Hi all. I'm brand-new to the forum and to gardening in general. Please help me diagnose the problem with my Japanese maple, orange dream. Background: Tree is from a local nursery in Richmond, BC and was planted into a container last summer. It is in potting mix within a cuboid container whose dimensions are at least 2-fold that of the original root ball. It did well its first summer/fall and I think it wintered well. The container is placed within a covered patio facing east, modest wind exposure, and abundant morning sun, generally sheltered from sun for the rest of the day. Problem: This spring, as it was beginning to leaf out, the leaves have not appeared particularly healthy, ultimately browning from the tips, becoming wilting, then brittle/dry, and eventually falling off. I've attached some pictures depicting this in its various stages, as well as healthier looking leaves. I'm worried I've been overwatering it. Conversely, I also wonder if perhaps I'm underwatering it. This spring, my usual practice is to water it deeply (perhaps 4-6 litres) every 7-10 days. Between waterings, the soil does not appear particularly dry. I've not applied fertilizer. Any advice would be greatly appreciated!
Good morning @jlrichmond and welcome to the maples forum. Firstly, Orange Dream is a very sensitive cultivar and will react very quickly to differing environmental conditions, that being said, yours appears to be well protected. So the next thing to consider is what soil you have planted your tree in. Maples need a very free draining soil and if they sit in too much water that does not drain away, then you will get the problems you are seeing. Often people see brown tips and give more and more water. But this is not the best thing to do. Can I ask how many drain holes you have in the bottom of your pot ? Just an example, for the pot you are describing, I would have at least 4 drain holes in the bottom . Otherwise the roots cannot breathe and are liable to root rot. So the first thing to do is check drainage IMO. If you can create more then do so. As far as those leaves is concerned, they will brown and drop early. But if you remedie the drainage problem, then the second flush of leaves will look a lot better. Regarding soil mix, I use a good quality compost, peat, horticultural potting grit, horticultural pine bark and depending on how much rain you get there in Richmond, add some perlite for extra aeriation. Hope that points you in the right direction. But remember Orange Dream is very sensitive to too much sun as well.
Hi, @Acerholic. Thank you for weighing in. The container has but one drain hole, about 2 inches diameter and in the centre. I had lay in a thin layer of landscaping fabric at the bottom of the container before putting in potting mix. I wonder if that's also impeding drainage. If indeed drainage is the problem, I'm wondering if it's too late to replant it in the container. I would drill some more drain holes and add some better-draining substrate to the soil as you suggest. Of side note, it is not exposed to much rain between waterings, as it's pretty well covered by the balcony overhang. Thanks for your insight!
I hate landscaping fabric tbh. It really does not allow good drainage. Its the same if placed around maples to stop weeds, it just does not allow for good airflow to the roots. Ideal for paths only IMO. I would definatly remove it when you can. Re timing of a transplant, you can slip pot it now into some good free draining soil. Slip potting basically means you are not disturbing the roots and placing your maple in good soil as a temporary fix. This is often done when you purchase a maple during non repotting times, but want to give it some fresh soil and it appears pot bound. I carry out all my repotting in late March, just before bud break and it is still dormant. It seems by what you say that it has not been getting too much rain, but when you do water,, IMO it is not draining. You said in your first posting that after 7 -10 days it still does not appear that dry. It should do if it was draining properly. So to re cap, it's in a good non windy sheltered position, with early sun and afternoon shade. That's exactly the correct placement for a maple. So after reading your second post I am more confident that it is a drainage issue, especially with the drainage hole covered with landscape fabric. So do remove that fabric ASAP, even if you do nothing else this season.
Hi Derek, Thanks so much for your insights. I will slip pot it immediately with more drainage holes in the container and get rid of the landscaping fabric! Will provide an update down the road. Thanks!
