Hi,i have a vainiglia pink orange dwarf in a terracotta pot.The new growth
is turning black from being over damp,so i have been told.We get a lot of
rain in Auckland new Zealand. Just wondering if i could solve my problems
by growing in chc 100%. I have tried with coir and that held too much water
too. All my trees have leaf drop then twig die back.
I thought i could remove half of the soil medium and then use 1/2 inch
chips plus slow release citrus fert.
Spring is fast approaching and my navelina,the above and my tangelo are
just hangin in there.
They are in a container mix at present which has those water storage
crytsals in it,with bark and grit,plus extra grit i added.The water passes
through quick but the soil stays wet for ages.
The new growth coming out as laterals all turn black and drop.
Thanks for any advice.

I wonder if this is a drainage problem or something else. The only thing I can think of that turns the foliage black is sooty mold. We could tell more if you could post a picture or give a more detailed description. Does other foliage turn black? Does the foliage die? Are any insects present (i.e. mites, aphids, scale)?

Could be associated with root rot. Have you inspected the root system ?

I feel Lazz may be correct. It sounds like root rot. I live in the Great lakes region of the U.S. we get lots of rain in the summer.

I feel your thoughts into using CHC is a good. Myself I use CHC and Peat mix, all my tree's are in containers and are placed outside on the deck in the summer. I have never had any problems with root rot from over watering, nor have I had any problems with under watering.

My friend Millet was the first to introduce this new concept a few years back. He released the information of using CHC and Peat after testing the mix on his own tree's.

CHC is also recyclable! I'm sure this would solve your root rot problems.

Maybe in the future Lazz could add a CHC Topic to the Forum.

Hi Dale, nice seeing you posting again. Actually, when a container constantly holds too much water over an extended period of time, what actually kills the roots is suffocation from a lack of oxygen in the soil. Yes, roots breath too. - Millet

thanks for your replies.millet,how could i remedy this please? is my idea
of using pure chc a good one.i tried chc/coir and had the same problem,i
think the coir stay wet a long time.i need to sort this out and then i can
watch my trees grow!
its the new growth coming out as laterals that turn black while small.the
older leaves are ok,although i have had some leaf drop.cheers

I mostly use CHC/peat, but I would not think that CHC/coir should cause a problem, unless you have to little CHC and too much coir, or too little CHC and too much peat. Is there any other ingredients other than CHC/coir? Also, what is the ratio of CHC to coir, and what is the CHC chip size that you used? Lastly how tall is the tree and how large is the container. - Millet

i used 1/2 inch chips 4 to 1 ratio chc/coir. It seemed too damp.
I have recently transplanted my tangelo to pure chc.I lost some roots and
the tree has been dormant but i hold hope for the tangelo.
My vainiglia pink orange is in a 27cm terracotta pot and is about one metre
high. It is in a container mix which has bark,peat,pumice and water storage
granules.The later is what i believe has been causing the trouble.The mix
takes ages to dry out.
I have a navelina in a 25cm pot just over a metre tall which i transplanted
2cm all around up from the original.It too had some leaf drop through
winter but is putting out new growth and flowers.This tree looks reasonable
but the pink looks a bit bare.
I am thinking of transpalnting now as its spring into a basic potting mix
which doesnt have those water storage granules,adding some pumice and
some coarse grit.The previous mix drained ok at the time but took ages
to dry out.Or i will transfer to pure chc 1/2 size and remove 2 0r 3 inches
around the root ball. cation exchange the chips.
I have a grapefruit too! again some leaf drop through winter,been quiet,
in the same mix and no growth at present.same height.All dwarf.
They are getting some nice sun now its warming up.
Anyway,they all seem to be holding water a bit.I tend to water once a month in winter. I have trouble with ants and aphids in the summer but i have ways to deal to them.Cheers

