Hi there, I may have gone a little overboard for someone new to gardening and over the last few weeks purchased five small Japanese maples. They're between 14 and 36 inches tall. Atropurpureum in a 1 gallon container from a garden center Sango Kaku in a 1.5 gallon container from a garden center at a home improvement store Golden Full Moon or Autumn Moon, not sure exactly, in a small container from a local nursery and Shigarami and Aka Kawa Hime in small containers from acer1987 on eBay My biggest worry so far is overwatering them and so up until today I've been sticking my finger in the first few inches of soil to feel if it it's dry and then watering fully until the water runs out of the pots I moved them into. Each pot has at least 8 drain holes that I drilled in and the soil mix I'm using (3 parts potting mix, 2 parts pine/fir bark, 1 part pumice) seems pretty loose, and so the water drains out very quickly. I'll put a picture below of them in their pots with the containers they came in for comparison, in case the pots I chose are too large. I think the pot sizes I chose are pretty good except for maybe the Atropurpureum. The pot isn't much deeper than the one it came in, but is maybe too wide? Anyway, I wasn't happy with my finger sensor so I purchased a pretty cheap soil meter and used that today to check the moisture. In the small pots, the moisture reading pretty uniform from top to bottom between 4 and 5 out of 10, which seems about right based on the moisture I could feel with my finger. It's the same in the upper level of soil for the two larger pots, but at the bottom it jumps up to 10. I was worried that they were sitting in standing water or muddy soil or something, so I dug up some dirt from the bottom to see what it looked like. It's definitely damp and moist, but not "wet" - there's no actual water visible. If I squeeze the soil into a very tight ball I can feel moisture beginning to come out, but nothing really visible on my fingers at all. Definitely no standing water or mud or anything close to that. So long story short, my question is, is that level of moisture okay? I'm guessing it's that much higher according to the meter at the bottom of the larger pots because the roots haven't grown enough to absorb it from that low yet. Should they be moved to smaller pots? They've been in the two larger pots for 5 days or so and have only been getting a few hours of sun in the mornings since the weather lately has been a little unpredictable in terms of heat, so I left them in shade rather than risk them being in hot sun all day while I'm at work. My other question is about some crispiness on the leaves of the Sango Kaku and Aka Kawa Hime. There's a picture of the leaves on the Aka Kawa Hime below, the Sango Kaku has a similar look to its leaves. The Sango Kaku was out in the heat at the garden center and so I think that's why the leaves got a bit cooked. The Aka Kawa Hime was in shipment for 4 days so maybe that's why that one has some browning. Is there anything I should do other than keep making sure to water when the soil gets dry? Thank you so much for taking the time to read what became a fairly long post and for any advice you might have for me!
@crvxv Good morning, it is very easy to get a little paranoid over mapes and watering. But tbh if you have a good free draining soil in your pots and as you say you have drilled extra holes in the bottom, then over watering is not going to happen. It is only when people put their maples in the wrong type of soil and in pots that will not drain well that they get the problem of over watering. Regarding a few crispy leaves, I'm afraid this happens very often when they have been in a box for a few days. Also when at garden centres and they display them for people to see, that is often in full afternoon sun. So IMO you have nothing to be concerned with. Those crispy leaves will drop off btw, but that is nothing to be worried about. You will also get a second flush in a few weeks time.
I agree with Derek above but would add that I would decrease the frequency of watering of the maple in the large pot to encourage the roots into the damp lower compost as you know there is still moisture lower down.
Thank you both so much for the responses! My mind is a little more at ease haha. I wasn’t sure what to expect with the leaves so now I won’t panic if they start to drop off. And I’ll wait a little longer between watering the two larger pots and use the meter to keep an eye on the moisture. Thank you again!
as mentioned above, as long as you have the proper soil mix, and looking at your photo's I see a nice mulch based mix. That is ideal as you want good drainage. Maple do not like wet feet but they like regular watering in the container. Up here on the west coast of BC, once our container maples start to leaf we water every morning regardless of the size of the pot as a good soil mix will let the water run right thru. And no nicer activity then to check on the trees every morning while watering. If you are in a windy location in California combined with extremely hot weather then I would recommend watering twice a day during those periods. When we get a very hot high pressure ridge in the summer we apply that watering approach to all our containers as well.
There is one situation where you can have good drainage holes, well draining substrate and still build up water in the pot: if the pot undersurface is sits flush with hard undersurface, like concrete or stone, or a plastic table. In this case the water has no where to go. The solution is to raise the pot slightly onto something (gravel, a mat, whatever) so that the water can drain.
