I'm sorry if this has already been covered here. I am new to this forum and I couldn't find any on this topic when I looked at recent subjects. Anyway, I am a brand new gardener this year so I have a lot of questions. One question that has been on my mind is how to best ward off leaf scorch. Since Columbus, OH just hit 100 degrees for the first time since 1999 I am getting nervous about my Japanese Maples. Some of them have no leaf scorch that I can see and some of just a bit on the very tips. But I expect that they will be having some after a week of 90 degree weather without any rain. I've read that deep waterings once a week is good for newly planted Japanese Maples and I have been doing that. I was curious if anyone else has advice for further precautionary measures that I could take. I really would love to see the fall colors of my new trees if at all possible. I'd hate for some leaf scorch to ruin the show. Oh, one last thing. I saw some youtube video of a guy talking about leaf scorch on dissectum trees. He mentioned a product called wilt stop. I was wondering if anyone has had any luck with that. It seems like it might end up costing me too much if I have to keep buying and using it over and over again, so I figured I'd ask before using it.
I have been wondering about the maples and how they will survive the summer. Here in Central Illinois we are having extended 95-100 temps with nothing much in the way of rain. I worry about even the long planted maples and leaf scorch is already happening to some. The good thing on established trees I have noticed that even if they lose some leaves, the branch looks healthy. With newly planted, just keep the roots healthy, leaf scorch is kind of secondary. I forgot about Wilt Pruf stuff, I use it in winter on all my my smaller, newer maples. You could spray it with a milder dilution, I think. Doesn't the label say that? It might be a possibility. Other than that, the deep watering with time to dry out sounds good. It all depends on the kind of soil it is planted in. If it's in heavy soil, be more cautious...watch for leaf drop, too wet. I would like to hear from some of you in the southern and western areas because I remember you had some terrible heat last year that we missed in the Midwest. Did you loose maples, or did they come back? Kay
I would recommend watering more often in what we consider to be extreme heat for our area. With intense sun and heat, not to mention the ground is very dry this year, the root area of your young maples could become dry very quickly. They like moist and cool roots. You may want to consider watering every other day. Once the tree is established and older, then you can get away with watering less often giving them a deep watering. Since the trees and soil are new to you, then you may want to check the soil moisture with your finger between watering, to get a feel for how often to water. The soil should feel light and moist, not heavy and saturated; and never all together dry. Free draining trees grown in a container can be watered daily in this heat, sometimes twice a day depending on the sun exposure.
Add some bark mulch at least three inches deep around the root ball and drip zone to keep the soil cooler. It will help retain the moisture too.
I'm struggling through the same battle right now. Weeks of 90-100 with no rain! What makes my battle even harder is I have a good bit of clay in my soil so it's a battle to keep them moist but not drowning. I'm pretty stressed. Half the time I can't tell if they are needing water or too wet. All the jms I planted this year are already showing leaf scorch so it's so hard not to water more but drowning is even worse than a little leaf burn so I've been sticking with one deep watering a week but most of my jms don't get more than 2-3 hours dirrect sun. I do have hope if I can make it through this year they will be fine and show much less leaf burn once established a little better because none of the ones I planted last year have any signs of leaf burn. It just so happens this heat wave and drought made it a very bad year for planting jms this spring. I wouldn't be too worried about the leaf burn because unless it's very bad I don't think it does too much damage to the tree but over watering can be deadly. If you don't have a nice thick layer of mulch around them, that should be your #1 priority. Other than keeping the roots moist and cool, I don't know of much else you can do. Of course you could always move them to more shade but if they are planted that's not very practical lol. Good luck and wish me the same ;-)
I agree that mulch makes all the difference this time of year. I have found using chipped pine bark works better than shredded mulch. The shredded stuff mats together this time of year, so it limits the roots ability to breathe and the water tends to run off rather than percolating down into the roots. Our solid clay underneath my mounded beds acts like a drying element since it’s been so dry. So the sun and heat dry from above and the dry cracking clay dries from below. If the soil does not drain well and the clay subsoil becomes too saturated, then a dangerous situation of dry on top and oversaturated at the root base can occur. To avoid this in extreme heat, I switch from deep watering less often, to providing adequate water every other day. I found this works since most of the fibrous roots on Japanese maples that absorb water and nutrients tends to be on the top 1/3 of the root mass.
