Raising seeds to seedlings

What is an heirloom seed?

Seeds used to be an inheritance (I think it's sad we have lost this tradition). The term is generally applied to seeds that produce a reliable crop year after year, and were produced over generations by open pollination. So these varieties are old and have stood the test of time. They are often a good producer (quantity wise) and where relevant store well. But each variety will have it's own benefits to read up on them.

If you want to save seeds from heirloom crops you must only grow one variety to avoid cross pollination by insects. For example, one variety of pumpkin. If you grow more than one variety, you will likely get cross pollinated pumpkins which means your seeds would be "hybrid".

There are no rules. And most people following are gardening for pleasure. But when buying heirloom seeds you are effectively purchasing a reliable and dependable crop. Worth the price tag.


What is seed raising mix and should you buy it?

A seed will germinate when there is an abundance of water, and has enough nutrients to survive for a few days and push it's way up to the surface of the soil.  But after this it is reliant on the soil and the nutrients and water that come from it.  Seed raising mix is designed to give seeds the best start in life and increase the likelihood of them surviving.  As well as that, it is designed to be "light" so seeds can easily push their way through it to the surface. 

You can purchase ready made seed raising mix, but you can also make it easily.  Mix potting mix and compost in equal parts and sieve them.  The compost will add nutrients and improve water retention, while the sieve will keep the mix light. 

It's a good idea to sieve store bought seed raising mix too. 

How many seeds do you plant?

The old saying is "one for the rook, one for the crow, one to die and one to grow." Although in Australia it's more like "one for the possum, one for the snail, one to thrive and one to fail". (Haha that's an original quote. I should copyright it).

So long story short plant at least 2 or 3 times as many plant as you want.

How deep do you plant seeds?

Seed depth is actually quite important. Too deep and the sprout may not get to the surface (the light) before it runs out of energy. Too shallow and it might dry out or fail to thrive because it's roots are too shallow.
Every seed packet will give you an idea about how deep to sow your seeds. All of my planting guides help tell you how deep to plant and take the guess work out of it.
But as a general guide, sow big seeds deeper and small seeds closer to the surface. I'd plant bigger seeds like beans in a hole second knuckle deep (3cm) and small seeds like carrots in a trench about first knuckle deep (1.5 - 2cm).

Should you soak your seeds before planting?


The idea behind soaking seeds is that seeds germinate when there is an abundance of moisture. By soaking them you are creating that abundance and they sprout faster. I did soak them once, but I was too busy to notice if they sprouted faster. I do not soak my seeds because I do not have the time, but here is how if you choose too.



With smaller seeds like carrots or cucumbers, you need to be careful when soaking. They are so small and soft that they can rot. So soak them overnight by placing them in a small dish with a tablespoon of water and plant them out the next day. I find it hard to plant small seeds like this when they are wet, and so thinning will be necessary. However, with seeds like this, because water can easily penetrate the seed, I think that there is little use in soaking as germination happens so quickly in the ground anyway. (Do your cucumbers take a while to germinate? This is more likely to do with soil temperature than soaking and water penetration. They like it hot and don't really get going until November in a cool climate.)


However, is a different case with seeds like peas, beans and beetroot. These seeds have a hard coating and a night of soaking helps them to breakdown and germinate faster. If you have the time to soak before planting, then there is a recognisable benefit in doing this for legumes and beetroot.


Why you must harden off your seedlings

What is hardening off?

It is the process of slowly introducing seedlings raised indoors, in a greenhouse or purchased from the nursery to the great outdoors.

Why should I harden off my seedlings?

Seeds raised indoors etc are used to different growing conditions than is present outdoors. This can be because it's hotter, colder, windier or drier. If you plant without hardening off, you risk your plants getting shocked and dying.

Even nursery seedlings?

Especially them! How many times have you bought seedlings, planted them, only for them to wilt, turn yellow or die? Commercially raised seedlings live amazing lives until you buy them. They are fertilised, watered and fed artificial light constantly. Imagine how they feel when you bring them home to your garden after this upbringing? It's no wonder they go into shock!

How do I do it?

Over the course of a week, place your seeds outdoors during the day and bring them back inside and night. Start in a shaded spot, then part shade and then full sun. Don't leave them outside overnight until a week has passed.

When should I do it?

Start around mid October so you plants are ready to be planted by Melbourne Cup Day.  (For those living in a cool climate like Canberra, Melbourne Cup Day and after is the traditional time to plant summer crops because it is almost certain there will be no more late frosts which can kill your seedlings.  If you live in a temperate climate you will be able to plant earlier).

Raising seeds to seedlings