Sunday, 8 September 2013

Growing Raspberries & Cranberries from Seed...


For some time, we'd been toying with the idea of growing soft fruit bushes from seeds – there's plenty of space on the greenhouse shelves for starting them off.   Growing fruit from seed is a fraction of the price of buying rootstocks, even if they're bare-rooted.  The major downside is that it may take much longer to get the plants established from seed.

It was actually more difficult to find seeds than established plants, although I had managed to find one eBay supplier based in Lithuania selling seeds for raspberries, blueberries, cranberries and blackcurrants, among others.  I suppose an even cheaper alternative may have been to buy some fresh fruit from the market and then prepare our own seeds from a few of them.

However, we ordered some raspberry and cranberry seeds for around £1 per packet, and they arrived at the beginning of June.  

Looking at the instructions provided for each type of fruit seed, they were both very similar.  To cool the seeds for at least a month, and preferably longer, presumably to fool them into thinking it's darkest winter from which they will then awaken and burst into life when the temperature is returned to normal.  This process is called 'stratification' by the horticulturists.



I must admit it all seemed a little fanciful and unnecessary - I mean, how would they propagate naturally in the absence of human intervention ?   So I immediately planted half of the raspberries in starter cells in the greenhouse, as I would with any other new seeds.  These became the 'control group', as it were.

I then (sort of...) followed the instructions supplied with the seeds and placed them onto a dampened kitchen sponge in a food container, before covering them with another damp sponge and then sealing the container and putting it at the back of the fridge.


seeds on the sponge in the container - 09 June 2013

It was then just a question of waiting....

After around seven weeks, in late July, I lost patience and removed the container from the fridge and planted out the seeds in a large aluminium dish.



large aluminium planter - raspberries in the right half...


So, how have they fared since then ?  Well, as of today, around half of the cranberries are showing encouraging signs of life with small shoots appearing.   However, only one of the raspberries has germinated as yet.


Cranberry seed shoots - quite a few of these....
Raspberry seed shoot - only one of these !

But, back to the control group of raspberry seeds which were not subjected to the initial cooling process.  Out of these twenty-four seeds planted, twelve of them have germinated so far and some have even grown to the stage where I've potted them on in 3" pots.


Raspberry plants seeds from the control group - some potted on.....

So, on the evidence, it seems the stratification process for the raspberry seeds was not only unnecessary, it was actually counter-productive, in that I now have a dozen established raspberry plants from the control group, but in the same timescale I have only one tiny shoot from the stratified group.   And with winter fast approaching, I'd expect the more established plants to have a better chance of survival until the spring.

I can't comment on the effect of the stratification on the cranberry seeds, because I foolishly didn't plant a control group for these - if I had, I might also have some established cranberry plants by now....

But we'll continue to nurture them all, and see what happens over the winter...


Update 03-May-14

Well, none of the very small seedlings from the 'stratified' group survived the winter, despite being under glass and the exceptionally mild weather we had.  

However, except for one, the established plants of the 'control' group all did OK in their pots in the greenhouse, and so today we've planted them all out after three weeks of hardening-off.  





So now let's see if we get any flowers and fruit this year....



Update 04-Oct-14

We've had a few handfuls of raspberries already, and hopefully still many more to come this autumn....








2 comments:

  1. I find that to be interesting. I've tried to germinate other seeds, roses, Mexican oregano, grapes and some others, all purchased through ebay and not one of the sellers suggested to stratify them before setting them to germinate. I have some blackberry seeds from the woods and some cranberry seeds from the fruits that I will try to stratify and see what happens but I don't have enough for a control. That was a good approach that you took!

    Bob (beachbassist@yahoo)

    ReplyDelete
    Replies
    1. The raspberry bushes are now two years old and four feet high ! I'm expecting a lot of fruit in the very near future....

      Delete