Seed Collecting and Cleaning Time 16 March 2021
By now you will be halfway through your seed collecting – see the table link below for rough guides to when particular seeds are ready to collect in Southland. As a rule of thumb the grasses are first (eg toe toe and red tussock), then the fleshy fruited seeds (Coprosma, wineberry) and lastly the seeds contained in capsules (eg Hebe, Pittosporum, manuka).
https://www.southlandcommunitynursery.org.nz/restoring-your-patch/get-growing/seeds/
Some seeds hang on for longer meaning there is not so much urgency in collecting but grassy seeds dispersed by winds can be gone quickly as can seeds contained in fruit – once birds get on to this source of food they can be gone in days, so be vigilent! Not all plants flower well each year and the big trees often have years off from seeding as seed production is an energy expensive action for plants, so often you wont find many seeds and other years will be bumper seed years.
Make sure you label the seeds collected at the collection stage as finding a rotten mass of old seeds at the bottom of your bag some time later and not knowing what they are isn’t much use (Note to self!).
Once collected (thorougly dry) pick out the chaff and store dry seeds in paper bags waiting for sowing later. For fruit covered seeds collect in plastic bags, label and later extract seeds from the fruit by pushing through a sieve, pouring water over and pouring off the fruity coat (the seeds should sink to the bottom). The seeds can then be shaken onto kitchen paper to dry and then bag to store or sow. This can be a time consuming process. See a few photos below of the process with Coprosma and wineberry seeds.
We tend to prepare all seeds collected over a few months then have a big sowing day where all the trays of mix and labels are prepared together and all seeds sown at one time, but you can do it piecemeal if you have the room and facilities to put them out in the Nursery. So around May you will need lots of space to put your seed trays and we have frames covered in shadecloth to keep seed trays safe (from cats and mice) over winter where they will sit until the end of September when seedlings start to germinate. It’s a combination of temperature and day length that are the natural triggers for seed germination. You can force germination (as commercial nurseries do), but then you need facilities to keep seedlings out of the frost over winter so we prefer to stick to natures schedule and it works for us! If the seed trays are outside but under shadecloth they will get watered whenever it rains. If you put seed trays in a tunnelhouse you will need to make sure they never dry out and thats a lot of effort and automated systems have to be watched closely. The seeds get stratified (cold treatment) naturally in Southland – there is no need to replicate winter by putting seeds in the fridge – they get a “real winter”. The germination seems to be like clockwork every year and most seeds germinate in September. However the seeds of the big trees like miro can take up to two years to germinate so hold onto those seeds trays for that amount of time.
Then, in spring its all on – everything needs to be done at the same time – pricking out, potting on, weeding etc so it’s the busiest time in the nursery but also the most enjoyable.
Have fun with your seed collecting – it’s a restful, quiet experience being close to nature. We will be doing seed collecting on Nursery Fridays to May if the weathers good for it.
Chris
Posted: 16 March 2021