[Europe] soil stays too wet too long causing root issues

[incubator01]

I was recommended by several european people to use Mediterranean soil for my citrus as it doesn't dry out too quickly and because the 5-1-1 soil won't work (we don't have the same kind of bark and it starts to compost and do nasty stuff)

I followed a guide from a dutch website https://www.allimone.nl/citrus-limon/  (which I had to purchase, since this pdf is not free) and in that guide they too recommended
- to cover the drainage hole of terracotta pot with something such as a piece of a broken terracotta pot
- add a thin layer of expanded clay pebbles to improve drainage
- use Mediterranean soil mixed with perlite
- water in summer : 1l for plants smaller than 0.5m and 4L for plants bigger than 1m each week (more if theres a heat wave)

turns out the core of the root ball is drying out faster than the soil around it, the soil in the entire container stays too wet so I'd need to wait 2 weeks but despite that root rot still happens.
Granted I am using for some plants pots that are too big, but for 3 I managed to get a pot that was about 5 - 10cm wider (no more than that) so that would be an appropriate upgrade. Yet these are suffering from the same problem too.

In response to these issues I first mixed my soil with a larger amount of perlite (30% or so) but the soil didn't dry out enough.
I started noticing leaf drop (as I posted in some earlier topics) and yellowing / browning branches and that told me root issues,
I repotted all of them and added another 30% pumice (4 - 8mm size was all I could find from a german bonsai shop on amazon ) to further improve drainage. While gently removing the root balls out of the soil, I noticed that the size of the root balls of some of them reduced , some even by 50%
I also removed the expanded clay pebbles as others here mentioned they do harm for citrus.
 
So my questions:
- since my drainage can no longer be improved because I already did what I could, how can I decrease the time for the soil to dry out? (we had a few weeks of hot sun but after that much cloudy and rainy weeks, during rain I place them under a roof outside so the soil doesn't get even more wet.
- watering amount: i know many will say this is difficult to answer, I even looked up a table to calculate how many galllons for the canopy size and that came close to the amount I  found in that PDF but I still think for a freshly bought citrus plant in a 20cm pot dimeter with height of 60cm of plant (as mentioned on the site of oscar tintori) that 1 liter / week is too much. I started giving 0.5 liter but still seems to be too much. soil won't dry. (it feels dry on the top until the first knuckle of my finger and moist below that, never wet or sopping wet, but moist for so long is not good for citrus)
Is is perhaps a better idea to water 250ml with an accurate cup in the center of the root ball / week so it gets less water and should be dry by the next week?
Because, I know many will say "water only when it's dry or when you need to, not at regular intervals" and that's fine for me too but if my plant has root issues from this then I don't agree.

PS: the shards to cove the holes I use are not flat, they allow water to freely leak out, because they're somewhat curved. it's just to prevent the soil from clogging the hole.


Is there anything else I can do? I put them outside in the morning sun as much as possible but right now our summer is awful, the air humidity is high and we need more sun. and if it' not that then we get heat waves for which these young and now stressed plants are unable to withstand.
Side question: I have a pursha that was bought in a 30cm pot, this plant was bigger, but lost half its root ball due to heat wave (40+°C in greenhouse) it's still alive but losing a leaf or 2 a day, it's still has a lot of flowers and I was wondering if it's a good idea to remove them so he can concentrate on growing. I don't mind not having fruit next year, I want healthy plants.

[Sylvain]

Everything you tried or said is wrong. Sorry...
Citrus love water. The issue (probably phytophthora) is the lack of oxygen in the ground.
- don't use terracotta pots. Use plastic pots. make ~2 cm holes every 10 cm on the sides of the pot but completely at the most down place, against the bottom. Or buy pots that have this holes. The are becoming very common.
- use regular soil for plants and flowers that you find in any garden shop they keep water and drain enough. And nothing else! like bark, clay pebbles, perlite, pumice...
- never let your soil dry.
- always re-pot in a pot 4 cm wider (2 cm on each side).
- try not to move your pots or no more than twice a year to take them in and out.

