Protect Potted Maples from Heavy Rain

Discussion in 'Maples' started by BlackMaple, Jul 24, 2020.

  1. BlackMaple

    BlackMaple Member

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    I'm completely new to caring for plants. Having recently become "interested" in maples, but being the ruler of only a small, roof-less balcony, I am forced to stick to container gardening.

    That is why I'm wondering, whether I need to protect my potted trees from heavy rain in any particular way? Or can I just ignore these heavy summer showers, like we had yesterday? Should I be worried if before that, I just watered some of my maples? The limp pose of my hackonechloa grass shown below says it all.

    When planting the trees, I used pots with a watering hole at the bottom, coveredy by a shard, covered by clay pebbles, followed by a fleece, followed by the root ball.
     

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  2. Acerholic

    Acerholic Paragon of Plants Forums Moderator VCBF Cherry Scout Maple Society

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    Good afternoon @BlackMaple, I understand fully your concerns.
    The most important thing is that the water can drain away well. If the pots are sat directly onto a surface whereby the water cannot drain then they will become waterlogged very quickly and will often if they are young trees 'die'.
    What you need to do is place your pots on feet, most nurseries /garden centres sell these and they are not expensive at all.
    In the winter it is even more important to raise them. Remember that roots sat in wet compost without the chance to dry out will not receive the oxygen they need to live.
    There is a school of thought that you should not put anything in the pot other than compost with no pebbles etc etc. I do not go in for that, but you must be allowed to look at both sides of this argument.

    So first thing to do is raise those pots to allow for better drainage.
    Hope that's of some help to you.
     
  3. BlackMaple

    BlackMaple Member

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    As always, thank you @Acerholic ! With all my trees, I did a drainage test after potting. For all of them, water came out of the bottom. This is probably a stupid question, but if I have these few cm of pebbles at the bottom and water - maybe slowly - is coming out, do I still need to add additional feet? I.e. is it about speed of drainage or proper function?

    So another question, probably difficult to answer, but say I'm facing one week of rain on my balcony and the sail is constantly wet, should I then take extra measures, like rain covers, or will the plants be able to deal with a once-a-year, exceptional situation like that?
     
    Last edited: Jul 24, 2020
  4. Acerholic

    Acerholic Paragon of Plants Forums Moderator VCBF Cherry Scout Maple Society

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    @BlackMaple, you are right in that the substrate is correct for the plant and in this case Japanese maples. It must be a loose free draining compost that is IMO very close to an Alpine mix.
    Look at where these trees do well in Japan, they are on a shale like substrate that although they have very wet Summers and Winters the water drains very quickly. That is what you must recreate with your pots.
    To your next question, the answer is my first reply. They can handle plenty of Summer downpours as long as the water can drain freely. Planted in the ground, you would not go out and cover them up. You would ensure though that you have prepared the ground correctly to ensure they do not sit for long periods in water.
    So I still feel that you should raise your pots on feet as soon as possible and do not consider watering them until you have checked that the compost they are in feels dry.
    The rule of thumb is, if dry water and if moist or wet do not. Also it is important to check weather forecasts to ensure you do not soak your trees the day before the heavens open.
    Do come back if you are not happy with what I've suggested, or want more advice.
    Hope that's of help to you.
     
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  5. BlackMaple

    BlackMaple Member

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    Ok @Acerholic, will get me some feet then, thanks! I'm a bit ocd though, so one more question :)

    I read that maples are best kept "moist". So regarding your advice - to wait till the soil feels dry - does it apply to every watering, or only after heavy rain? Until now, I was sticking to the 3cm finger method, where I would start watering just before it starts feeling dry on the tip of my finger that far in. Does this distinction matter at all, or am I over analysing?
     