Hello - I may have missed this in the posts above so apologies if I have..but I can’t recall seeing any references to crocks in the bottom of the container/pot, only landscaping fabric..it’s critical to add several inches of broken pots in the bottom of the container..I spend some time and effort placing them such that the holes in the pot are not obscured and there are several layers of void space and the terracotta pieces.. I probably go over the top with 3-6” deep of drainage crocks.(pot size dependent) .however 3years later you can put your finger in the holes underneath and there’s no sign of potting compost/medium - just dry crocks!
Well, let's start with where we agree: too wet, landscape fabric bunging the drainage hole, will probably be OK eventually. This is one of those situations where @dicky5ash grows amazing looking healthy maples in pots, so it's hard not to feel like a dope disagreeing. Unless what you're saying Rich is that the crocks stop the exit of soil out the hole in the pot; that's certain, but they also inhibit drainage. The science on this is like 150 years old, and there are so many authoritative references available discussing why it's a bad idea, that I will leave the googling to you (unless you really force me to do it, lol). The issue, in large, is that the crocks raise the water table in the pot, so that the roots are wetter. The is true for any change of texture of substrate medium throughout the pot. A search for "perched water table" should find appropriate discussions, and I also believe Linda Chalker-Scott has an article about this on her "debunking myths" page. In terms of when to pot, I do it now, after the first flush, with good success. But I don't like to repot sick trees, so would go along with Derek and slip pot only for now. I often raise pots up on some grillwork to let them drain more freely. Good luck with it!
It’s an interesting subject for sure..I’ve read about it and I think it does not manifest into an issue for me as I tend to use oversized pots and repot them before the root ball starts getting too far down into the lower 1/3 of the pot..although I admit sometimes the crocks and ball come out as one unit!! @emery Out of interest do you not use crocks? BTW the pots only exist between November and March lol
Surely I'm not the only one who had an LOL at crocks and balls as a unit!! <sorry!> Anyway, no crocks for me. But the truth is I'm not a paragon of container gardening: my idea is to get as much root as possible in order to get maples into the ground, so I rarely go over 15-25 l pots. I did try crocks, and other substances like gravel, in the bottom of pots, but my maples really didn't like it. This was a long time ago, and like most of us I struggled for a while to find the right substrate for my locale. I use a high percentage of pozzolan mixed with other ingredients, so the pots are very heavy and don't blow over much. But I use that 1 substrate throughout the pot.
I use crocks also, but not as deep as @dicky5ash . If you go straight from large crocks to your potting medium you will not get a perched water table because the medium will trickle into the voids between the crocks and create wicks of medium going down to the base layer. The perched water table effect only really happens if you have a layer of grit or gravel or similar on top of the crocks that keeps the soil medium and the crocks apart.
The 3-6” deep of crocks I mention are in 60 - 200 ltr pots. Only 2” in smaller pots..I don’t top with gravel
I'm quite heartened by the lively discussion that's been engendered! Thanks, everyone for your input. I gather that the issue of crocks or filler at the bottom of the pot is a bit of a contentious one. And I accept that contrary opinions are supported by personal experience. My container is fairly large--I estimate 40-50 litres--so I expect that the roots might not yet reach the bottom of the container. At any rate, it seems that (in)adequate drainage is the main issue. I worry that if don't put coarse substrate (e.g. crocks) at the bottom, the potting mix will eventually occlude the drainage holes. Is this the main reason for the crocks or other coarse material at the bottom? I'm planning on slip potting in the next few days. I'm just uncertain as to the necessity of putting in crocks or other coarse material at the bottom.
I place a curved crock over each hole only, this is to allow water to drain and not clog up the hole with soil. All course material, ie grit, horticultural pine bark, perlite etc is in the total mix and not put at the bottom. I have found this to be the best method for good drainage for my maples. But of course, others have used different methods with success.
