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Author Topic: How to keep citrus seedlings growing  (Read 961 times)

tve

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How to keep citrus seedlings growing
« on: March 03, 2020, 01:33:50 AM »
I've been rooting citrus cuttings for a number of years and recently started to germinate seeds. Plus I bought some C-35 and some Flying Dragon rootstock from four winds growers. Invariably I end up with problems when the seedlings get about a foot tall. Often it's my fault: I over-water or I forget one and under-water it, or I don't see the scale insects attacking the plant until it dies back.
Is there a "recipe for success" for watering these small plants and, related, is there a trick to get such stressed seedlings to get growing again? I've now had a couple that are about a foot tall, have 2-3 leaves, are green, but have not done anything in a year. Their roots are small but not rotten.

As potting mix I use half pumice and half the E.B./Stone citrus&palm mix (https://www.ebstone.org/products/eb-stone-organics?tab=outdoorsoilamendments#citrusandpalm-439) and I fertilize monthly with their citrus "plant food".

Some pics...
Here are 4x FD rootstock from 4Winds (left) and 4x C-35, received late january.


I repotted the FD as the roots were filling the tiny pots:


Unfortunately I didn't calculate the automatic watering correctly when I left for two weeks and the FD got overwatered as far as I can tell. (I should also have completely removed the very water retaining mix they were in as opposed to just filling my mix around the existing one.) Now I"m struggling to get them "restarted".. (Sorry for the bad photo with all the mess in the background.)


I've only recently started to use the transparent cups for the small plants after seeing that use on ourfigs.com. I need to put some paper wrappers around them to block the light, but so far there are not enough roots for this to be an issue :-(. The mix is very well draining but perhaps the 6 small holes in the cups are not enough. I'd love to experiment, but I find that it takes a very long time to see whether things are improving or not, typically the plant just sits there do nothing either way for a looong time...

Any help appreciated!

SeaWalnut

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Re: How to keep citrus seedlings growing
« Reply #1 on: March 03, 2020, 02:34:18 AM »
The trick with small pots its to water them once in a while until the water flushes out of the pot or else there could be salt build up.I also sprinkle somme gypsum or mix it in the water.
Welcome back on the forum!
« Last Edit: March 03, 2020, 07:08:26 PM by SeaWalnut »

Millet

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Re: How to keep citrus seedlings growing
« Reply #2 on: March 03, 2020, 11:13:48 AM »
Reading the information on E. B Stone mix, I see it is a mix of 6 ingredients.  Normally a mix should be made from no more than three ingredients, four at the very most,  I don't like a mix with both lava rock and pumice as is in E.B. Stone, plus you additionally add 50% more pumice .  Personally I would not  incorporate ether of them in any mix that I would use. Rapidly developing roots of seedlings with high respiration rates require oxygen levels greater than old plants.  When plants are watered excessively, the amount of oxygen diffusing to the root system is decreased.  The amount of carbon dioxide, on the other hand, is increased since the carbon dioxide comes from the living roots, bacteria and fungi.  If the carbon dioxide content alone reaches too high a level it can be toxic and cause the deterioration of roots of plants in containers. Because the column of growth medium is not continuous as soil is under field conditions, the water accumulates at the bottom of the container.  This restriction of downward flow of water occurs in a container with no bottom or with wire bottoms as well, since the drainage column is broken.  Therefore, the more shallow the container, the less growth medium in the top portion of the container that is well drained and suitable for good root growth. The more shallow the container, the more porous the growth medium must be  Likewise the deeper the container the smaller the pores can be within reasonable limits.  The desirable combination is a moderate depth container with a growth medium of moderate texture.  The drainable pore space for tree seedlings should be 25% to 35%.   Growth media that have worked well are 1:1 peat and perlite; 2:1:1 ground pine bark, peat and perlite, or 2:1:1 ground pine bark, peat and vermiculite.   
« Last Edit: March 03, 2020, 03:07:04 PM by Millet »

tve

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Re: How to keep citrus seedlings growing
« Reply #3 on: March 03, 2020, 12:45:03 PM »
Thanks for the replies! I hate working with perlite hence pumice, but I could report a couple of these little guys into 1:1 peat-perlite just to see. Questions:
- I would have to liquid fertilize or add slow-release fertilizer?
- How long should I expect to wait before seeing results either way? (They're in a greenhouse around 80F during the day and 55-60F at night in SoCal.)

