Suburban Sue

Germination 5 - To soak or not to soak?

Well the weather over the last few days has given most of us no option of getting out without being soaked or blown away by a storm. Until I started looking at germination my understanding was that soaking is used for most peas and bean seeds. Does it work and what are the benefits and drawbacks of this way of starting seeds?


In looking at this I first looked at seed supplier instructions - none of them recommended soaking pea or broad bean seeds. This surprised me - old habits die hard! Myths and cultivation tips passed on by generations may have an element of truth but not be the whole truth or even have no scientific basis.


Looking at a variety of information there is some evidence that while soaking may help seeds to germinate quicker it doesn’t necessarily mean early or good quality plants. Some of the chemical changes brought about by over imbibing water appear to weaken the subsequent growth of the plant.


So why might we want to let peas and beans get a head start. Seeds are primed to take up water and germinate in the right conditions to allow them to become mature plants so whether the uptake of water is slow because less is available or faster from being soaked there are other factors at play.


Temperature - Peas and broad beans germinate at lower temperatures from 4OC to 18OC but don’t do so well when the temperature is warmer - this often means that they are sown early in spring and can be successfully sown through until May/June in the UK.


For French and Runner beans the temperature needs to be significantly higher for them to germinate which is why they are usually not sown in the UK until May indoors or June outdoors.


Oxygen

This is often forgotten as a requirement for seed germination. In some experiments there was a difference between viability of the subsequent plant between damp, soaking for 24, 48 and 72 hours with a significant decline in germination at 48 and 72 hours.


In waterlogged soil it may be best to start off indoors and then to plant out once the seedlings have established. Suggested methods are using a piece of guttering for peas and individual modules for Broad Beans


Mice, squirrels etc

Like a tasty snack especially in the winter months. The hope that the seeds will establish quicker with soaking doesn’t solve the problem of these pests. It is recommended that these are sown indoors either in the greenhouse, cold frame or cool room where they can be protected from pests.

Relax. If it works for you and you can sow in a timely way there’s nothing to stop you but if you don’t have the time, don’t worry. Seeds will germinate if you give them the right conditions so check them out before you sow.

The above information is all about our usual annuals and perennials both veg and flowers, however there are some seeds that may benefit from soaking such as some tree and aquatic plant seeds. For anything unusual check the germination instructions first!

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