Most of my citrus are always out side and believe me, they are very happy when it rains.

About your pursha:
- 40°C don't kill the roots
- loss of roots, loss of leaves and full of flowers means death is near.
Your citrus have phytophtora. To try to save them you might treat them with fosétyl-Al.
And you even are not sure to save them. 

[incubator01]

Everything you tried or said is wrong. Sorry...
Citrus love water. The issue (probably phytophthora) is the lack of oxygen in the ground.
- don't use terracotta pots. Use plastic pots. make ~2 cm holes every 10 cm on the sides of the pot but completely at the most down place, against the bottom. Or buy pots that have this holes. The are becoming very common.
- use regular soil for plants and flowers that you find in any garden shop they keep water and drain enough. And nothing else! like bark, clay pebbles, perlite, pumice...
- never let your soil dry.
- always re-pot in a pot 4 cm wider (2 cm on each side).
- try not to move your pots or no more than twice a year to take them in and out.

Most of my citrus are always out side and believe me, they are very happy when it rains.

About your pursha:
- 40°C don't kill the roots
- loss of roots, loss of leaves and full of flowers means death is near.
Your citrus have phytophtora. To try to save them you might treat them with fosétyl-Al.
And you even are not sure to save them. 

The heat definitely caused instant  leaf drop on the pursha and weakened him ever since, I was well informed here that such temperatures (especially the sudden-ness) was harmful for them.
I tried plastic pots for 2 years and it was much worse, the soil was more wet, using terracotta was a big improvement.
So I'm sorry but I do not have much faith in this information, just like i've been fed misinformation all over the internet from blogs and sites.
They're not beyond saving  just yet, in fact most don't drop leaves , just a few, and the kumquats that did recovered nicely in my greenhouse.

I just need a better way for my soil to dry a bit sooner. Even for a very small terracotta or plastic pot (12 cm diameter) for a small cutting needs time to dry out, so I do not find this normal.
I was thinking about using regular potting soil instead of Mediterranean but because several europeans recommended me that was better I used that....

[orangedays]

I am not an expert but I can relate some of my experience with root issues. If the citrus is in a large pot it is often hard to determine how wet or dry the soil is around the plants roots. I sometime grow a pepper plant or annual herb with thin sensitive leaves, in the same pot with a large citrus plant. When leaves lose turgor, the citrus needs to be watered enough to keep the pepper's leaves looking good but no extra water should be given. The tree doesn't suffer and it takes the guess work out of watering. I think watering a set amount is not good, you have to watch the plant's leaves and water when it indicates it needs water. Since citrus have thick leaves this is hard to detect. But a pepper is open about its requirements.

If the roots stays wet and are hot the roots will start to die. I have this trouble when my plants stay in the green house too long into the summer. The roots usually start dying off and a lot of root death can happen before the leaves start to show symptoms. But citrus are usually resilient and will grow back quickly if re-potted into fresh dry soil. Too high a ph will also be a problem for PT root stocks.

[Sylvain]

I already had 45°C/113°F in my green house and nothing happened.
Obviously, if the pots were dry the citrus would have died...

Indeed, everybody does as he wants. 

[incubator01]

I am not an expert but I can relate some of my experience with root issues. If the citrus is in a large pot it is often hard to determine how wet or dry the soil is around the plants roots. I sometime grow a pepper plant or annual herb with thin sensitive leaves, in the same pot with a large citrus plant. When leaves lose turgor, the citrus needs to be watered enough to keep the pepper's leaves looking good but no extra water should be given. The tree doesn't suffer and it takes the guess work out of watering. I think watering a set amount is not good, you have to watch the plant's leaves and water when it indicates it needs water. Since citrus have thick leaves this is hard to detect. But a pepper is open about its requirements.

