Collecting Seeds from Your Garden

Collecting seeds from your garden is not an intrinsically difficult task and is a fun thing to do (with or without children!). But – and you guessed there was a but – would you be surprised at the number of gardeners who collect seeds and then never do anything with them?

Yup. Time has been spent finding a good deal on new (empty) seed packets and purchasing them. Then collecting seeds from their garden plants to put into the seed packets. And then leaving them on the dresser next to the jug from grandma’s house because they’re not sure how to store them and anyway the family is demanding dinner.

The seed packets are found a couple of weeks later and the “Do I need to store these in the fridge or in the garden shed?” question raises its head. And the packets are left there until the matter has been decided…

And we haven’t even started on the question as to whether some of those seeds should be sown straight away. Or whether some could be sown now as well as next spring.

Let’s see if we can break this down into bite sized chunks of helpful information and ‘how to’ gardening tips.

Collecting seeds from your garden – before you start collecting

First question is why do you want to collect seeds? For example –

Because you want to save money (perhaps more relevant for vegetable seeds)
You like seed swopping with friends and / or charity
It’s not something you’ve done before and you fancy trying it
You’re planning on moving house and would like to collect seeds so you can grow the seeds into plants for your new garden (this could be sentimental reasons or practical or both)
The seeds are from a much loved relative or friend’s garden (you may just want one or two plants or be planning a memory flower border)
Perhaps you’re planning a new herbaceous flower border and want to grow some or all of the plants for it yourself
The seeds are a heritage variety

The reason for asking is to help you decide how important it is to you to be able to grow new plants and flowers from the seeds you collect. Because if it is really important, you will probably want to collect as much seed as you can and store in more than one place. That said, most seeds are remarkably resilient. Well, perhaps not remarkably, I mean it is in the plants best interest that their seed can cope with unfavourable environments before germinating. Its us humans that complicate matters by taking plants away from their native habitats and asking them to grow in our gardens instead.

What type of plant are you collecting seeds from?

Which is our second question. The reason for it is to do partly with the storage requirements and also with the later sowing and germination of the seeds.

What do I mean? Well, annual flowers and vegetables that are hardy and half-hardy are most likely to be tolerant of “less than perfect” techniques – ie, the methods most of us will be using. We are predominantly amateur gardeners with few resources such as specialised storage facilities, and there’s nothing wrong with that. My point is if you want to stretch yourself by trying difficult seeds, then do. But its perfectly fine to take the easy route.

Tender perennials that we treat as annuals will generally be easy to store. Many tree seeds, shrubs and exotic plants can be more problematic at the germination stage if they haven’t been stored correctly.

Quick clarification – yes it is possible to collect seeds from the herbaceous perennials growing in your garden not just from annual flowers. Although herbaceous perennials are more usually propagated by division (see blog link below) it can be fascinating to grow them from seed as well.

Plant Breeders Rights

You may see this on the plant label as PBR. Some plants are protected by Plant Breeders Rights which means that whilst you can take cuttings and divide plants for your own use in your garden, you are not allowed to sell the resulting new plants. (see glossary for more info, it should have come up as a window or clickable link)

What tools and equipment do you need?

You’ll be pleased to know that collecting seeds from your garden does not require anything fancy. Those seeds which require sterile equipment are not those you’re likely to be collecting.

Seed packets – the absolute minimum piece of kit! However these could be –

A clean (inside) used paper envelope. Re-using envelopes is frowned on in some circles but is fine to do. Many gardeners and allotment holders pride themselves on re-using and recycling.
Or purchase new seed packets online, from a garden centre or plant nursery.
Make your own seed packets from brown paper or plain, non-dyed paper

I say seed packets, but small paper boxes are good too. And can be easier for storing larger seeds such as runner beans. Glass jars are also successfully used by many gardeners (and see section below on drying)

The problem with plastic boxes is that they may cause the seeds to go mouldy. Seeds you purchase that are packaged in plastic or foil will have been treated / dried to prevent this. If its for short term storage because you’ll be planting the seeds in a month or so, then you should be fine.

Collection Day!

Whilst you’re collecting seeds from your garden, you may find paper bags, pots, jars, small bowls useful for putting the seed heads and seeds into.

Collecting seeds from your garden should be carried out on a dry day, obviously. But it makes sense to consider what the weather has been like for the past couple of days. If you have to collect when the seed head is still damp, then for example, cut seed heads off with a longer stem, so that you can hang them to air dry. Have the actual seedheads in a paper bag to catch seeds as they fall from the drying pod.

How do you know the seeds are ripe?

