Dense shrubs needed - any ideas?

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Shirley Hardy
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Dense shrubs needed - any ideas?

The least of my problems is an insect invasion in the garden or a drought. My main problem is getting certain plants to acclimatise to the frosts here. Frosts occur in Tenterfield, NSW, every Autumn and Spring when it is not cloudy overnight. That's 3 months of frost, 3 months of no frost, 3 months of frost, 3 months of no frost. That's the cycle and it doesn't change.

After planting a Golden Guinea Vine and a Native Frangipani two days ago yesterday morning I woke up to find those two seedlings had turned to mush along with my Daylily.

Now, here's the real problem... if my plants are up against the front of my flat in a pot (out the front) the frost doesn't affect them. The flat's wall is on the west side of the plants, to be specific. I also live in a frost hollow and it does get down to minus 10 degrees C. here in Autumn and Spring but can get that cold in Winter too. Cold enough to freeze puddles of water at least 2cm thick with ice.

I'm trying to plant things out in the open basically that's exposed to the elements. About 99% of my natives are laughing at the frosts and thrive in this frosty area. But I'm trying to grow more delicate, frost tender plants in my garden as well. 

After yesterday I now have to redesign my garden for the frost tender plants and hope they'll adapt to the frosts. In order to do this I need to plant dense growing shrubs on the west side of those plants to shelter them from the frosts until they've established themselves. 

I'm after dense growing shrubs that trees can grow through, that will be about 4-5 feet tall and about 3 feet deep maximum - any width is okay. I'd prefer a native or indigenous species to my area. I'm also after shrubs that are dense but upright that will also form an arching canopy no taller than 5-6 feet tall. I'm after any native plant that isn't a grevillea, as there's already too many grevilleas on this property and I'm confined to a narrow garden bed space of about 20-30 feet long by 4 feet deep/wide on average.

I'm currently using pulled up weeds and potted plants to form a frost shelter for my frost tender plants as I planted 3 more Native Frangipanis in the front garden yesterday. 

Any plant suggestions are greatly appreciated. 

Shirley Hardy
Shirley Hardy's picture

Yeah, I have an idea..... plant shrubs closer together to create dense shrubbery.

I'm at Tenterfield, NSW. (Formerly known as "Hyperbirds".)

Woko
Woko's picture

Species indigenous to your area will tolerate frosts, Shirley.

Shirley Hardy
Shirley Hardy's picture

That's not always the case, Woko. I have an indigenous Fringed Wattle and even though it is fast growing it is not frost tolerant at all. It is over 5 feet tall and in Tenterfield we get consistent frosts throughout Autumn and Spring. The Fringed Wattle gets frost burn even at 5 feet tall. It is doing better this year with only minimal leaf tip frost burn. It is approximately 2 years old. Next Autumn/Winter will show considerable more adaptation of the plant to endure frosts and maybe then it might be frost tolerant. I almost lost it during it's first 12 months in the ground but it adapted quickly the next year.

Woko, it is simply not that easy. It sounds easy enough to go and buy indigenous plants and plant them in the ground. As I've mentioned before in various other posts, locating indigenous plants locally is next to impossible as most of the ones I want to grow are not available locally. I do plant shopping online but it takes me months of searching to find what is indigenous to the area. All of my plants were seedlings when I bought them. It doesn't matter where they come from - its a matter of will they adapt and survive. 

Tenterfield gets extreme weather, from minus 10 (it's actually minus 14 and getting closer to minus 20) degrees Celcius and up to 55 degrees Celcius in Summer. Ground temperatures are sometimes above 60 degrees Celcius in Summer. The seasons used to be consistent. Now they are just erratic and unpredictable. Autumn seems to be getting shorter, and Summer, longer. Tenterfield just went through an 8 month Summer season, a 3 week Autumn season, now its Winter. Each passing year is even more difficult for plants to survive here, indigenous or otherwise unless they have already adapted and are already established and can deal with drought, frosts, more drought and more frosts and extreme weather conditions.