Dr. Chalker-Scott addresses pot shards quite directly. She notes that the coarser the material underneath, the more water flow is inhibited: i.e. a layer of gravel at the bottom inhibits drainage more than a layer of sand. She specifically addresses pot shards (only) but in a fairly anecdotal way. From this argument it doesn't follow, as far as I can see, that a single pot shard to keep the hole clear (as Derek does) would then raise the water table. @maf I'm not sure I hold with your logic, but Dr. Linda seems to disagree. Still, hard to argue with results! https://puyallup.wsu.edu/wp-content/uploads/sites/403/2015/03/container-drainage.pdf I use black plastic horticultural pots of type "SP" which I buy in bulk from Poland. They are max drainage, with many holes and angle and side drains, with several raised sections on the bottom. The only disadvantage (aside from the usual with black plastic, heat) is that slugs like to crawl up inside them.
In practice the crocks method holds the water table at the same level as Derek's single crock or even no crock at all. The saturated soil zone will be a fixed height depending on the soil make up, in the pot with lots of crocks that saturated soil occupies the zone in and around the crocks. In Dr Linda's example with layers of material keeping the soil from intertwining the crocks the water table will indeed be perched. See my expertly prepared, ultra-realistic technical diagram:
What is lacking in realism you more than make up for with clarity of illustration! I elected to slip pot the tree today, removing the landscaping fabric (good riddance!) and using no filler of any kind at the bottom. I unfortunately was unable to drill more drain holes into the container (it's fairly thick-gauge galvanized steel), but the existing central hole appeared to be patent. I did also add some perlite to the potting soil with a view to promoting drainage/aeration. To my novice eyes, the roots looked to be in fairly good health--not wet or friable. A few of the distal roots did appear to have penetrated the landscaping fabric and unfortunately had to be sacrificed. I look forward to updating you all on the eventual outcome!
and just to touch on the placement of the orange dream.. Our specimen is now basically in complete shade. It was in a sheltered north facing location for close to 20 years in a container with approx 2-3 hours sun / day. Spring flush was always very beautiful and then by mid July the brown tips overwhelmed the entire tree. The past two years it has not had the issue as now it virtually gets no sun with perhaps a little filtered sunlight from the larger canopy above it for an hour or two. It still opens up with the same beautiful spring colours and a nice fall presentation as well. I find the orange dream is even more sensitive then the full moon when it comes to sunlight. Also in regards to your location @jlrichmond , The area of Richmond BC is prune to fairly strong winds which no japanese maples like or really can sustain. We delivered and planted ( container and in ground) many japanese maples over the years into Richmond and we always stressed to keep the trees on the east side of homes for morning sun and minimal wind exposure.
and crocks? personally have never used any in all of our potted maples. I can see how in theory it can keep the drain hole from plugging. Our rule of thumb is a mininum 5 one inch (2 1/2 cm) holes drilled into the bottom of any container we use. One hole in the center with 4 closer to the edge of the pots. Occasionally we have used clear washed larger round gravel / rocks ( 1 -2 inches) in the bottom of large cement pots that are too difficult to drill extra holes into. This sangu kaku has been in the cement pot for over 20 years, will likely root prune next feb (2023) for the very first time.
Very nice sango, and I'm surprised that 20+ years later, it's still holding the coral color that well. My experience is that over time, they all start looking like plain mountain maples. Random question: do you water those pots by hand each day? Or do you have sprinklers set up on the patio?
We have always watered by hand. Generally about 30 minutes a day to water all the containers thru out our property each morning unless raining of course. I find you get a real feel for how much water the plants need on a daily basis depending on weather conditions. Even during our nursery operation years everything was watered by hand daily. Over two hours a day back then.
This is what single handedly prevents me from growing potted maples on my patio. Everything is in ground, with a small number of plastic potted maples on the ground near sprinkler heads. I can't imagine putting that much effort into watering them each day!
Well, look at it as a form of meditation to start your day! My wife and I love watering the plants. Also we visually inspect as well to keep on top of any tree issues, listen to all the song birds, and talk to our dog that follows with each step.
How absolutely wonderful Otto. My wife and I do much the same here in little old England, early morning out in the garden watering and with a first cup of coffee sitting listening to the birds and enjoying our trees. The perfect start to the day.
