Growing sweet peas

No English cottage garden would be complete without some structure draped in sweet peas, as a climber they’ll get up anything that they can get their tendrils round. They’re easy to sow and easy to grow and they’ll produce months of flowers as long as you keep removing the ones that are already there. It does mean that you’ll be picking them very regularly but as they’re beautiful and fairly ephemeral you it shouldn’t be much of a chore.

As they’re mostly grown as a hardy annual because we see many of the available seeds are Lathyrus odoratus they can be sown in either Autumn or Spring. There are perennial sweet peas such as Lathyrus latifolius commonly known as the everlasting pea is one, not as fragrant as the L. odoratus as the name would suggest but still a real looker.

Spring sown Sweet Peas

Here are the ones that were planted several weeks ago are now coming through and will be on their way to big healthy plants in no time. They’ve been in the greenhouse that until the last week has been getting quite warm during the days with only a few frosts, right now they’re sat in -2 degrees but still quite alright out of the wind and snow.

Autumn sown Sweet Peas

These are the ones that I planted in back in November and as we’re coming to the end of February you can really see how much  more advanced they are. If you plant them now you’ll still get the same sized plants and all the flowers that you’ll need but you’ll just have them starting a bit later.

Sowing sweet Peas

Like I said Sweet Peas are really easy to grow, there are a few definite things that you need to know. Some of the more common rumours around soaking them or scarifying (nicking, sanding or soaking) the seeds before planting I’ve never needed to do. There maybe cases when this can have an advantage but when you put the seeds in damp soil they’re going to grow if they’re warm enough and the seed is viable.

Things that are a definite advantage to note are that they have a long root system and that they’ll grow leggy, especially the early sown ones if you don’t pinch out the growing shoot.

Root trainers

Sweet peas

I use root trainers for getting mine growing, what I’ve not shown is that the roots are another 6 inches long when the trays are picked up, happily growing away in the damp gravel. It’s not going to kill the plants to do them in shallower pots but the restricted roots will cause smaller plants. You can use toilet rolls to great effect as well but they will dry out the soil quicker so you’ll need to water them much, much more frequently.

Pinching out

All you need to do is snip or pinch off the growing shoot just above a node or side shoot as soon as there and 2 to 3 of them and the plant is about 6 inches tall. This will create a stockier plant and stop it becoming a floppy, unmanageable thing. This also creates more shoots for more flowers later on. This goes against the cordon method that I’ll talk about below but you can still go down that route later if you want to have show quality flower stems.


If you want to grow exhibition Sweet Peas then this is really best way of doing it, you’ll get less flowers but those that do come will be of the very best quality. You can do it on a similar wigwam or A frame that you would normally but you only grow one strong stem. Make sure that there is only one stem per plant, remove the weakest and allow just the one strongest stem to grow up the cane, tying it in every 12-18 inches, or more frequently if you like. Then as it grows remove all tendrils and side shoots, this will strengthen the stem and put more of the plants energy into the flowers as that is what you’re really after. When the plant reaches the top of the cans, 6 or 8 feet tall, untie them all the way down and lay them on the ground around the base of the frame. Then take 12 inches of the growing tip and tie it back onto a cane so that it will carry on growing up. All of the sweet peas should now be growing along the ground and up a cane of their own to allow them to get taller again. All you’re doing here is extending the height that the sweet peas can grow otherwise you’d need 20 foot canes and a very long ladder to get to the top.