I'm now wondering whether I concluded prematurely that they got overwatered and the issue is more like transplant shock. When I came back from my trip I took two out and examined roots and found the root ball soggy due to the original mix they came in, but I didn't really see rotten roots. The seedlings came in a very fibrous mix in pots (really more like tubes) 1" dia by 5" long. When I potted them up the roots had reached the bottom and formed a web mostly around the outside of the mix. I held them in the 24oz cups and filled my mix around the root ball. Mystery :-(

SeaWalnut

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Re: How to keep citrus seedlings growing
« Reply #4 on: March 03, 2020, 03:40:56 PM »
I added cow manure diluted with water 1:10  and wet with that after ive read what Millet wrote that they are heavy feeders .The trifoliate started to grow verry fast like 2 leaves a day.Its also in a small pot that gets really dry sometimes .
« Last Edit: March 03, 2020, 07:08:04 PM by SeaWalnut »

lebmung

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Re: How to keep citrus seedlings growing
« Reply #5 on: March 03, 2020, 05:45:22 PM »
Your soil mixture looks to me very draining.
PT and FD prefer a loam soil. In sandy soils with subtropical climates they perform poorly.
The peat structure and granulation matters as well.
40% compost, 10% sand, 25% peat, 25% coconut coir is good mixure if you plan to plant them in ground.
I don't like to contaminate my garden soil with perlite. Perlite is unknown potential lung carcinogen.
 
Quote
This product contains crystalline silica (less than 1%). OSHA considers perlite to be a nuisance dust. Inhalation of high amounts over long periods of nuisance dust may overload lung clearance mechanism and make the lungs more vulnerable to respiratory disease. Long term inhalation of crystalline silica dusts may cause lung cancer (Silicosis). Crystalline silica has been classified as a
probable human carcinogen (Group 2A) by IARC, a unit of the World Health Organization. This product has been classified a carcinogen by NTP and/or OSHA.
Not Regulated Potential Health Effects
Inhalation: Pre-existing upper respiratory and lung disease may be aggravated. Acute inhalation can cause dryness of the nasal passage and lung congestion, coughing and general throat irritation. Chronic inhalation of dust should be avoided.

When you mix raw perlite always use a FFP 3 mask. I think it should be banned to be used in garden. Over time it degrades into small particles which are blown by wind.

Millet

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Re: How to keep citrus seedlings growing
« Reply #6 on: March 03, 2020, 06:24:50 PM »
Lebmung, The University of Florida, and the University of California, the two big citrus Universities in the USA, both say when planting a citrus tree in the ground not to add any ingredients what so ever when back filling the hole other then the original dirt from digging the hole.

Laaz

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Re: How to keep citrus seedlings growing
« Reply #7 on: March 03, 2020, 07:04:07 PM »
Thanks for the replies! I hate working with perlite hence pumice, but I could report a couple of these little guys into 1:1 peat-perlite just to see

Use Turface MVP...

SeaWalnut

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Re: How to keep citrus seedlings growing
« Reply #8 on: March 03, 2020, 07:12:38 PM »
Perlite is as toxic as the glass wool thats used to insulate homes,walls,ceilings,etc.I dont like the perlite because it kills the earthworms.

Millet

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Re: How to keep citrus seedlings growing
« Reply #9 on: March 03, 2020, 10:40:55 PM »
Perlite is used as an ingredient in container mixes, and exceedingly rarely if ever used in the ground.  There are no worms in potting soils. 

SeaWalnut

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Re: How to keep citrus seedlings growing
« Reply #10 on: March 03, 2020, 10:48:31 PM »
Perlite is used as an ingredient in container mixes, and exceedingly rarely if ever used in the ground.  There are no worms in potting soils.
I like to add worms to pots and the perlite killed them all.
Worms in pots improove drainage,they make a lot of holes.
For drainage i think worms are better than perlite.

tve

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Re: How to keep citrus seedlings growing
« Reply #11 on: March 04, 2020, 12:39:38 AM »
Before this turns into a perlite war  ;D let me say that some of the plants will eventually find their way into the ground while others may stay in pots. I don't know yet :-).

