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I covered the question of growing plants from seed or cuttings in another blog. Now I’d like to explain a little more about how to grow plants from seed.

Germinating seed can be as simple as scattering some seed on the ground or in a pot and Voila! It all happens. But often its not that easy and in fact can be down right frustrating. Why?

Well there’s a whole heap of factors that affect seed germination. If you’re buying packaged, branded seed such as vegetable seed then you can be fairly sure the seed will germinate provided its not out of date and you haven’t killed it! You see seed doesn’t last forever – although some lasts for many years, some species need to be germinated within about 12 months of being harvested because viability drops off really quickly (viability means it is capable of germinating ie the embryo in the seed is still alive).

Seed storage
For most seed of most European varieties, keeping the seed in the fridge is a good idea but recent research with many Western Australian species has shown they need to go through a process called after-ripening and that means room temperature storage is best. And when you think about it, Western Australian species are not used to going through a period of winter chilling so that sort of makes sense.

Other requirements and treatments
Some species require light for germination and so you should not cover the seed while it is germinating. This includes species such as lettuce and many other small seeds. Many hard coated seeds such as Acacias need to be scarified in some way – dropping them in boiling water is the easiest way but sandpaper can also be used. For larger seeds nick the seed coat to allow moisture in. Some seed contains inhibitors in the seed coat that have to be leached out. That can be done under running water. Nature does it over winter in the rain. Often seed may be dropped in acid to help it germinate – this is just another form of scarification. As is passing through the digestive tract of an emu, bird or other animal!

There are also a number of other specific chemical treatments that may be used on seed. For example priming seed with potassium nitrate often helps germination. Sometimes hormones can be used (gibberellic acid for example). If you have collected the seed yourself then there are a number of other considerations. Was the seed harvested at the correct stage of ripening? Is the seed even viable ie does it have an embryo and is that embryo mature? Many native plants have a large degree of seed predation – insects may bore into the seed and eat part of the inside. Most of this can be answered by cutting the seed open and examining it under a magnifying glass.

If you’re a native plant lover then you’ve probably heard of smoke treatment. There are certain compounds in smoke that help trigger germination in native plants. Extensive work has been done on that at Kings Park in Western Australia and also in South Africa. Both these places have plants that have evolved in an environment prone to bushfires.

If you’re having trouble germinating something, here are some references for you. And always try a search on the internet for your species, you may be surprised at the amount of research work out there that has been done.

http://www.backyardgardener.com/tm1.html

Australian seeds: a guide to their collection, identification and biology By Luke Sweedman, David Merritt, Kings Park and Botanic Gardens, 2006 CSIRO Publishing

Ball Culture Guide: The Encyclopedia Of Seed Germination by Jim Nau, 1999, Ball Publishing.

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So many times this comes up in conversation. Saving seed of something to grow. And how often it is a waste of time! For a start so many plants grown from seed will not resemble their parent. This goes for almost all fruit trees and all roses for starters. Anything you buy with a name like Babyface, Gala, Red Globe, Hickson, Black Beauty etc will be a cultivar and unless you grow it vegetatively from a cutting it won’t be anything like the original. Even if you can grow it from a cutting its still not that easy. Apart from Plant Breeders Rights legislation which means its illegal to propagate, there is about a 99% chance it is grafted onto a rootstock that also gives the scion (what’s on top) special characteristics. Often resistance to a particular disease but it may make it more compact or more vigorous for example. Many conifers are selected cultivars grafted onto a rootstock.

Most ornamentals you buy from the nursery are vegetatively propagated. So camellias, grevilleas, lavenders, you name it, they are all grown from cuttings.

Another advantage of growing from cuttings is that the material is usually adult. That means it will flower or fruit almost immediately. Plants grown from seed often take years to flower or fruit. That mean 5-6 years to find out that lovely pink tree you took the seed from is now white! The exception to this is some plants that have juvenile leaves – like some eucalyptus species. You can get cuttings of juvenile material to strike but the resulting plant will still be juvenile and will take some time to flower.

