With limited access to flower vegetable seedlings during lockdown, many gardeners have resorted to growing their plants from seed. Growing from seed is one of the most pleasurable and rewarding activities in the garden, starting with perusing online or hardcopy seed catalogues. Though it’s a trap for any plant enthusiast, as it’s quite normal to buy far more than you can plant in a season.
And this is where the first of my tips come in. To keep your seed fresh for more than one season, open the packet by trimming off the opposite end to the plant name so you can easily see what the packet is later. Take out the seed you need, fold the trimmed end tightly and clip it closed with a paperclip – those foldback black metal triangle-shaped ones are perfect for the job – and store in a cool, dark place.
The second tip comes into play as the seed gets older. Inevitably, the germination rate will decline. Some types of seeds lose viability in months, some take years, but in either case the rate of decline is not even. There will be some seeds that expire slower than others. Instead of wasting time and resources sowing unviable seed, an easy way of checking the germination rate is to spread the seed on one half of a moistened paper towel and fold the other half on top. Place the paper towel into a ziplock plastic bag and either include a label in the bag or write on the outside of the bag so you’ll remember what you’ve planted. Trust me, you will forget.
My seed bags go into the greenhouse on top of whatever is brewing under the bench (currently a drum of rum wash and a drum of persimmon wine). The temperature on these drums is usually in the mid-twenties at least. But any toasty, warm area will do. On top of the spa pool cover is another good spot, as is the hot water cupboard, but avoid direct sun as the seeds can cook in the plastic bags.
Start checking after a few days as some species (tomatoes for example) are very quick to germinate. You’ll first notice a little white hook shaped growth; this is the tap root emerging. Once you see this, you can carefully pick off the germinating seeds and plant them in your seed raising mix. Don’t worry if the seed leaves have started emerging as well, they’ll right themselves quite easily once planted. You will just need to handle them more carefully.
Each variety will germinate in its own time. Some will only take a few days to a week, others may take several months. Normally, what you will find is that annuals, such as most vegetables, annual flower crops and annual herbs will germinate within a couple of weeks at the most. Small-seeded perennials may take a little longer, while large-seeded perennials and many tree species can take much longer.
Usually, there will be a week or so between the first and the last seeds of each variety to germinate. Any that take longer than this I’ll usually discard as being weaker or unviable seed. If some of the seeds start developing mould, pick off the clean seed and transfer to a new paper towel, wash out the bag with hot water and discard the mouldy seed. If all or most of the seeds are going mouldy, then it is safe to assume the seeds are past their best.
As the seed in the packet ages, you’ll need to plant more to get the same number of seedlings each year. If very few or no seeds have emerged, then it’s time to discard the packet and order some fresh ones; and so the cycle starts again with the seed catalogues.