Cathy and I love Sweet Peas and we grow them every year. They seem to like the alkaline clay soil in the front garden and are much admired by passers-by. Our window cleaner also happens to be a champion sweet pea grower and he reckons it is because the place we grow them is where the mixer was when the extensions were done and each day the builders washed it out and the cement soaked into the ground in that spot. I am not sure I totally believe him but it’s a good theory!

We started with a small pot of mixed Grandifloras in 2009 and now grow several different cultivars including Cupani, Matucana and Painted Lady which, as far as I know, are the three oldest varieties.

Lathyrus odoratus ‘Painted Lady’,  (Photo credit: Wikipedia)

This year we participated in the Which? Gardening trial of ‘High Scent’ and have just reported back so I shouldn’t reveal the results until they do!

‘High Scent’

I have tried sowing them in autumn and spring and directly in the ground in April, and I have come to the conclusion that it all depends on the weather! In a mild winter and spring autumn sowing probably produces stronger plants and earlier flowers. The earliest I have managed is an overwintered self-sown white Grandiflora in flower on 24th April. However, in severe winters it is a struggle to keep them going, even in an insulated cold frame with fleece over at night. It is definitely better to grow them ‘hard’ but if the compost freezes for too long there are often casualties. It is strongly advisable to pinch out the growing tips when two pairs of leaves have formed, same for the side shoots, to keep the plants compact and bushy.

I have tried all the recommended germination techniques and read all the conflicting advice. There seem to be many contradictions in the ‘best practice’ expounded by the expert growers and it must be very confusing for some novices. Do you soak the seeds overnight in tepid water to soften the hard seed case? Or do you nick them with a knife or nail clippers or sandpaper them to expose the white pith beneath and ease the passage of root and shoot? Or do you, as I now do, just take them straight from the packet and sow them!

‘King Size Navy Blue’

Then there are the containers to sow them in. Should you use a standard 9cm pot, a discarded cardboard toilet roll tube, a root trainer, seed tray or what? Perhaps you should buy the special biodegradable grow pots from J. Arthur Bowers or special deep Sweet Pea Pots marketed so cleverly by Sarah Raven? I have tried them all but, in the end, I have opted for none of them. Instead, I have bought 100 re-usable polythene grow tubes for £5 from Eagle Sweet Peas as they seem to offer the best solution.

Although they will stand up on their own when full of compost, I can get 20 in a standard mushroom tray which keeps them upright and makes them easy to move about.

As the autumn sown seeds are going to be in the tubes for at least 5 months, I mix a little slow release food in the gritty compost.

The window cleaner reckons you should sow them when the clocks go back and plant them out when the clocks go forward. Simple to remember and has worked for him for over 30 years. Three seeds of each variety are now sitting in their grow tubes in the greenhouse and as soon as they germinate they will be transferred outside into the cold frame.  I will sow 3 more of each on New Year’s Day in the propagator, on 1 March in gentle heat if it is still cold, and directly in the ground on 1 May. If two thirds germinate and grow to maturity, bearing in mind how much slugs, snails, mice and birds love the seeds and seedlings, this should provide me with around 160 plants, half for us and half for friends and neighbours and the Horticultural Society Plant Sale in May. I am hoping to avoid the usual glut of flowers in June and July and prolong the season to provide cut flowers from mid-May to mid-September.

According to Mr Fothergill’s, 2013 is the year of the Sweet Pea and they have released a new variety in conjunction with the RHS called Chelsea Centenary to celebrate.

My 20 selected varieties for next year are as follows:

1. Cupani
2. Matucana
3. Painted Lady
4. Grandiflora purple/pink
5. Grandiflora red
6. King Size Navy Blue
7. Cathy
8. Heirloom mixed
9. Alan Titchmarsh
10. Apricot Sprite
11. High Scent
12. Singing the Blues
13. Henry Eckford
14. Ensign
15. Air Warden
16. Beaujolais Purple
17. Noel Sutton
18. Royal Family
19. Mrs R Bolton
20. Lathyrus chloranthus

Lathyrus chloranthus is a species variety and unique as it is the only ‘yellow’ sweet pea known to exist. It is a bit of a novelty and has little or no scent but I thought I would grow it simply for the colour which is really an acid green rather than yellow.