Because of the weather conditions during these passed 2 years I have decided to change the type of plants that are more adaptive to these weather conditions, and grow them instead. Well, at least as the basic foundation plants for the garden anyway. Growing more Callistemons is my first agenda. They are not shrubs but when growing their ability to adapt also somehow helps neighbouring plants to adapt and survive. I was thinking of growing more grevilleas but they are not adapting to the new climate conditions anymore. I keep losing new grevilleas I plant in the garden. 

If I want plants to survive in the garden now they have to be as tough as anything and have narrower leaves. Broad leaved plants struggle to survive in the garden which is why the Fringed Wattle is actually adapting better than the broad leaved wattle tree. I bet that if I bought a Woolemi Pine it would survive and grow in the garden as it is a narrow leaved plant and snow/frost tolerant. It'd cause havoc to the Flat's foundations over time which is why I don't get one. 

I'm at Tenterfield, NSW. (Formerly known as "Hyperbirds".)

Woko
Woko's picture

I'm surprised to read that Fringed Wattle Acacia fimbriata which, I believe, is indigenous to your neck of the woods, is frost intolerant. I checked Florabank (https://www.florabank.org.au/lucid/key/Species%20Navigator/Media/Html/Acacia_fimbriata.htm) & read "tolerates frosts in the 0 deg to -5 deg C  range or tolerates heavy frosts colder than -5 deg C". I take it that you're confident that the Acacia which is suffering frost burn is in fact Fringed Wattle. The fact that it's a young plant may well have something to do with its frost intolerance, as you imply.

Yes, it's frustrating if you can't find nurseries stocking indigenous plants in your area. Sometimes a long term approach needs to be taken. E.g., regularly & frequently visit nurseries & ask if they stock species indigenous to your area. Create a demand. I remember when I used to frequently fly to Whyalla on planes which allowed smoking. I persistently requested a non smoking seat even tho' I knew the airline, in its wisdom of the time, had none. Persistence paid off because, even tho' my requests were made at a time when smoking was an encouraged part of our culture, eventually there were non smoking seats designated on their Whyalla flights. And even more eventually all seats were non smoking. Ah, sweet breath of life!

Shirley, I think you're right about the narrow-leaved plants, particularly those that are hard of texture, surviving drought & heat better than broader-leaved plants. But I'm not sure about the Wollemi Pine surviving in Tenterfield. The fact that the Wollemi Pine is located in a very restricted area of Australia suggests its requirements are very specific or it is a botanically ancient plant hanging on in the one location. Having said that I notice the species is readily available in some nurseries. It's probably trendy to have one in some quarters. But caveat emptor, I suggest.

Shirley Hardy
Shirley Hardy's picture

Woko, thanks for your comment. Yes, I do have a Fringed Wattle. I bought it from allnatives, and bought it as a seedling online. I buy plants regularly from that website. 

Did you know that every single seed, from every plant species, starts from scratch. Every single seed of a plant, when it germinates, has to adapt to it's environment the moment it germinates. With the genetic blueprint of it's parents it has to adapt and change right from the moment it is born. If it doesn't it will die. In order to adapt it pulls from it's genetic makeup genes which contribute to surviving frosts, for example, and will modify those genes to not only survive but be even stronger and healthier than it's parents. Plants are phenomenal creatures with more genes than us mammals, and as such, can adapt. The plants that die are the ones that do not have enough genes to adapt and modify their own genes. Its fascinating.

So on that note, my fridged wattle is adapting but at the same time it is changing it's genetic makeup and coming up with new and improved genes just to protect itself from frosts and extreme heat as I write this. I bet you can't do that? I can't do that. It has all been proven by science to be the case that plants do this.

On a further note, there are a lot of people out there, mostly overseas though, who have successfully grown Woolemi Pines (bought from Australia as cloned plants) and these trees are adapting to extreme weather conditions. I'm talking about growing in 6 feet of snow and hotter and drier weather or moister weather than we get here in Australia. Woolemi Pines are snow and frost tolerant and protect themselves with cone structures over their leaf tips prior to winter setting in. They are drought resistent. However, the common theme I've read about why these trees die is because they are "smothered with too much love/attention from humans". 