Of course there are some plants that are relatively true from seed and some that can’t be grown from cuttings so seed is the only way. Most banksias, dryandras (OK these are now renamed banksias but you know what I mean), hakeas and acacias are like that.

Some other plants are usually grown by other means, such as dividing them up or tissue culture. Most ferns you buy are tissue cultured, some are grown from spores. Many house plants are tissue cultured, also orchids. Kangaroo paws are mostly tissue cultured, a few are still grown from seed and division is possible but too slow for commercial use.

There are some differences in structure between seed and cutting grown plants. Most seedlings have taproots that head straight down for the water table, they aren’t present in cutting grown plants, though over time some roots may take over, become dominant and head downwards to a source of water. But in any case, in most plants, seed or cutting grown, 85% of the roots that take up water and nutrients are in the top 30 cm regardless. In proteaceous plants eg banksias, the specialised proteoid roots form when its wet (so usually winter unless you are irrigating) and they can be extremely shallow – that means don’t cultivate or spray herbicide around the plant if you want to be safe.

By the way – we pretty much hit 10 mm/day evaporation on those last two hot days. I hope you took account of that in your irrigation. My citrus are sizing up and I made very sure to give them two drinks on those days.

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I promised I’d start getting some of my pics up on the web so here they are

I haven’t finished adding or labelling yet so please bear with me.

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Since I’ve professed a love of our endemic flora I think its about time I talked about some of them! We have quite a big garden and it has a wide range of native plants in it from all over Australia. I have a particular fondness for grevilleas, hakeas, banksias and verticordias. Since I haven’t been that diligent in uploading all my flower photos so I will direct you to my partner’s picasa gallery where you can view heaps of Banksias, quite a few Hakeas and miscellaneous other species from our block. I haven’t got around to compiling all my verticordia pics but when I do I”ll let you know. So anyway you can go there and have a browse.

Banksias do really well at our place and we have quite a range of them. They do really well at our place. I guess my favourite is one from Albany way – B. cuneata, the matchstick banskia. It has the tiniest flowers of bright pink and lime green and doesn’t really look like a banksia. Just beautiful! It has a rellie up this way –B. ilicifolia. Not common in nurseries, we got it from the Banksia Farm in Mt Barker – well worth a visit if you’re down that way and they sell plants and seed as well. They also have a lot of dryandras (now also banksias thanks to molecular taxonomy but not accepted by everyone). Dryandras don’t get much publicity but they are also amazing plants – some of them have the most incredible foliage and their form is so architectural – well under utilised in my book. OK, I’ll get some of my dryandra pics up too! Ones like Dryandra drummondi and D. folisissima (well OK, B. drummondi and B. foliosissima). Also not common in nurseries and guess where I got mine – The Banksia Farm.

One of the really spectacular grevilleas that’s now relatively mainstream in nurseries is G. petrophiloides. I have about 5 of them and one especially has just taken off like a rocket. It obviously likes the clay we have in our soil. I’ve also been lucky enough to get some Grevillea scapigera which is a really critically endangered grevillea from Corrigin which is a groundcover with the most gorgeous creamy white flowers held aloft above the foliage.

The Australian Native Plants Society has quite a lot of pics on their website if you want to see more species and there are a number of study groups which specialise in various genera. I belong to the grevillea group which has a website on yahoo groups, also with lots of piccies.

We have plants in flower all year round. For example at the moment there’s Eucalyptus caesia and Hakea laurina out, also Hypocalymma xanthopetallum, Thryptomene baeckaceae and Eucalyptus woodwardii to name a few. And the birds love them all! We have heaps of birds come round, even a pair of rainbow bee eaters. The black cockies love our pine tree and the jarrahs and sit up in them and totally vandalise them. We often end up with about a foot of euc sprigs under the trees and pine cones all over the driveway!

OK I’d better go and upload a few photos so you can see more of what I’m talking about. I’ll come back later and let you know where they are.

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