The CHC/coir mixed 4 parts CHC to 1 part coir, should cause no problems, even if the CHC/coir particles remains on the wetter side for a while, because that mixture would have at least 40 percent of its volume in large pore spaces (air spaces.) It is not the moisture that harms or kills the trees roots, it is the lack of air (oxygen) causing the roots to suffocate. When a tree grows in a tighter growth medium and is over watered, the amout of oxygen diffusing to the root system is decreased, whlle the amount of carbon dioxide, is increased since the carbon dioxide comes from the living roots, bacteria and fungi. There is evidence to suggest that the carbon dioxide content alone, if it reaches too high a level, can be toxic and cause the deterioration of roots growing inside containers. A 4:1 CHC/coir should contain more the adequate oxygen. I dont know about the gel crystals, I never use them. Gel crystals certainly would not be natural, and I wonder if the gel would reduce the oxygen around the roots themselves. About containers- because a container is a column of growth medium it is not continuous as soil is continuous under field conditions. Therefore a high water content ALWAYS accumulates at the bottom of the container. This high accumulation of water occurs even in containers with no bottom at all, since the drainage column is broken. Therefore, the more shallow the container, the LESS area of good root growth medium is available in the top of the container that is well drained and suitable for good root growth. Likewise, the deeper the container, the MORE area or good root growth medium that is going to be well drained and very suitable for root growth. The more shallow the container, the more porous the growth medium must be, and the deeper the container, the smaller the pores can be WITHIN REASONABLE LIMITS. Lastly, to avoid winter leaf drop keep the growing medium in the container at least to a temperature of 18C, 21C is better, or reduce the amount of direct sunlight upon the trees leaves if the root zone is kept cooler. Take care Laidback, you spring and summer are comming. Millet

thanks for the info,so what do you think of my idea to grow in pure 1/2
inch chips with slow release fert? have you ever tried? how could i minimise
shock going from a tight medium to a lose one? so,a deep pot would be
good for me then a? i was also thinking of using a cactus mix?any thoughts
please?how about adding coarse grit and pumice to my potting mix which
doesnt have the water storage granules?cheers

Growing citrus is not scientific nor should it be viewed in that manner. Citrus can be grown in all U.S States including Alaska.

There are many types of Citrus, some more cold hardy than others.

Laidback, I think you could possible grow a tree in 100 percent 1/2 inch CHC with great care, but the water would run through the pot so fast that it would not have time to absorb into the chip. You would have to soak the medium in a bucket of water each time, until the root growth filled up the air spaces. Also the roots might have to much air and suffer from air dehydration. Deep containers always drain better than shallow containers, and have a lot more prime root growing area. People grow citrus in cactus mix, and I guess they have good results, when the tree is given proper care. I have never grown a tree in cactus mix, so I can't give much advice in that area. I think a big container of cactus mix would be quite heavey. Coarse grit, or any coarse ingreadient, should help in the drainage and aeriation. Take care. - Millet

I took the vainiglia pink orange out of its pots today and it had some new
root growth but had filled the pot up which suprised me,since it had been
6 months since i had repotted.So,i put it in a 15 litre pot and used orchid
mix,which seems very free draining. I think this mix could be what im
looking for.I will keep you posted. I have a tangelo in 100 % chc and your
advice is noted about water absorbtion.I will soak it heavily.
Thanks for your help,i am determined to grow in pots and when i succeed
i will post my photos! cheers

Laidback, I ran a Leaching Fraction test on a 100 percent CHC growth medium. The CHC medium was a mix of 50 percent 1/4 inch and 50 percent 1/2 inch chips, with no other ingredients added. To obtain the percent leaching fraction, divide the amount of irrigation water applied to the container into the amount of leachate recovered from the container. (Leachate divided by Irrigaion water). The value for a 100% CHC medium was 91.25 percent. This percentage is the percent of water that passed through. Only 8.75 percent of the irigation water was retained by the 100 percent CHC medium. This is not good. You need to add some sort of a "filler" such as peat moss to slow the pass through down, or you will need to soak the medium in a larger bucket of water. If you soak the CHC's it will only take one minute, as they rehydrate exceedling fast. - Millet

I don't understand this leaching fraction test.

The amount of water absorbed or held in a container is fixed. The amount of water retained varies depending on the container medium and on how close to field capacity the container is when you start the watering. The rest of the water flows through and drains out.

I'm making up numbers, here, but consider the example of a 1 gallon container of CHC which starts dry and when saturated holds 100ml of water. You can alter the Leaching Fraction test result simply by pouring more water through. So 200ml of water poured through gives a 50% result (100ml of water retained, 100ml of excess water drains out). 400ml of water poured through gives a leaching fraction of 75%. One liter of water poured through gives a leaching fraction of 90%.

There must be some way of standardizing the leaching fraction test by the volume of the container. For example, if testing media in a one gallon container, use two gallons or four gallons.

Another good measure of container media is total and aeration porosity. This is easy to measure. Take a container and tape over the holes. Fill with water and measure the volume of the container. This is the total volume (TV). Empty the container and fill with growing medium. Now fill slowly with water until the water is at the top of the medium, measuring how much water has been added. This volume of water is the total pore volume (TPV). Total porosity % is TPV/TV and should be 60-70%. Now remove the tape and let the water drain out, measuring the volume. This amount is the aeration pore volume (APV). Aeration porosity % is APV/TV and should be at least 20%. Straight fir bark has an aeration porosity of over 50%. My guess is that straight CHC has a similar aeration porosity.