Sad that fattening things like chocolate brownies, butter soaked flapjacks, and more come in such garden-useful containers, especially now, in the first fling of winter. The pic shows the sort of thing. Best are ones where the top half clips onto the lower half, and its edges overhang, or ever curl over, the edges of the lower one.
Large numbers of plant species from temperate or cooler climes still have seed whose germination is triggered by winter’s freezes and thaws. The sorbus species mentioned in the previous post, paeonies mentioned in an earlier one still, many irises, most primulas, many eryngiums, many, many alpine plants – gentians amongst them, roses, many fruit species and so on.
Alas, seed pods don’t come with sowing instructions printed on them, so it’s a matter of trial and error, or a bit of research. What have you found needs a good bit of winter chill? Let’s get a list together.
Right. Back to containers. Half fill the lower half with seed compost. Scatter a relevant quantity of seed. Here, the surface of the soil gets lightly turned so that some seeds get buried, others remain on the surface. With no directions to advise the gardener, it is impossible to know whether the seed needs light to germinate, or prefers depth and darkness. The light turning of the soil hedges the bets.
These ‘cookie’ containers are much better than normal pots, especially if you put the latter in plastic bags to keep weed seed out. Bad weather, at least here, flattens the bags into the pot, collects water, making a nice impermeable layer and ensure that what germinates rots soon afterwards. At the very least, the bags need some sort of internal support, however, that needs time and attention to detail. Their advantage is that the gardener doesn’t put on weight.
A label is put inside each, then the containers are clipped closed, put outdoors, and more or less forgotten. No weed seeds get in. The overhanging upper flap ensures no further water gets in. The cold does. Many sorts of seed need several freezes and thaws to unlock the processes that start off germination once spring comes.
The whole palaver is called ‘stratification’. It can be done in the fridge, in which case, and if containers filled with soil are going to cause a fuss, or take up too much room, dot seed over a damp kitchen paper towel, roll up, put in a freezer back, and label. In general, the seed only needs to be chilled, not deep frozen. Keep cold for a fortnight, bring back to room temperature for a week, then back into the fridge until you want the seed to germinate.
If you have supple and green fingers, the seed can be allowed to germinate still inside the rolled paper. Keep checking, and once the seed starts germinating, pick off the seedlings and plant out into trays.
All the above only scratches the absolute surface of the complexities of seed germination, a fascinating area of investigation. A faourite find here was a pocket of soil hidden away beneath a big daphne. It seemed to have accumulated at lot of Veratrum seeds, all of which seemed to be germinating in late September – so perhaps they needed a good summer as well as a cold preceding winter to unpick their lock. We rescued as many as we could before the slugs found them.