orange edges to geranium leaves

hi folks
im lucky enough to have a huge greenhouse full of geraniums that i care for in the day, which i have been doing for about a year or more now. when i first started they were neglected, pot-bound and had been in a similar state for the last 10 years or so.
i started feeding them and potting on as necessary and they responded really fabulously well last year, and had so much lush growth i had caterpillars the size of my little finger munching away.really that big!
anyways they overwintered in the heated greenhouse and entered the spring in a reasonably healthy state, i eased up on the feeding over the winter to maybe every 6 weeks or so,they needed it cos they were still growing in the heat,tho i did trim most of em back a bit. im feeding most of them around once a fortnight to once a week depending on size now.the once a week jobs are about 2-3 feet across.
my problem is that some of them are starting to develop really vivid orange edges to the leaves. it starts as very faint traces of lighter green round the edges which go to the centres looking a little like leaf miner trails, then it kinda looks like its been underfed(tho it hasnt). then it just goes vivid orange and reddish colours round the edge of the leaf.
ive tried flushing them through with rainwater (of which i have a plentiful supply) but it seems to have little affect.the ones ive been flushing ive stopped feeding. i feed with miracle gro, and i feed according to plant size (ie bigger plants get more,smaller less). if a plant is affected, all of the same type are affected (ie propagations of the same plant).

so

my question is... do you think im overfeeding and certain varieties are more susceptible or is it a ph problem in my water storage tank?

all opinions would be very much appreciated, ive been growing 15 years on a personal level,this is my first year doing it on a larger scale

 

G

Good morning forkhandles,
welcome to Gardeners Corner. Your post is a bit early for the geranium experts! But they will be up and about a bit later on. I love the smell of geraniums and I bet it smells wonderful in your GH when the sun comes out. Can you give us a photo or two ,with close up detail? Would love to view a long shot of all your plants too. We all love piccies

 

thank you jenny, i think you might have just answered my question,if its a bit early for geraniums then im probbly overfeeding, ive never had the luxury of a heated greenhouse before,ive normally overwintered my geraniums any way i can keep em alive,or at least dormant.
and yes it does get somewhat fragrant at times, specially when the lemons are flowering.
ive just seen the upload a file button, would have posted some pics already else...

first up a pic of the wafty leaves

 

heres the greenhouse, one end of which is the tomato house.
also one of the 3 to 4 foot geraniums which i potted up into a planter for the front doorstep later on..
the cold frame back at the end of march... its a little fuller now,my job for the next few weeks is to get it into the garden.
and some of the geraniums ive been growing up the back wall of the greenhouse. i aim to completely cover that wall this year. shouldnt take too long , last year they were only as high as the back shelf

ive got some nice shots of the greenhouse in full flower from last year if anyones interested...

 

and a couple of the cactii

 

A veritable paradise forkhandles. It is very apparent from these piccies that you are a true gardener who has great respect for the plants you grow. Thank you for inviting me round this morning. Very grey,wet and uncharitable in Battle as yet this morning. I would much prefer to be in your GH with your pooch. A little sweetie whose name is?
Jenny

 

thanks jenny, yes it is something of a paradise, even have the strelitzia to go with it :WINK1:
and growing is my passion but im just feeling my way really! ive kind of learnt to 'read' plants over the years,but even i was staggered at the way they grew. i was just giving them what they needed
and my dogs name is millie, a truly lucky individual who gets to enjoy herself in my gardens while i work. my clients love her, and she gets a treat everywhere she goes... shes perfected the 'cute' look

 

Lovely pics. of the flora and fauna forkhandles. Hiya, Millie - what a little squidgy! Please give her a hug from me today. I just love the vibes I am getting from your greenhouse,
thank you,

 

I agree with John ,I would not worry unduely, I would put it down more as a stress related problem which will sort itself out now light and heat levels improve . You can always remove the worst leaves if they are to unsightly.
Have they been kept very dry during the winter ,as I have seen this leaf colouring on older plants that have been very dry .
Love the photos ,and you certainly have a nice setup there ..
Dave

 

thanks guys, your input is much appreciated. im not too worried yet but i know how quickly little problems can turn into big problems if you dont get to them in time, especially in such a lush environment (most of those pics were from awhile ago. theyve grown on a bit since)... i will ease up on the feeding for awhile i think, and the problem will surely resolve itself when i next pot on.

yes jwk millie is a good little mouser too so she earns her treat in the greenhouse. mind you it didnt stop em running of with my first lot of tomato seeds and burying them in random places in the g/house as i discovered later when they germinated!

davy they have been watered over the winter and fed when it seemed appropriate. if anything there were a couple of occasions when i overwatered,tho when i realised i compensated and allowed them to dry out a little more between waterings. and i do deleafing in the greenhouse once a week, there really is a lot of geraniums in there. i might even count em one day

thanks for the welcome everyone, and the nice comments on the garden. it is a fabulous setup and all the facilities are there. i hope to do it justice this year. its looking mostly good so far...
ill let you know how i get on


and just for the record... millie gets a hug every day