  6. Acerholic

    Acerholic Paragon of Plants Forums Moderator VCBF Cherry Scout Maple Society

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    @BlackMaple, no problem at all as many questions as you want.
    I prefer my maples to dry out enough to allow the roots to breath. Again think of the trees on the mountain side in Japan in mid Summer, no rain for a few weeks, do they suffer, no they don't. Too much water is a Japanese maples biggest problem. All the garden centres will tell you that maples must be kept moist, that IMO is strictly not true. I do not mean leave it in a pot and forget about it.
    Your method of the finger test is the closest you will come to getting it right so IMO you should stick with that. But do not religiously say every Sunday for instance think, Oh I must water today. That is where so many maples die. Check first EVERY TIME.
    Good luck and please update the thread with photos of your pots on feet.
     
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  7. BlackMaple

    BlackMaple Member

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    Thanks for your patience @Acerholic , I will post an update. I also do have the Vertrees Maple Guide coming in, which hopefully will teach me some more of the basics.
     
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  8. Acerholic

    Acerholic Paragon of Plants Forums Moderator VCBF Cherry Scout Maple Society

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  9. Margot

    Margot Generous Contributor 10 Years

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    Current thinking about the use of drainage materials in the bottom of pots strongly suggests that it is not a good idea. As Robert Pavlis notes on his Garden Myths website, Does Gravel at the Bottom of a Pot Help Drainage? - Garden Myths, "When water reaches the interface between two different types of soil – it stops moving." In other words, it impedes drainage rather than enhancing it. The water will drain out, but more slowly, especially if there is just one hole in the bottom of the pot.

    Where Japanese maples are concerned, the most important thing is that the pots are draining quickly enough during times of heavy rain. That can be determined by observing how fast water is coming out the bottoms and also by lifting the pots to see how heavy they feel. Obviously the water will not be blocked completely and root rot will not occur within an hour or two. Rather than try to protect your trees from the rain falling on them, I'd get rid of at least some of the drainage material, drill a few more holes and put feet under the pots as Acerholic suggested.

    I don't use rocks, clay shards or whatever in the bottom of pots anymore but I do cut a circle of landscape fabric instead to try and prevent soil from clogging the drainage holes or letting dirty water pool out on the deck.
     
    Last edited: Jul 24, 2020
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  10. zfrittz

    zfrittz Rising Contributor

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    I do not agree with the idea of not putting a drainage layer at the bottom of the pots.
    You just have to do a test, two equal pots one with a drain at the bottom of stones that are angular, that is, they are not smooth like river pebbles, they are mountain and the other only with substrate.
    The two are weighed, they are watered deeply, they are weighed again to see how much water they retain and after 5 days they are weighed again.
    Which would lose more water?
    surely the one with drainage layer.
     
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  11. Acerholic

    Acerholic Paragon of Plants Forums Moderator VCBF Cherry Scout Maple Society

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    @zfritz, I do the same as you J, but have been told on a few occasions on the forums that this is now looked on as wrong. Personal experience on this matter over my time growing maples will mean I will continue to do so though.
    I think its is a very good idea of yours that anyone considering either option should carry out the experiment you have suggested to enable them to make their own mind up. I hope @Margot would feel this is a good course of action to experiment themselves.
    I have advised @BlackMaple about the school of thought and he should consider both options.
     
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  12. emery

    emery Renowned Contributor Maple Society 10 Years

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  13. BlackMaple

    BlackMaple Member

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    Thanks for the input. Difficult subject. It could be true but I'm wondering if these studies have considered all the factors. For example, does having a fleece between the soil and the drainage material produce a different effect. Or, they always mention gravel, but around here we use clay pebbles for that. They have a much smoother surface, a hollow interior and a spongy effect.

    I will get me some transparent containers and do some testing. Besides that though, using clay pebbles also reduces the weight and as far as I understood, maples have shallow roots and don't require that deep of a container.
     
  14. Acerholic

    Acerholic Paragon of Plants Forums Moderator VCBF Cherry Scout Maple Society

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    @BlackMaple, good morning, science is a wonderful thing, but we all know after research by many scientists doing the same experiments they can and do come up with different conclusions.
    I agree with zfritz that you should carry out your own experiment and whatever drains the best in what you are using then go with that.
    As I said in my first reply to you, I feel you should be able to look at both sides of the argument.
    Do let us know your conclusions.
     