If the roots stays wet and are hot the roots will start to die. I have this trouble when my plants stay in the green house too long into the summer. The roots usually start dying off and a lot of root death can happen before the leaves start to show symptoms. But citrus are usually resilient and will grow back quickly if re-potted into fresh dry soil. Too high a ph will also be a problem for PT root stocks.

Yes, I think keeping an eye on the leaves is my best bet along with the finger in the soil .
I know peppers very well, I grow them for 11 years, but I can't add one to a citrus pot because mine grow.....huge O.o especially Aji Amarillo's, these plants grow like jungle bushes.

For now they're all stable, leaves look happy, the plants that lost all their leaves (2 kumquats) have already regrown them in one month time (alemow rootstock).
The keraji on PT is currently planted in the greenhouse soil and is stabilised, but growth is very slow but I was aware of this and need to be patient, shikuwasa on PT is also stable, a month ago some new leaf buds shrivelled (dried out and turned brown) while all other leaves still looked good, but that was because of the sun / heat so I'll have to wait till next spring for new growth.
The pursha, I was already told this is a very sensitive plant, is currently also stable, I did remove a lot of flowers so he can concentrate on growing, but I merely started this topic because I found it so weird, after all I done to correct my past mistakes that the soil is still moist for so long but since the air is quite humid here, I think that's the problem right now, none of our plants seem to need water right now.
I just hope we get some more sun again and then things will get better.

[Radoslav]

My experiences from more than 15 years of growing citruses in pots.

1- I had the worst experiences with special soils for citrus, never use special citrus soil for citrus.
2- Its much harder to kill citrus plant with drought than by overwatering.
3- Citruses from supermerkets usually come alredy infected by phytophtora, in that case it does not matter how good your care is.
4- Size of pot does not matter.

[Millet]

Radosslav,  I find that the size of the pot does matter.

[incubator01]

Radosslav,  I find that the size of the pot does matter.

I agree.
I am well aware I made this mistake and I deeply regret it but I simply do not have the place to store so many different pots in different sizes, plus I was under orders
So I'll just have to deal with it and let the soil dry out as much as possible before the next watering.

For the pots that are too big, the surrounding soil stays moist even longer because the roots don't reach it, the smaller pots that were sized correctly (only a few) only recently dried out better due to a change in humidity in our air.
But right now we're having one of those moist hot weeks

[Radoslav]

I am using 60 to 120 litres pots for small plants to mimic open ground to induct the grow and never had any issue.
I am using Klasmann TS 3 with clay substrate, which is not originaly for such plants, but it works well.

[incubator01]

One of the soil suggestions I received from a nursery in Italy was the following:
- blond peat (about 60%)
- pumice (about 30%)
- some soil to get the right texture  (but he did not mention which soil) (about 10%)

Anyone's opinion on this?
I find this an awful lot of peat to be honest.

[pagnr]

I use 33% peat or coir/ coco peat, 67% coarse sand for seed propagation.
60% blonde peat, if that's young marsh peat seems high.
Some people use high % coco peat mixes, but there are quite a few grades of this available.
Marsh peat tends to be far more pH acidic than coir/coco peat, so high levels of this could be a problem in itself without pH adjustment.

[incubator01]

I use 33% peat or coir/ coco peat, 67% coarse sand for seed propagation.
60% blonde peat, if that's young marsh peat seems high.
Some people use high % coco peat mixes, but there are quite a few grades of this available.
Marsh peat tends to be far more pH acidic than coir/coco peat, so high levels of this could be a problem in itself without pH adjustment.

Ah, so this sand for seed propagation can also be used as "sand" to add texture in the soil for planting a purchased citrus tree in then?
Because often I read "add xx amount of sand", but when I went to the shop and bought course sand, this heavy sand absorbed so much water and was very heavy and did not prove well for drainage or aeration, and it remained wet for ages.
And yes, 60% peat seems very high to me as well, that is why I asked for opinions here

[Millet]

If "sand"  is used it must be quite coarse.  Children's sand box sand is not a good type to use.  Personally I do not use sand of any type.

