Sweet Peas

Normally we buy some sweet peas from garden centre as we did last year but said the seeds. Planted the seeds in unheated greenhouse and they germinated ok and once around 8" we planted them into a pot around a wigwam.
Now once that was done we decided not to put container straight outside as we thought they would be a bit tender, big mistake I think.
I know annuals are not frost hardy but did not realize sweet peas are not heat hardy!! We left container in greenhouse for a couple of weeks and then hardened them off before planting outside. Before planting outside the sweet peas started to look sorry for themselves and 2 died, I think it got too hot in greenhouse when sun was out. Now they are outside they are still looking sorry and may lose another 2, I think we should have put container out in the cool and perhaps not have this problem.
Anyway decided to try planting seeds this autumn in unheated greenhouse. Purchased 3 packs of seeds from grower recommended by sweet Pea Society and will have a go.
I did not realize how long the roots grow and was at first thinking of root trainers but too expensive since I will need cells for 60 seeds. A lot of people use cardboard toilet rolls but again I read since the peas are in them for around 5 months the cardboard can go mouldy and may affect the plants. I have some 150 mm (6") pots so may plant them in those or even some sort of plastic box or buckets minus the toilet rolls.

Anyone use the toilet rolls for sweet peas in autumn and if so did you get any problems? Or any other ideas?? I purchased Spencer seeds so although a long way off cannot wait to see what they are like.

 

I make pots from newspaper rolled around an aerosol can (some pictures on my blog). They are surprisingly durable (provided they don't actually sit in water). I make them quite tall - taller than the average loo-roll - and I think that is an advantage.

I don't see any benefit in sowing them in the Autumn. I have done that, they just sit and do nothing all winter. I now sow them early in the New Year - which means they are in their pots for a shorter time. I plant them out around about the beginning of April.

If you use look rolls or newspaper pots then make sure you remove the top of the "pot" when you plant out, otherwise the bit of paper/cardboard sticking out above the soil will act as a wick and dry the paper out, which will make it hard for the roots to grow through them.

When the seedlings have at least 4 pairs of leaves pinch the top out to leave 2 or 3 pairs, which will make the plant bush up. The initial leader that the seed produces is rarely the strongest, compared to the side shoots that are produced. If you are growing single-cordon then remove all but the strongest shoot when you plant them out.