  15. ROEBUK

    ROEBUK Generous Contributor Maple Society 10 Years

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    Here's what i do regarding maples in containers , the majority of my potted out maples are all in black plastic containers ranging from 10 litre up to 200 litre but he average size of most is 45 litre , i only have two maples which are in earthenware/clay pots this is mainly due to the cost of potting out maples into expensive ceramics. Me personally i find the plastic ones more easy to manage re the the filling of large containers but most importantly the ease of which these can be moved safely. The ease also of adding additional drainage holes to plastic containers is also a simple procedure which takes minutes with a basic power drill and boring bits. Added some pictures of the holes i drill into all of my plastic pots , obviously the larger the pot the more holes it receives but all my pots have this method done first before anything gets placed in them. Again obviously you then need to prepare a free draining growing medium to be able to enable your tree to be happy in without drowning the thing!! this in itself is a topic in which we could talk about for ever.Experiment by all means until you find a happy medium. The ceramic pots i tend to find to be very cumbersome and difficult to work with especially when you have a larger trees which need to be in larger pots which is self explanatory, lets take for example a 50 ltr ceramic pot this can weigh in excess of 30kg before you have even put anything in it ? so by the time you have all your growing medium plus the tree and anything else you place on top this you can be looking at around 80kg + which is quite a dead weight to move or drag by yourself, plus the damage you may incur on your nice paved patio by dragging the pot over the top because you can't lift it. Then you also have the added financial outlay for buying your nice glazed ceramic pots, these things are not cheap!! have added some pics of a glazed 20 ltr pot which to my amazement it still had the price sticker on £25.99 and i have two of these!!! , must have bought these when times were good :) What you will also find with nice ceramic pots is they only usually come with the one pre cut hole which is done early in the production stage when the clay is still in it's wet stage prior to baking , any more holes and this will lead to excess cracking of the pot when in the kiln. This is easily again fixed with the aid of a drill with a 10mm masonry bit. One of the problems you also get with ceramic pots with the one based centre hole is it's usually on a convex base which allows for water retention so you do need to drill more holes to allow the water to drain , again you can see this problem on the pictures i have added , the one holed pot held 200ml of water on the base unable to escape through the one raised hole, added four more holes and then instant drainage. The only time i raise my containers off the ground is if it's over 100 litres again see pics
    Have well over 80 maples in plastic pots and two in ceramic (see pic) and to be honest all you need is good drainage holes and a good free flowing growing medium then you won't have any problems , for me i am more interested in whats growing in the pot rather than what the pot looks like, yes i do realise that some people have lovely patios balcony's etc and every thing must look neat and tidy and blend in with it's surroundings that's ok , it's just finding that happy medium for your own circumstances.
     

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    Last edited: Jul 25, 2020
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  16. Acerholic

    Acerholic Paragon of Plants Forums Moderator VCBF Cherry Scout Maple Society

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  17. Margot

    Margot Generous Contributor 10 Years

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    Another reason to raise pots off the ground is to prevent roots growing out through the drainage holes into the soil below.
     
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  18. Acerholic

    Acerholic Paragon of Plants Forums Moderator VCBF Cherry Scout Maple Society

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    @Margot, agreed Margot, I think that has happened to us all at sometime.
     
    Last edited: Jul 25, 2020
  19. AlainK

    AlainK Renowned Contributor Forums Moderator Maple Society 10 Years

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    I wish we had some !

    Otherwise, what ROEBUK posted is very good advice.

    I will add, or repeat, that Japanese maples like free-draining mix. If when you water your tree the soil takes 1,2,3 minutes for the water to run down the pot/soil, it's no good. In Austria, it should be easy to get pumice, or maybe pozzolane, or other. Add at least 50% inoganic medium to your mix and you won't have to bother about heavy rain.
     
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