Sounds like you may need to reformulate your growing medium. This topic is frequently discussed on the container forum and there is much useful information to be found there.

Thanks Tree Frog

I checked out the container forum and found a very interesting thread on container drainage. Lots of very helpful info . I am going to insert wicks through the drainage holes of my containers and monitor the progress.
Until I followed this thread I was not aware of the existence of Permanent Water Table in containers but relating to my current experience I am now sure that in each of my containers I have a lower layer of soil which is absolutely sodden.
Many thanks.

If you are going to go to the effort of installing wicks, you would be much better off to invest your time and a very small amount of money replacing the media around and under the rootball of your tree. Use something that is bark-based and chunky with pumice or akadama mixed in, very little or no peat. "Too wet" rarely has anything at all to do with water, and everything to do with pore spaces and aeration of the media. Also, keep in mind that all organic matter, bark included, breaks down and becomes finer and more compacted over time. Plants that are kept permanently in a container need to have the media refreshed every couple of years, or the perched water table and sodden situation will very likely return.

Susan

Hi,

Container growing has it's own set of requirements and issues from growing in the ground, watering and fertilization being the two main issues. Your maples may seem fine now, but root rot caused by overwatering takes some time to manifest visible symptoms.

I am with Treefrog and SilverVista on this. Container maples watered only once a week and still wet means your potting medium is retaining too much water. Wicks are okay I guess, but you really should correct the problem from the ground up, so to speak.

You really need to repot all your maples into more suitable potting material that has good drainage but will retain some moisture. Everyone has their own recipe for potting medium with regard to maples. A good mixture is 2 parts medium fir bark, 1 part sand, 1 part pumice or perlite. The amount of fir bark I need to buy is too much for my needs so I just use a ready made cactus mix that *doesn't* contain peat and that seems to be working fine. There is good drainage and good moisture retention. Also, I would advise to *not* keep your potted maples standing in pot saucers if you are. If you do empty the saucers after you're done watering. Dont' let the potted maples stand in the water in the saucers.

Next, get on a regular fertilization program. Every time you water your maples the nutrients are leeched out. Any good quality fert will do. Look for one that has lower nitrogen numbers relative to phosphorous and potassium, like 1-5-5, 4-10-10, etc. and one that has no nitrogen like 0-5-5 or 0-10-10. During the growing season use the 1-5-5 and about a month before fall sets in use the 0-10-10 to harden off the new growth before winter. Personally I prefer organic liquid ferts because *I* can control the amount and frequency, but pelleted organics will work fine too. I stay away from the time/controlled release chemical ferts like Osmocote/Multicote or granular chem. ferts. These are easy to use but also easy to overdo for certain plants and *you* really don't control the release of ferts.

Layne

Susan / Layne

Many thanks for the advice which I have taken onboard.

I have already started with the replacement of media and hopefully will have the operation completed in the next few days.

I noticed that you recommended ' little or no peat ' in the media , what is the reason for this ?

Also how often should I be fertilising and at what strength ?

Hi,

Dry peat moss takes a lot of water to saturate and once wet will stay wet for a long time. Aslo, it doesn't allow the pot to drain as quickly as fir bark. I wouldn't doubt that your current potting medium contains quite a bit of peat moss. Peat moss is good to add if you have plants that require more moisture retention like Papyrus, taro, or even azeleas to some moderation.

With regard to fertilizing: if you follow the directions on the container you'll be fine. However, the phrase "weakly weekly" is a good one. Half or quarter the dosage and fertilize half as often is probably better for the plant. The plant can only take up so much at one time and the rest is wasted. For instance, personally I use one liquid fert that directs me to dilute 4 TBS into a gallon of water, but instead I dilute 1 TBS into one or two gallons and apply this every other watering.

Hi Acercon3,

After looking at the ingredients on the package of the potting mix I use (Lilly Miller's Catcus mix) for my maples does in fact contain spagnum peat moss. My error. My maples still don't hold as much moisture as your's seems to though. My balcony faces west and I water the maples that get the most direct sun about every other day right now. The two maples in the shade get water about every 4th day. Temps are in the high 70s to mid 80s. Being that the mix is for cactus I don't think there is too much peat in it though I can't say for sure how much. Some peat is okay just not too much with regard to maples.

Layne