Lincolnshire,
United Kingdom 
Can anyone tell me why my container grown sweet peas alway go yellowy? The leaves are starting to look pale and sickly and the flowers as usually happens by now have dwindled considerably. I have started to feed them weekly as by now I assume the compost I set them in has less nutrient in. I also take off the pods as they form.
13 Jul, 2011
Answers
Thanks Drc, will try the nitrogen, at present I am feeding phostrogen!
13 Jul, 2011
Phostrogen should be fine - I would continue with it, as you have not long been feeding them?
13 Jul, 2011
sweet peas don't need a high nitrogen feed....they produce their own.
Any fertiliser should lean towards extra potassium and less nitrogen.
When did you sow your sweet peas? If they weren't overwintered or started off in February they will always sruggle, especially in containers.
13 Jul, 2011
Yes Legumes all make nitrogen in the right environment!
13 Jul, 2011
yes, i suppose a multipurpose compost has got no bacteria or fertiliser :)
Still doesn't mean you give more nitrogen than the others though. Chempak do a low nitrogen formula ( No 8) that is ideal for sweet peas.
Whenever i have to resort to a branded multipurpose compost i always add BTD fertiliser, nutrimate, and John Innes no3 to it, and sieve out all the rubbish.
14 Jul, 2011
Why not have a look at my sweet peas Scrumpy?
14 Jul, 2011
is this gonna be you show me yours, i'll show you mine?
Give us a link and i'll have a look.
I'll post a few more on my blog after my sweet pea show tomorrow.
14 Jul, 2011
There are in my photos Scrumpy.
14 Jul, 2011
Previous question
Compost is not going to feed your annuals for long if at all! This yellowing may be because you did not feed them, they do need a weekly feed, I give mine a high nitrogen (24%) feed I use the Miracle gro liquid one,
The reason they can look sickly? is mildew which is why its best to water only around the base.
13 Jul, 2011