The thing I have learnt about plants is they need to be put in the ground somewhere, and whatever soil conditions they are growing in at that moment, leave it like that for the first 12 months to 2 years. Only after that slowly begin adding bits of organic matter to introduce nutrients for the plants. If you don't do this plants will not be able to adapt, as they cannot adapt quickly enough to the constant soil changes or changes in climatic conditions. And all plants need sunlight and be in their environment else they will go deaf and stress out. Plants can go deaf and it has been proven too by science.

The only thing with Woolemi Pines is they need a specific mineral to help them grow (forgotten what people were adding to their pots) and they don't like scorching heat when they are young. Intense heat will kill them when they are young but after they have adapted they start growing rapidly at a rate of about 3 feet a year I think it is. Oh, and the cloned seedlings do eventually start growing their own cones and can self seed. If left to their own devices to revegetate, the self seeded seedlings are about a 50% percentage rate. 50% of the seeds germinate in one given spring/summer season. 

The potential to repopulate our own Woolemi Pine populations is enormous, especially if we can get seeds from the overseas plants that have more genetic diversity and have adapted to harsher conditions than here in Australia. And that is how you increase genetic diversity within the species. You grow them elsewhere, grab the seeds, and grow the seeds elsewhere. You keep mixing up the genetic pool with fresh seeds from elsewhere until there is a lot of different plants, grown from seeds, that grew in different climatic conditions. The trees will then crossbreed with each other and, voila, even more genetic diversity, and we have Woolemi Pines that are capable of adapting to every climatic condition on Earth. Its simple logic really.

Adding to this is you do not grow sibling plants, or plants growing together when young, near each other. The plants will consider these other plants as siblings and as such will not reproduce with them. Intentionally introducing non-relative seedlings into, for example a stand of mallee of the same species, will actually increase genetic diversity within the stand as well as new mates to breed with. I believe this is the main problem with our own native plants across Australia - there's not enough genetic diversity within each species as they're all basically related to each other. As a result dieoffs happen because there is no new genetic dna to help them adapt and survive even further. Think of it as humans breeding - no new non-related humans to breed with so they are forced to breed with their daughters, sisters, aunties, etc. The genetic dna weakens as a result and everyone becomes genetically weaker because of it. Everyone gets sick and dies because their offspring are too weak to adapt to anything. That's what its like for plants too. They need "fresh blood", so to speak.

GENETIC DIVERSITY IS CRITICAL FOR THE SURVIVAL OF EVERY PLANT SPECIES ON EARTH.

I'm at Tenterfield, NSW. (Formerly known as "Hyperbirds".)

Woko
Woko's picture

You're spot on about genetic diversity, Shirley. When doing ecological restoration work where there is hardly any natural bushland or forest remaining it becomes a huge issue. I've made this an priority in my own work by trying to obtain seed from a variety of sources. The importance of obtaining plants which are strong in their genetics & can survive harsh conditions highlights the foolishness of large scale land clearance which is still occuring in Australia.

Shirley Hardy
Shirley Hardy's picture

Woko, I'm really glad to hear that you can do ecological restoration as you call it on your property. It is nice to be able to do that and sit back and enjoy all the benefits and beauty of it all. However, in my environment that is not so easy as it sounds. Nature itself is working against me. Rainfall? What rainfall? Oh, that flock of birds flew overhead again and had a crap in midair enmasse. That's what its like or that annoying mist rain that barely gets the grass wet. If we're lucky we might get 2-5 decent downpours of rain per year - I'm not kidding either. 

Large scaled land clearance is what is happening outside of Tenterfield, just 10kms south of here, displacing bird species. Hence the recent sightings of 2 new species this year. As the weather continues to heat up bird families and whole communities of birds are relocating themselves elsewhere. Its really sad because I'm noticing a drop in resident bird numbers of Australian Magpies, Torresian Crows, Masked Lapwings, Crested Pigeons, and the smaller little native birds. Numbers do drop in winter but the continuous lack of rainfall seems to be making resident birds just up and leave. At the rate things are going it won't matter if I grow a garden or not because there may not be any birds around to enjoy my garden. Any plants that do survive and flourish will more than likely have to find new pollinators and predators. My plants might have to change to attract other bird species, like Sulphur-crested Cockatoos, Galahs, Little Corellas and those very fast flying, small parrots that come to town to roost every summer/autumn that I can never take photos of nor identify. Their numbers were down by probably 100 last year. They roost in the exact same trees every year but sometimes it varies. They sometimes spook easily. Sulphur-crested Cockatoos are quiet in comparison to these little parrots.