[incubator01]

If "sand"  is used it must be quite coarse.  Children's sand box sand is not a good type to use.  Personally I do not use sand of any type.

Well, 3 years ago I found a Dutch website that discussed using 50% white sand and 50% compost, the white sand is indeed the childrens sand box type and it was awful, it kept sucking water in and did not drain, and the compost in containers caused fungus development too.
For reference here is the google translated site: https://translate.google.com/translate?sl=nl&tl=en&u=https://www.foodplanting.com/potgrond-voor-citrusbomen/

I've been through many of those miserable guides but if I can use the soil that you buy for seeds and cuttings instead and mix that with peat like pagnr said I should be better off because the Mediterranean soil I was advised is not suitable for our climate, you could compare ours to London. Wet well not always but right now they just said we have an extremely rainy and wet, humid summer

[JakeFruit]

Pool filter sand is a little expensive, but very course and drains well.

[incubator01]

Pool filter sand is a little expensive, but very course and drains well.

You mean this?
https://translate.google.com/translate?sl=nl&tl=en&u=https://poolshoproeselare.be/product/filterzand-2/

The 3.15MM - 5.6MM variant or the finer 0.4MM - 0.8MM  one?

Or do you mean this?
https://translate.google.com/translate?sl=nl&tl=en&u=https://www.toppy.nl/product/1197/filterglas-grof-25kg-alternatief-voor-filterzand.html

it's filterglass instead of filtersand but i read that's also used for propagation (not that I need to propagate but just asking )

[Millet]

Many people have tied to define or describe the ideal rooting medium for asexual propagation of cuttings.  In general it has been found that there is no ideal rooting medium, but several combinations of materials can provide a good, workable medium with a drainable pore space of 40% to 50%.  Good quality peat and coarse perlite, or peat and ground pine bark on a 1:1 or 1:1.5 basis by volume works well in propagation containers approximately 3.5 to 4 inches deep. If the pot is less than 2.5 inches deep, my advice is to not use it.  It is of upmost importance that the components of the rooting medium are free of disease and insects.  Good quality peat moss, although not sterile, is clean and ready for use directly from the bale, and has some capacity to suppress pathogens. By contrast, ground pine bark can range from relatively clean and acceptable for general use to containing soil, pathogens and weed seeds. DO NOT cut corners with respect to the rooting medium, as it is false prosperity.  Even with what you believe to be good Canadian peat and coarse perlite from a reputable supplier, always look at the materials and do not assume.  Over the years I have on a variety of occasions, opened a bale of peat and have judged it to be too fine and dusty to be suitable for propagation, as it would not drain well. Likewise, I have found bags of "coarse" perlite that were far from being coarse, and contained a lot of perlite dust 

The open wound at he base of the cutting combined with the warm, moist environment is an ideal environment for disease organisms.  This can be further complicated when cuttings are suck too deep and the open would is in the poorly drained area of the bottom of the container.
 (Taken from "Plant Production in Containers - Volume 2")

[pagnr]

I think this video gives a good run thru of the textures of various soil less pot mix components that are useful.
The size and grade of the individual granules gives texture.
You need to get a balance of water holding and AFP air filled porosity, which is air content of the mix.
https://www.youtube.com/watch?v=e0dnU6OgmkM
The sand I like is about the grade of coarse brown sugar.
In my climate I need a mix that can be watered daily, but not stay saturated.
For larger plants I use pine bark based mixes.

I don't use vermiculite anymore as it tends to float out onto the top with watering and is not as physically durable as harder items.

[lebmung]

PT is resistant to phytophthora spp so it doesn't have a problem with it. However it is sensitive to drought so not watering it enough may dry out and die.
High humidity, no sun, means no watering, all you need it to adapt watering to environment conditions.
Plants were moved too fast into big containers,, they start to make roots so it takes time, that's why for pots always increase size gradually.
PT as a rootstock is a slow grower, so you need patience.


