Tips for saving seeds in autumn

With autumn getting underway and many plants starting to shut down for the colder months, now is a good time to try saving seeds from your garden.  Like dividing existing plants, saving seeds is a great way to get lots of new plants for free – and it’s easier than you might think.

How do I save seeds for next year?

If you’d like to have a go at saving seeds from your garden, read on to find out how to do it, plus some suggestions for ideal plants to harvest seeds from in autumn.

Tips for saving seeds

Get your timing right

You need to collect seeds when they are just about to disperse, as this means they are ripe and therefore more likely to germinate.  Harvest too early and they won’t be ripe; harvest too late and they’ll be gone.

This is really a case of keeping an eye on the plants you’d like to take seeds from, and moving in when it looks like the seeds are about to scatter.

Ideal weather for saving seeds

It’s a good idea to collect seeds when the weather is dry, because you don’t really want them to come into contact with moisture before you sow them.  And if you’re collecting very ‘flyaway’ seeds then don’t try to do it when it’s windy! A calm, dry day is perfect.

Seed saving equipment

Saving seeds doesn’t need much in the way of equipment, but you will need some secateurs for snipping off the seedheads.  You’ll also need some envelopes or paper bags to store the seeds in. Don’t use plastic as this can harbour moisture, which is the enemy of seeds when it comes to saving them for next year.

Remember also to have a pen handy, so you can write the contents on each bag as soon as you fill it. I’ve learned the hard way not to leave this until later!

Seed saving techniques

Different plants make seeds in different ways, so you need to adapt your harvesting method to suit the plant.

Plants that make seed pods, like sweet peas, need to be harvested when the pods are dried, but before they split.  It’s easiest to cut off the whole pod, put it in the bag, and give it a shake to release the seeds.

Some plants form composite seed heads – cosmos, aquilegia and poppies are good examples of these.  Each head is full of seeds which, when ready to harvest, will fall out when you rub them. To harvest these, snip off the whole head and shake or rub the seeds out into the bag.

For plants whose seeds form inside berries, either remove the flesh leaving the seed (a sieve can be handy for doing this), or for waxy berries just sow the whole thing.

How to store seeds

Unless you’re planting them straight away, once you’ve collected your seeds you need to store them somewhere dry and cool.  If you’re not sure whether they have any moisture on them, lay out the seedheads to dry for a few days before putting them back in their bags. Keep the bags in a cool, dry place until you’re ready to plant them.

Popular plants to collect seeds from in autumn

Autumn isn’t the only time you can harvest seeds, but it’s the time of year when lots of plants will be at the right stage for you to do it. Here are some suggestions for ideal plants you can harvest seeds from in autumn.

Cosmos

Each flower will produce masses of decent-sized seeds, making this an easy one for kids to try harvesting.  Sow your seeds next spring.

Zinnia

Like cosmos, the flower heads produce the seeds, so rub these between your fingers to release them.  Sow next spring.

Sunflower

Another great one for kids to harvest. Sunflower seeds are big, easy to handle, and very obvious in the centre of the flower.  Each flower also produces loads of seeds, so you can leave lots for the local wildlife to enjoy too.

Astrantia

A fabulous plant for cottage garden borders, astrantia is ready to harvest when you see the seeds falling onto the outer petals of each flower.  You need to sow the seeds straight away, and they will need a period of cold to make them germinate, so if the weather is mild you might want to pop them in the fridge for a few weeks.  This may seem a bit odd and unhygienic, but as long as you put the tray or pot in a polythene bag you can keep things nice and clean!

Other popular garden flowers that are easy to collect seed from include poppies, larkspur, marigolds, nasturtiums and snapdragons. Remember to adapt your method to suit the way the plants make their seeds.

I hope you manage to save some seeds from your plants this season, there really is nothing like making new plants for free. And while we’re on that subject, you might like to bookmark my posts on dividing your plants to make new ones later on in winter, easy flowers to grow from seed, and the best tools for planting seeds. Have fun!

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