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Lockdown landscapes part 3: Collecting seeds

Updated: Jul 20, 2020

Continuing on from the propagation method we discussed in part 2 (plant dividing), collecting and growing seeds from your own garden is a great way of expanding your plant collection and preparing for next seasons vegetables. If you already have vegetables or flowers at the end of their growing cycle, then this is something you can easily do in this period of lockdown. This was once one of the most important jobs on the gardening calendar; today we are fortunate that (usually) we can buy them readily from the shop; but do we really need to?

Why collect seeds?

There are many benefits of collecting your own seeds – money saving is great, but you also have the benefit of knowing exactly what plant you will be growing next year. For instance, if you have some wonderfully productive and tasty vegetables, you can use the seed and hopefully get the same results next year! It’s a great time to get out and explore what you might have in your garden, gets the kids involved and educate them, as well as yourself about the lifecycle of a plant.

What type of seeds could I be collecting?

The easiest and most useful seeds to collect are those from your veggie garden. Plants which bear fruit, such as tomatoes, pumpkin, beans, capsicum and courgettes are collected from inside the fruit (you may even have some suitable seeds in your fridge). With other herbs and vegetables in the garden which are grown for the stem, leaves or root, such as lettuce, parsley, celery, parsnip and carrots, you will need to let them grow on until they flower and produce seed.

It’s also a good time to be looking out for seeds from your ornamental plants, such as poppies, foxgloves, delphiniums, granny’s bonnets and lupins to name just a few! Also tree seeds can be collected, but many seeds require special treatment before they will germinate.

Above: ripened seed pods of an Abutilon

How to collect seeds

The first step is to have a good look around and see which plants might be viable for seed collection. It’s best to identify the plant and do some research in case there are specific techniques for collecting seeds. An example of this is tomatoes and cucumbers which have a membrane around the seed itself. The seed requires the removal of this membrane in order to germinate, and the easiest way to do this is let the fruit rot away – the fermentation removes the membrane, the seed is left behind.

Other seeds may present themselves in a more or less ‘ready to use’ state. A good example of this is a poppy, which stores thousands of seeds in pods which ripen after flowering has finished. You can tell when they are ready to be collected as the pods will dry out and the seeds will rattle inside. These can be stored by collecting the pods, opening them up and emptying the seeds into a paper bag, envelope or folded into paper towels. Don’t forget to label them, so you know exactly what it is that you’ve collected, store them in a dry place until you are ready to sow them.

Above: Pumpkin seeds dry stored for the next growing season.

Sowing seeds

Again, the methods of sowing seeds can be quite specific to the plant which you collected them from. The main factors are timing of the season and how the plant is going to be used (i.e. for ornamental use or part of a formal edible garden). Edibles for the winter are on our mind at the moment. The likes of Broccoli, Cauliflower, Leeks, Spinach or Silverbeet. Leeks are fabulous to take seeds from and they can almost be planted all year round. You would just leave a couple to flower, collect the seed from their great big pompom flowers and sow them straight in the area you have chosen.

Seeds from ornamental plants such as foxgloves and poppies can be sown directly into garden beds in autumn or early spring. Some of the plants which we talked about earlier (with the example of poppies) can be sown directly from the pod, and broadcast over the garden beds. If you lightly cultivate the soil surface prior, this will increase the chances of germination. This technique is great for less formal garden beds or mass planting. The same seeds can also be planted into containers and started off in a glasshouse to be planted out later in the season. This is a good technique if you want to be more specific with your planting.

Above: Libertia seeds can be harvested from ripened pods. They self seed well so can be scattered directly onto garden beds to help fill gaps, or propagated in trays or pots.

The same goes for many of the seeds in your edible gardens. Planting directly into the soil at the correct time of year is a viable method – however, by the time the seeds germinate and slowly start to grow, you may have lost a valuable part of the growing season. The ideal thing to do is sow the seeds in pots or trays and grow them on in a glasshouse or cold frame. Planting out seedlings at the correct time will give you a head-start and extend the growing period, however seedlings will be tender so timing with the seasons is crucial. A good rule of thumb for summer vegetables is using Labour weekend in October as your guide. We generally do not have frost after this time of year. You may want to spread out your timing with seed sowing, so that all of your plants don't mature at the exact same time.

It's also great to have a go at growing some seeds inside the home, especially if you have young children. A seed tray or pot on the kitchen windowsill can be observed daily and helps get them excited about the prospect of growing plants.

Just like transplanting and dividing plants, the key thing with growing from seed is having a go. There is nothing to lose, so have a hunt around and see what seeds might be just outside your back door!

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