juniper and pines are losing old needles which is normal.
Both look like they have healthy new growth otherwise.

Pines and juniper are full sun all day trees. The heat without enough water can be a problem for any tree.

 

[ECMist]

I’ll start watering twice a day to see if that resolves the issue. Thanks a lot!

 

[Paradox]

I’ll start watering twice a day to see if that resolves the issue. Thanks a lot!

If you think they need it.
Ie: the soil is dry

 

[Paradox]

I’ll start watering twice a day to see if that resolves the issue. Thanks a lot!

Put a wooden chopstick in the pot and leave it there. Check it once or twice a day and look at it and water when its almost dry.
A wooden chopstick is a great way to monitor soil moisture and learn when to water

 

[ECMist]

Usually I water in the afternoon and every time the soil appears dry. I went out this morning after watering yesterday afternoon and it was dry. I’ll water again if it’s dry this evening, which is more than likely.

 

[Paradox]

Usually I water in the afternoon and every time the soil appears dry. I went out this morning after watering yesterday afternoon and it was dry. I’ll water again if it’s dry this evening, which is more than likely.

It's very important to water when the trees need it, not on a set schedule per se. My watering frequency changes throughout the season. Every other day in the early spring and fall when it's cooler and we get more rain. Every day late spring and summer unless it's really hot then I'll water 2x a day. I learned this cadence by checking my trees daily and learning their water needs.