Now that spring is almost upon us I thought I’d share the method I use to germinate Acacia Phlebophylla seeds. It has taken a few years of trial and error but now I have it down pat. I’ve got it to 90%+ germination rate all in the first month of spring. It certainly isn’t the only method but it works for me and I thought sharing might encourage others to give it a try.
I like to start the process early August (as it takes about 4 weeks for them to start germinating) to take full advantage of the spring/summer growing season.
I use a razor blade and take a tiny nick off the hilum end of the seed, this is where the root will come through. Be careful not to take too much off you only need to get through outer coat. Once they are all scarified I then soak them for 24hrs in previously boiled but COLD water. Boiling water at this point will kill your seeds if using this method.
After 24hrs and seeds have swelled up, I now put them in a plastic Chinese container between two sheets of damp paper towel (I like viva brand as it holds a lot more moisture than cheaper towel), all spaced out so they aren’t touching. I put the lid on and place them in the fridge.
They will germinate in the fridge and throw out a tap root but it normally takes about four to six weeks for the first ones to start. Once they grow their little root (2 or 3mm, don’t let it get too long) I pick them out of the container and put the rest back in the fridge, checking them every few days. It normally takes a few weeks for them all to germinate once they’ve started.
I then very carefully with a pair of tweezers peel off the outer coating of the seed and plant them in a seedling tray just under the soil with the root facing down. I put the seedling tray in the hothouse watering daily as seedling trays dry out quickly. Your little seedlings will be up in a few days.
soil mix used is pretty simple, 3 parts Bunnings native potting mix to 1 part river sand, with a handful of soil from the base of one of your local acacias as a rhizobia inoculant mixed in to every seedling tray.
They take a couple of months to get their first adult leaves but once they do they grow fairly quickly. I also then start fertilising them with swift grow (swiftgrow.com.au) every couple of weeks.