In South Africa we are blessed with an abundance of indigenous flora. We often boast about the beauty of our fynbos but seldomly appreciate just how difficult it is to get the seed of these plants to grow.
These plants are so perfectly adapted to the fire-prone regions of the Western and Eastern Cape that their survival depends on frequent fires. Species belonging to the Proteaceae, Ericaceae and Asteraceae families require some form of extreme heat before they can germinate.
Seeds with this adaptation are known as ‘obligate seeders’, meaning their survival hinges on their seed’s ability to germinate after a fire has passed. Some seed, like eucalyptus, require the actual heat intensity from the fire to burst their capsules so they can grow. Other seed, like the fynbos vegetation, require the indirect, chemical effects from the burning to grow. In most cases, it is the latter that usually plays the larger role.
So, how do commercial growers solve this problem? Annual field burning would hardly be economical, never mind practical. Thankfully, the answer is quite simple: smoke seed primers.
These primers are specifically formulated with germination-inducing compounds that can be used to artificially treat seed. They benefit not only the obligate seeders like eucalyptus and proteas but can improve the germination of a range of seeds, including grasses and sedges.
Because growing plants from seed will likely be an important determinant in the success of your nursery, being able to maximize germination is a must! We at Agriculture Academy have done the hard work for you. Continue reading for all you need to know about treating seed with smoke paper to skyrocket your yields!
Before you begin, make sure you have:
One of the easiest ways to treat fire activated seed is to purchase a Seed Primer. We purchased ours from the Kirstenbosch National Botanical Garden. Click here to place your order.
No matter the primer you decide to use, remember to always read the instructions on the packaging before you start treating your seed.
The Kirstenbosch seed primer requires you to soak the green smoke paper discs in water. These discs are packed full of substances that mimic the physical and chemical effects of an actual fire. Leave the disks to soak until the water turns green and the discs become white.
Pour your seed directly into the smoke water and make sure that they are fully submerged in the solution. Agitate them a bit to make sure no clumps have formed and leave them to soak for 24 hours.
After your seed have been treated you can remove them from the smoke water. Keep them in a warm, sunny place to air dry.
Reuse it to make smoke vermiculite and double the use you will get out of the primer!
Your seed are now ready to be sowed into germination medium. We advise sowing your seeds in the location where they will germinate. Seed, especially very small varieties, can be blown off the surface of the medium with even the slightest wind.
With your trays lined up together, gently sprinkle the seeds over the surface of the growing medium. Make sure that you distribute the seed as evenly as possible. If you're unsure about how to sow very fine seed, read our blog post for everything you need to know.
Once all your seed has been sowed, irrigate your trays with a fine drizzle of water. Do not use sprayers with large droplets which can scatter your seed out of the trays.
Leave your trays in a warm environment and keep the soil moist. You should begin to see signs of germination in about 2 weeks.
Purchase your smoke primer from reputable sources. Do your research and make sure the retailers you are buying from are supplying you with the highest quality primer.
Do not over soak your seed in the smoke water. If left in water for too long, some seed may suffer damage. The recommended soaking time is anywhere between 8 to 24 hours, depending on the species of seed.
When drying out your seed after it has soaked, keep them in a still, breeze-free area. We recommend a sunny windowsill indoors with the window closed. You do not want all your hard work being undermined by a single gust of wind.