The seed pods will generally change colour from green to brown, black or red. Seeds should be collected when the pods are almost but not quite open. If they have started to open they are likely to scatter flower seeds everywhere as you try and collect them, making this task more problematic (but amusing for others to watch).

Other plants have their own seed collection issues. See me collecting honesty, Lunaria annua, seeds in the short video at the end – definitely amusing for others.

Not all seeds come in convenient pods or capsules. Some are stored within fleshy berries. Collect this seed by mashing the berries in a fine sieve and then rinsing away the pulp in cold water.

NB Calendula, the popular companion and bedding plant pot marigold, has seeds that should be collected when developed but still green.

Drying the seeds

About 80% of seeds needs to be dry in order to store and then germinate successfully. This includes most annual vegetable and flower seeds.
Air drying is the easiest method for home growers.

Larger seeds – spread on newspaper or kitchen towel and let them air-dry for about a week. If you can lay them out in an airing cupboard they’ll dry quicker. NB the seeds may well stick to the kitchen towel, but don’t panic, so long as that is also dry, it can be stored with the seeds (and indeed planted out with them too). I’m not as keen on using kitchen towel for this reason, but it is personal preference.

Smaller seeds – keep the seed capsule intact. You could just leave these in the bowl you used when gathering them from the plant.

If you’re short on space, or at least nowhere safe from curious cats, then all is not lost. Storing in paper and allowing air to circulate will allow residual moisture to be wicked out. One of the methods I have used is to hang the seed packets in a covered wire basket from a rafter in the shed. This allows them to air dry whilst keeping them safe from pests.

Do you need to store your seeds in glass jars straight away? A tip I’ve heard of but haven’t tried is to add dried milk powder. Wrap 1 -2 tablespoonfuls of powder in tissues and put this into the jar with the seeds. The milk powder takes up the moisture so it will need replacing in approximately 4 months (remember to check!) I might experiment with this method this year out of interest. If you’ve used it, I’d love to know how you got on (contact me via social media or email).

The “bendy seed” test

This is a quick way of checking the dryness of slightly larger seeds, such as beans. Carefully try bending the seed. If there is still ‘give’ then there is still moisture in the seed.

Where to store the seeds

For short-term storage, say 6 months to 2 years, its easy to keep your seeds viable. A place which is cool, dark, dry and free of pests is about all you need. It does not need to be the fridge. In fact for many of the annual flower and vegetable seeds that may reduce germination rate. This is due to different seeds needing different conditions in order to germinate.

Label the seed packets, jars etc with the plant and date of collection.

Should you store the seeds or sow them immediately?

Collecting seeds from your garden gives you the option of when to sow them, as not all seeds are available commercially year round. The blog links below give suggestions for seeds to sow in August.

One way to decide whether to sow seeds immediately or store them for later is to look around your garden and see if there are seedlings around the plants. For many plants it is good practise to let the ripe seeds germinate promptly, as soil conditions are favourable and it allows the plant’s progeny to get a head start on its competitors.

Why not experiment and sow a few now and the rest next spring? Keep some simple records to see which does better, remembering to include a few notes on weather conditions and so on for better comparison. It can be as simple or precise as you like, but it can be fascinating to try things out and discover more about your garden as you do so.

My flowers look different!

Will the new plants that you grow be the same as the parent you collected the seeds from? Ah, some of you are now surprised that they might not be – don’t worry, there’s a reason why this may happen.

Only species plants. which are basically those you’d find in the wild, are guaranteed to ‘come true’ from seed. (although they do sometimes send up a ‘sport’, but that’s another story!) A plant which is a species will only have two names, for example, Calendula officinalis (see Plant Species in the glossary for more info)

Therefore, if your aim is to have ‘the same’ plant as the parent then, when collecting seeds from your garden, you’ll need to only collect from species plants, not hybrids. Or, if its a perennial plant, propagate by vegetative methods,

But if you’re not too bothered, then growing on seed you‘ve collected from hybrid plants can be fun. The anticipation of wondering whether the flower will be white, or pale pink or something different again, appeals to many of us.

And lastly, remember that collecting seeds from your garden is a gardening event across many months of the year, not just in summertime.

How else can we inspire you?

If you would like help with becoming confident in collecting seeds from your garden, sowing and caring for them, we can offer themed gardening lessons arranged for the correct time of year to give you that knowledge, practice and confidence. why not get in touch? Plews is able to offer you individual, bespoke Gardening Lessons where your classroom is actually your own garden.

And for further gardening advice and inspiration, check out Plews Potting Shed blogs, including the selection below and our monthly Tipsheet – You could come and find us on Instagram Pinterest and Facebook too!