My previous comment really makes me think about things here - about plants. Genetic diversity is a good thing for plants - for all life forms actually, but when plants struggle to adapt to an ever changing "weather patter/condition" it makes me wonder whether plants can adapt quick enough to it all. Only the strongest will survive. In the plant world I think it is only the ones with the most dna are able to adapt to the constant changes and therefore can survive and flourish. All else will die. This makes me wonder whether gum trees are adaptable enough to endure desert like conditions as that is what Tenterfield's weather is starting to feel like it is becoming. Either that or South Australian weather.

I'm at Tenterfield, NSW. (Formerly known as "Hyperbirds".)

Woko
Woko's picture

Extended dry periods are not good times for planting. Patience is needed to await the next good rains which normally fall in Tenterfield summers as I think you've said before, Shirley. With an average rainfall of over 800 mm per year I would expect a reversion to more normal rains, if not above average conditions, within your life time, notwithstanding the effects of climate change. Mind you, as an economist once said, many a statistician has been drowned crossing a river marked AVERAGE DEPTH FOUR FEET. 

Shirley Hardy
Shirley Hardy's picture

Rainfall is not 800mm per year anymore, Woko. It used to be but its not now, unless it all falls during the heavy rainfall we get several times a year. I remember being told by a local when I first moved to Tenterfield back in 1994/5 that I'd brought the rain with me and the drought had broken. So obviously "droughts" are normal here with it being broken into wet cycles that could last for years, then the drought conditions set in again for even longer periods of time. 

Keeping that in mind, Woko, planting anything has to occur during the frost seasons and before the summer heat sets in. The climate has been changing in town for the last 5 years to hotter, drier conditions. Plants getting frost burn is inevitable but planting them initially is tricky business because it has to be timed perfectly so the frost doesn't kill them before the spring frosts arrive. If plants make it through to their first year in the ground and show signs of health and adaption they will make it and will survive. But plants have to be very adaptable and tolerant of heavy frosts, extended periods of intense heat, minus 15 degrees Celcius and a various combination of weather conditions. Summer heat can disappear overnight without warning and the seasons can and do change rapidly - within a matter of days without warning. An Antartic cold weather front coming through can and does change Summer to Autumn, believe it or not. Birds are forever changing their breeding times (that breed once a year) to match the cooler and wetter conditions, despite it being out of season for them to breed. Plants take longer, especially the decidious trees around here, to adapt to the sudden change of seasons but they sense when warmer nights are here and begin to turn green again. Day temperatures are getting hotter and night time temperatures are getting colder for longer periods of time. No two years are exactly the same when it comes to the weather and seasons but there does seem to be a pattern forming.

Rain is infrequent and unpredictable but is lasting long enough to soak deep into the ground. Maybe not on the first day but on the second or third day it does. Flooding doesn't happen anymore as there's just not enough heavy rain to flood the creek.

The thing is, Woko, I don't know what normal weather is like here. I haven't lived here all my life but from the look of things I'd say drought is the normal weather conditions for Tenterfield with some rain here or there. 

I feel that the best time to plant anything is at the very end of Autumn, watered once then left to their own devices. The first sign of a slight change in leaf colour (after being frost burnt) or flower growth is when I begin watering the plants again, less in winter and more in spring and summer until they are established (or 3 years old). New plants should only be added once a year, not as I had been doing it. I was also watering the plants too much and often disturbing their roots but uprooting other nearby plants. 

Some good news: It started raining yesterday and is raining again today for the first time in many weeks.

I'm at Tenterfield, NSW. (Formerly known as "Hyperbirds".)

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