One of the soil suggestions I received from a nursery in Italy was the following:
- blond peat (about 60%)
- pumice (about 30%)
- some soil to get the right texture  (but he did not mention which soil) (about 10%)
Lenzi uses this mixture, they have 10% garden soil, I wouldn't use it. Instead I would use humus or compost.

Blonde or white peat it's different from the general based black peat used in most of the mixtures that you can find in shops. Black peat retains much more water.

[incubator01]

I would like to give the following soil mix a try:
Cellmax terra soil mix
garden peat
brown peat
sphagnum peat
ground peat,
Coarse Perlite
Organic / Mineral Fertilizers.
pH (H2O) 5.0-6.5
EC 1.19 mS/cm
Organic/mineral plant food NPK 14-16-18. contains micronutrients
Water retention capacity: 600 ml/l

and add some more perlite, pumice and aquarium gravel to it:
https://www.amazon.de/-/en/Dehner-Decorative-Gravel-Aquarium-medium/dp/B01M5H2O7E/ref=sr_1_7?dchild=1&keywords=pflanzenkies&qid=1625591679&s=pet-supplies&sr=1-7&th=1

if that still retains one watering for weeks on end I don't know it anymore. Soil mix feels very lightweight though
and yes, unfortunately there is a limitation as to which components or materials I can get, even online. So sorry for not being able to get "just the right stuff".
I'll have to do a drainage and retention test with this later when I have time.

[Seanny]

Put a stake to the same height as a leaf so you can tell when the leaf droop.
Just wait it out and water when you see the leaf droop.
Formulate your watering schedule then.

[Millet]

incubator, seems like a lot of peat.

[incubator01]

incubator, seems like a lot of peat.

It is, but it will be better than the clay/bentonite granules that are inside the Mediterranean soil I have right now and from what I heard people didn't complain about the soil (so far, speaking about broad spectrum of plants, not citrus in general)

but that is why I do wish to add another portion of fine perlite (I can't find coarse perlite anywhere here but it's included in the mix), pumice and gravel to it to give more texture.
Coarse sand (also called drainage sand) was no option either, they only would ship it in a Bigbag of 1000 liters. and I have no use of so much sand.
I'll definitely reduce the amount of watering, that's for sure.

But on topic of Mediterranean soil, I know there are big differences in composition between brands, the ones I can get hold of are awful and compact easily. The one lebmung uses is much lighter and aerated and drains really good.

Like I said, I'll have to do a drainage and retention test without a plant in it to figure out how well it works before repotting anything in it.

[citrange]

Living in southern England I have very similar climate to yours in Belgium.
I have been growing citrus for very many years and I now always use the following mix which is very free draining but requires frequent watering in hot weather. It contains no nutrients so I add slow-release fertiliser granules initially and every spring. I also water always with dilute soluble fertilser. I have included some links to suppliers in the UK so you can see what I use but you can probably find equivalents locally.
Following parts by volume:
2 parts clay granules. This is a type of moler clay about 2mm diameter. It is sold for bonsai but is much cheaper to buy in quantity as Sanicat cat litter or as a chemical spill absorber. See https://www.safetyshop.com/clay-absorbent-granules-safety-tread.html and https://www.petsathome.com/shop/en/pets/kitty-friend-pink-absorbent-cat-litter-30-litre
1 part coarse pine bark sold as reptile bark or orchid bark. See https://www.ebay.co.uk/itm/265209292884?hash=item3dbfb4a854:g:MHYAAOSwbu1g14zU
1 part horticultural potting grit  see https://www.homebase.co.uk/rhs-horticultural-potting-grit-handy-pack-5kg/12812882.html
1 part coarse perlite This makes the mixture a bit lighter but can be omitted. See https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313&_nkw=coarse+perlite&_sacat=0