Harvesting Sweet pea seed

Saved ‘Piggy Sue’ seed

A new feature for Gather. I quite regularly get questions in my inbox on sowing, growing, nurturing and harvesting. I try and keep up with them as they come in, but it has just occurred to me that maybe I should share them. And so, welcome to Gather Q&A. The comments are open at the bottom of this post, so feel free to add to my answers, add questions of your own, or just put in your two pennyworth. All welcome.

Here’s our Q&A, from Julie.

Watermelon flowers & pods

Do you just let the sweet peas turn to seed on the main plant?

The short answer is yes. The slightly longer answer is also yes, but how this happens slightly depends on what you have been doing up until now.

The stock advice for sweet peas is to keep picking, because the setting of the seed stops the whole vine flowering. I am not sure this is quite as dramatic as everyone makes out. It was on Gardeners’ World last week that, if you were going on holiday for more than a few days, you should get a friend or neighbour in to harvest for you, lest you return to a tangle of bloom-less vines. I let every single one of my plants go to seed from the very start and they are still flowering at the top of the vine quite happily.

If you have been cutting a lot though, now would be the time to stop. It does take a little bit of time for the flower to get from peak bloom to a swollen pod, and the whole process will slow as the weather cools and the days shorten. There is something of a gamble with sweet pea seeds; you want them as brown and dry as possible, but before they twirl. Once they are open and scattering, it is very difficult indeed to catch the really good seeds before they fall to the ground. Too early though, and they simply won’t ripen enough (see below).

I pick the whole pod when they are toast coloured, hard to touch, opaque, and rattling slightly. I then dry in the pod indoors, then shell them, and then dry again in trays.

Then I will store them in jars in the fridge with with silica gel before I start sending them out to Gather people at Christmas.

A twirled pod

Heaven Scent, with ripe pods, unripe pods, and flowers

Juliet, ready for harvest this evening

How do you collect seeds while still producing flowers on the main plant?

 As part of the Seed Sovereignty training I am doing, I am in a WhatsApp group with some rather famous seed producers. They are almost exclusively vegetable growers, but many have cottoned onto the untapped potential for saving flower seed. However, the big growers have one model of seed saving; wait until a third of the seed crop is ripe and the first seeds are coming off freely, chop the plant off at the base, dry it in a polytunnel (I don’t have a polytunnel) thresh it, then put it through a big processing machine. This is called ‘determinate’ seed saving, which basically means ‘all at once’.

There was a flurry of consternation when Nicotiana was discussed. Nicotiana seed is like dust and sits in little cups along the flowering stem. Touch it and it scatters. The best case scenario is that it falls to the ground because you could catch it with a sheet, but nicotiana stems are sticky, and if the seeds stick to the plant, they aren’t ever going to go anywhere else. There was much back and forth about when to chop the plant, how to turn it upside down, what the timing should be etc.

I did not chip into this conversation because my method is different. I do ‘indeterminate’ seed saving. This means that, on a sunny evening, when I think about it (or when I have had a run on Nicotiana ‘Bronze Beauty’ orders, I potter out to the courtyard with a ramekin. Yes, a ramekin. I very meditatively and slowly inspect the seed pods to see which are empty and which are full and I very very carefully snip off the odd full one, being careful not to spill it, and then I turn it upside down and pour it into the ramekin. When I have enough, I stop. I did it on Tuesday this week and I shall probably do it again in a week or so’s time.

This is small scale, human seed harvesting, and almost all garden flowers will love this method. You get to keep the plant and the flowers to come, but you can also judge exactly which seed is ripe and pick it at exactly the right time.

Unless you are using my sweet pea seed to start your own seed company (and a few people are; there is more Piggy Sue being sold now than there were seeds before), I think you need a maximum of twenty seeds per sweet pea variety. Maybe fifty if you are planning to gift some as Christmas presents. Twenty sweet pea plants is a lot of flowers and twenty seeds is about four really good pods. Go out to your favourite plants, have a rummage at the bottom of the vine, I bet you’ll find the odd pod that you missed when you are cutting. If not, just leave a few now, and pretty quickly you will have more seed than you know what to do with. Once you have cut them, dry more than you ever thought possible. You only have to get them to October, and we can start the whole cycle again.

Will sweet peas turn to seed in a vase?

No. They won’t. Sweet peas need quite a lot of energy to swell the pod and cutting at a more juvenile stage of their development will simply mean immature, flat seeds. Sadly, one cannot have ones cake and eat it with sweet peas.

I am absolutely desperate to cut these Suzy Z flowers to bring into the house and photograph, but I didn’t sow enough of them and I want the seed more than I want the flowers so they are staying on the plant.

The good news is that you can with foxgloves.

Suzy Z. My new favourite.