problem with mums

[jaguarrh]

could someone please help, i've looked thru heaps of the posts and links in this forum but can't make my mind up as to what the problem is with my mums.

 

info:

 

these are aurora indica clones about 4-5 weeks old. after taking root in rockwool cubes i planted them into 120mm pots with 70% coco 30% perlite and put under 18/6 of 130W cfl.

 

they are hand watered with half strength canna vega nutes (don't have a meter i'm afraid) every second or third day (whenever it starts to feel dry when i push a pinky into the coco an inch or so). I mix the nutes 1 litre at a time and get the pH to around 5.5 - 6.0 (also don't have pH meter, i use the testing solution) and each litre lasts 3 or 4 waterings. i water until it shows in the tray beneath the pot, then for the next half hour or so continually empty any excess water out of the tray.

 

my room is well vented and the temps are steady at 23c-26c lights on and ambient temp at lights off (current lowest temp is 16.9c)

 

problem:

 

as you can see in the photos, the leaf tips are yellowing and generally curling up, predominantly at the bottom half of the plant. The newer growth is just showing a tiny amount of yellowing right at the very tips of the leaves.

 

the second mum in the background is a smaller plant, but was taken at the same time as the larger mum. she is also showing similar signs but much less pronounced. just the minute tips of the leaves are yellow.

 

any help would be great or if i can provide more info let me know

 

thanks

[Stoney]

from what i can see it looks like nute burn but u say u been using half strength canna nutes i would say give them a really good flush with just ph adjusted water and get yourself a ppm tester so you can be accurate with the nutes u are giving them it could also be a nute lockout but cant work out why from what u saying u been doing everything right

 

good luck hope they get better

 

cheers

[bongonaussie]

have you had a look at this

 

[WantDaChronic]

imo, you have 2 problems:

1) looks like they have a little nute burn

2) they look like they are in 1L pots...

 

my mothers are in 70/30 coco/perlite as well, half the lighting, but same nutes and everything else pretty much i know for a fact if those are 1L pots, you have at the most 2 weeks of good growth in them and although you can leave them for 4 weeks before you transplant them, the lower shade leaves will start dying and it'll work its way up the plant quick smart

 

IMO, what you need to do is transplant into larger pots and only feed once a week...the rest of the times you should just give them pH ajusted water with no nutrients and with coco its very important to give it a flush every 2-3 weeks to prevent any salts or pH "hot spots" from building up

[jaguarrh]

xlnt, thanks for the input folks.

 

have you had a look at this

 

yes bongon, i went thru that link, couldnt really say that any of the photos struck me as an identical problem. I am sure my problem is in that list, i just can't see which one.

 

stoney and wdc... i think i am leaning towards what you said, nute burn. i will give them a good flush today then let them settle for a while before changing to a once a week feed with less than half strength nutes and pH'd water between.

 

as far as pot size wdc, i want the mums to be bonsai ( i tipped one the other day) so what would be a good final size of pot for a bonsai mum? i intend to root prune periodically to allow for new growth in the root zone.

[thc24]

i grow bonzi mums in one liter pots, three about a month old same nute, simular light but trained .

 

the pots are well full so will be up graded to 8/10litre pots within days.

 

Feeding i normally feed every second day of either watered down res water or a fresh mix upto 2.0ec 2ml per litre.

 

you plant looks to have a few issues maby burning but the plant doesnt look too green, normally when you over feed plant gets greener and greener then burns, are you sure you didnt make a mistake with the nute maby doubled the dose. do what the peoples above suggest change the pot at same time have alook for damaged roots, give her a flush and start nutes straight away at 1ml for a week

 

Mums need good venting just like veging plants. Heat can do funny things to a plant.

 

 

good final size would be 40cm x 40cm x 40cm

 

My mums are 25cm x 25cm atm

[jaguarrh]

sorry thc, i think u misread me..

 

i meant what size pot is good for bonsai mums.

 

do i understand correctly that your mums are currently in one litre pots but you will be repotting them into 8/10 litre pots soon?

 

as far as i understand, a bonsai is usually kept in a smaller than ideal pot, as being root bound helps to keep the plant small. is this correct?

 

sorry for not quite following your post.

[jaguarrh]

everyone has probably seen this, but look at the size of these pots. they seem really small

 

originally from og

[thc24]

Id keep the mums smaller than in that pic other wise youll need MH of hps.

 

8 to 10 litre pots should keep the mum happy for 9 months.

[Tom]

and get the pH to around 5.5 - 6.0 (also don't have pH meter, i use the testing solution)

Coco PH should be 6.0 - 6.4, put the PH meter on the "important" list too as they can save you hours of pissing around.

 

I am using the same sort of media as you as well and running full strength nutrients (Canna Coco, EC 2.4) with no sign of nutrient burn so unless you have used one of those brands of coco that already loaded with fertilisers I would be more inclined to look at your problem as being PH related, I agree that they need to be in bigger pots too.