Lebmung, isn't your formulation too water retaining while the plants are in pots? Also, what would you use instead of coco coir: I've banned it due to the risk of salts (ruined several years of veggie starts and potted citrus before figuring that out, it's not that the coir is bad per-se, it's that I don't know where I can buy "guaranteed" salt-free stuff).

I know there are lots of fans of Turface, I just can't bring myself to invest in that...

In terms of worms as a potting mix ingredient, funny thought, my experience is mostly that I can't keep-em out! (not that I'm trying)

SeaWalnut

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Re: How to keep citrus seedlings growing
« Reply #12 on: March 04, 2020, 02:46:41 AM »
To get rid of salt you can use gypsum.
Here we use it to recover the vegetation along the road after salt its spread on the roads in winter.
Its also good if you have a dog that pees on your lawn and burns patches of grass.It doesnt affect the ph of the soil and i think that gypsum for potted plants its really good ,especially if you have somme small pots and use drip irigation.
I had somme stagnant plants like yours,a few garcinia and an Inga wich after i added somme gypsum to the water ,they all started to recover.
« Last Edit: March 04, 2020, 04:12:48 AM by SeaWalnut »

Ilya11

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Re: How to keep citrus seedlings growing
« Reply #13 on: March 04, 2020, 12:00:50 PM »
For me these pots are too small relative to the plants size. The rootstocks were probably grown in the nursery by constant drip irrigation in this extremely draining substrate. I would replant them in larger pots with more humus containing soil.
Here in France some people have fairly good results with pots in which 2 cm round holes are made every 10 cm in the bottom part of pot walls. In such pots you can use even pure homemade compost without any root rot problems. The water is draining rapidly and you need it much less. 
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Walt

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Re: How to keep citrus seedlings growing
« Reply #14 on: March 04, 2020, 12:38:36 PM »
About 40 years ago I got a speck of perlite in my eye.  It was dust from the newly opened bag.  It was very painful, think of broken glass in your eye.  I had to go to an eye doctor to have the speck removed.  I've never tried it again.

SeaWalnut

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Re: How to keep citrus seedlings growing
« Reply #15 on: March 04, 2020, 01:28:20 PM »
About 40 years ago I got a speck of perlite in my eye.  It was dust from the newly opened bag.  It was very painful, think of broken glass in your eye.  I had to go to an eye doctor to have the speck removed.  I've never tried it again.
The perlite i bought had a warning not to rub your eyes while handling it on the bag.
Those tiny glass shards killed all my earthworms in the pots.

lebmung

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Re: How to keep citrus seedlings growing
« Reply #16 on: March 04, 2020, 03:24:06 PM »
Worms will kill your potted plants during the winter. I lost many plants because of them before.

Perlite is used as an ingredient in container mixes, and exceedingly rarely if ever used in the ground.  There are no worms in potting soils.
I like to add worms to pots and the perlite killed them all.
Worms in pots improove drainage,they make a lot of holes.
For drainage i think worms are better than perlite.

lebmung

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Re: How to keep citrus seedlings growing
« Reply #17 on: March 04, 2020, 03:38:13 PM »

Lebmung, isn't your formulation too water retaining while the plants are in pots? Also, what would you use instead of coco coir: I've banned it due to the risk of salts (ruined several years of veggie starts and potted citrus before figuring that out, it's not that the coir is bad per-se, it's that I don't know where I can buy "guaranteed" salt-free stuff).


You can substitute it with coarse peat, I am not sure if you can find it. Granulation is bigger over 20mm, so it has air pockets.
Compost made out of twigs and wood chips mixed with fresh grass it's the best, no other ingredients. It's fast draining and disease free. the only thing is that you need to do by yourself. Industrial compost or that found in bags is a nightmare.

Mixed perlite with peat in pots is not bad as long as is wet. I use it also for some root sensitive tropicals other than citrus.

I don't water the plants too much, then they do just fine if the pots dry out.

lebmung

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Re: How to keep citrus seedlings growing
« Reply #18 on: March 04, 2020, 03:42:07 PM »
I assume people here on this site know this. But I have seen people who polluted their garden soil with perlite. Or better said how many people think before they act

Lebmung, The University of Florida, and the University of California, the two big citrus Universities in the USA, both say when planting a citrus tree in the ground not to add any ingredients what so ever when back filling the hole other then the original dirt from digging the hole.

 

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