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Seeds of success

Growing from seed is akin to creating a new life and is a cheap way to expand the number of plants in your garden.

Thankfully, many Australian natives are easy to grow from seed, though some will need pre-treatments to germinate.

Many natives have developed seed dormancy as a survival mechanism and it may be necessary to break the dormancy for successful germination. Many of the hard-coated species will need some treatment before sowing. Some of them explode their seeds out away from the parent plant. This is where old stockings come in handy.

One of the most common methods is to soak seeds in hot water or scarify the outer casing so that water can penetrate the seed embryo. The development in smoke-water pre-treatment has made many harder-to-germinate species now worth a try. Soak the seed in smoke-water or water the seed trays with smoke-water.

It is vital to dry any seed before sowing; if the seed is moist it may rot in the ground. Lay soaked seeds on a paper towel in the sun to dry completely.

Species such as banksia, eucalyptus and hakea are encased inside a hard fruit and won’t release the seed until after picking. A great way to get them to open is to place the whole fruit inside a paper bag and leave it on the dashboard of your car for a few hours on a hot day. The capsules will open and release the seeds inside.

Callistemons, melaleucas, eucalyptus, hakeas, banksias, calothamnus, tea-tree, kunzia and acacias can all be successfully propagated by seed. The best seed is found in the oldest unopened seed cases in the oldest wood. Mature seed is not found in cases that are green — they must be brown or grey. Prune off the branches and place immediately in a paper bag. Always label the bag.

The growing medium for seed sowing needs to be very porous but able to retain moisture. Seed-raising mix is ideal — it is a combination of fine sand and potting mix with added vermiculite. This allows the small roots to penetrate through the mix.


Acacia

To extract the seed dry, shake and sieve, then pour boiling water over and soak overnight, or you can sandpaper the edge of the seed coat, being careful not to damage the embryo. Seeds will store for up to 50 years and germinate in 2-7 days.


Kennedia

Collect the dry pods and shake to release the seeds inside. Pour hot water over and soak overnight. They will germinate in 3-15 days and can be stored for up to 50 years.


Hakea

Pick when mature and place in paper bag. Seeds should release in 2-3 weeks, if not put in the oven for half an hour or on your dashboard. Nick the hard outer coat or place in boiling water. Use freshly extracted seed, but do not sow during high humidity. Germination is 2-5 weeks.


Banksia

Lightly cook in the oven at 100C for an hour or place on your car dashboard to split open the follicles. Use tweezers to remove the thin black seed inside the capsule. Bankias are a bit susceptible to damping off so make sure there is plenty of ventilation and the seed is dry when planting out. Germination takes 2-6 weeks.


Grevillea

Put mature pods in a paper bag or place stocking over nearly mature seeds as they explode on opening. You can either soak the seed in boiling water or nick the outer seed coat. Use the seed within six months. Germination is 1-8 weeks.


Eucalyptus

Select seed cases at least 12 months old. Shake and tap seed out fully as the fertile seed is at the bottom. All eucalypts have a lot of packing which often makes up 80 per cent of content. The actual seed will be dark brown/black. The dashboard trick works well, or leave them in a paper bag in a hot spot. Store seeds up to 11 years. Germination occurs in 7-14 days.


Leptospermum

Place in a paper bag or stocking over the fruits until capsules split open. No pre-treatment is necessary. Seeds store up to 20 years. Germination is up to 21 days.


Kunzea

Cover fruits with a cloth bag or a stocking as they release their seed on the shrub. Soak in hot water overnight. Germination is 5-14 days and seeds can remain viable for up to 10 years.


Anigozanthus

Pick flower as colour fades and is dry. Place upside down in a paper bag in the sun, then crack capsules with a rolling pin — there will be about three seeds per capsule. Use fresh seed and allow 21 days for germination.


Helichrysum (everlastings)

Collect when the flower centre loosens and store in a glass jar or paper bag. Sow the seed directly into the ground. Germination takes anything from three days to three weeks. Snails love the little seedlings, so keep some beer traps around the area.