Burnley Gardens: Your Hidden Resource

Take a journey through the historic Burnley Gardens with three Alumni and staff members, Sascha Andrusiak,  Dr Chris Williams and Andrew Smith.

Discover our urban food jungle and some of Chris’ novel crops, learn tips on keeping your garden healthy in winter and beyond, and come behind the scenes with us as we take you through the nursery and greenhouses!

Then read the supplementary Q+A, where our experts answer audience questions.

Journey through Burnley Gardens

Your gardening questions answered

Indoor planting

Q: How do I care for indoor plants?

Sascha Andrusiak: Over-watering is the biggest problem that we have. Water once a week in the sink and put it back.

Q: How can I increase the success of my propagation of indoor plants at home? What do I use to plant my cuttings into?

SA: When you're propagating indoors, you can use a variety of methods. Cuttings are your primary method. Some people can just get away with popping a cutting in a glass of water and popping it on the windowsill and it will form roots that way.

You can then very carefully transition it from water into a potting mix. Always go for a good quality Australian standard potting mix that you buy that has a complete fertilizer in that mix. It's more expensive, but it's worth it in the long run because it is to the Australian standards, therefore its airfield porosity, its fertilizer levels and its makeup is suitable and prime to grow what you want to grow and you'll get the best results.

Some of the cheaper mixes are made from questionable components, which may have inappropriate pHs and AFPs, and that's where a lot of people fail with their attempts because they find a medium that doesn't really support that plant.

You can grow indoor plants in water for several years. I have a Philodendron cordatum that's been sitting in a red glass vase for about six years. I haven't fed it, and it hasn't grown very much, but it certainly hasn't died. Plants are pretty resilient like that.

The other way you can propagate your indoor plants is by division, and you can look that up on the internet. Some plants like spathiphyllum, peace lilies, or sansevieria, you can actually take them out of their pot and just break the clump apart very carefully and re-plant that again into good quality potting mix. That's a really good way to bulk up your supply.

And then you can do things like leaf cuttings. You can actually take individual leaves of species like saintpaulia, so African violets, begonias, peperomias, sansevieria, and you can pop them into some potting mix again, probably about a centimeter deep, water it in, pop it on the window sill, and you will probably be able to come away from that with new plants.

It’s a really lovely process to watch as well. You don't need a glasshouse to propagate some of these indoor plants.

Pots and small gardens

Q: I live in a rental with poor soil and little garden space. What are the best veggies for large pots, especially leafy greens?

Chris Williams: Before we even talk about the plants, the key recommendation is to make sure you use good quality potting mix. So don't dig your garden soil and stick that into the pot. Splash out, don't buy the horrible cheap staff, the $3 bags from the supermarket. Get the better stuff from the big green temple (which is Bunnings, of course).

It's the quality of the mix, making sure that the pot is big enough and just care and attention to the crop. Don't let them dry out when they're in pots. I find the rookie mistakes are planting vegetables in with too little light, so poor aspect, so that they're shaded, and not taking soil moisture seriously.

There’s so many so-called ornamental plants, native or exotic, that don't actually need to be mollycoddled, even in a hot summer, depending on how established they are. But vegetables and fruit trees are about yield, so you need to understand how much watering they need.

And then grow things that are relatively easy, like silver beet, brassicas like broccoli. Definitely lettuce. I've seen people grow quite good carrot crops in pots, too.

Potatoes do well. If you're a beginner, potato is a really good starter crop, because if you're buying a seed potato, so you’re getting a virus free potato tuber from a nursery, and if you put that into a relatively large pot at the right spacings, they’ll just boom ahead. It’s really satisfying pulling fresh potatoes out of the ground or a pot.

Sometimes you can have success with tomatoes, but Andrew and I were actually discussing this morning what a nightmare crop they are, especially for a beginner, because they’re so disease prone.

Q: How do you keep your soil fertile in pots or large planters so that you can continue to grow food crops year after year?

SA: If you're talking about a small pot, something you can hold in your hands and pick up, then I would be replacing that potting mix each year, each time you plant a new crop.

If you're talking about a raised vegetable patch, then you would be topping up and incorporating organic matter every time you clear that bed out.

And you'd also feed. How heavily you feed will depend on the crop. You'll be feeding as your crops are growing as well. Not too much. You don't want to go overboard. But for example, leafy greens require a lot more food. Tomatoes will have a little bit less than leafy greens.

And then with your root crops, you can bring down the nitrogen a little bit, because if you put too much nitrogen on root crops, you'll get a lot of leaf and very little storage. So it depends.

But definitely you're looking at replacing the soil in your pots, because the previous crop will have taken out the nutrients and the potting mix will break down and become less suitable for optimal growth.

And your raised gardens, you want to be incorporating more organic matter, because you'll notice over a year or so, you'll see the level of sink down. And so when you take that crop out, get your garden tools out and mix in some organic manures, then give the bed a couple of weeks to settle down again, and then you can start planting

CW: One thing we don't talk about enough is that pots, even with good quality potting mix, if they're outdoors, particularly if they're sitting on soil, will be invaded by earth worms. And people forget this: worms eat stuff. They eat potting mix. It goes through their system. So that breaks down the potting mix into finer particles. And that's part of the decomposition process, which makes potting mix sink so dramatically in outdoor situations. As it gets finer, as it passes through the worm’s gut, it collapses and becomes waterlogged. So just keep an eye on that one. That’s why in nurseries they're always trying to keep worms out, believe it or not.

And the second thing is just to realize that a black pot sitting in the sun in late spring through summer is getting baked. So sometimes the reasons that things in pots don't do so well, or even galvanized iron raised beds, is because the roots are getting absolutely cooked compared to what would be happening if they were growing in the ground.

Q: Can you have a fig tree in a small, western facing yard?

AS: They’re long lived, so whatever you put in, you're going to have to maintain into the future. As far as I know, there's no dwarf fig tree, so you're looking at something that’s potentially, fully grown, five metres by five metres. You could probably maintain it to three by three.

But certainly the Western sun, no problem. When you think about where figs grow, Greece, the Middle East, they'll take it hot and tough.

CW: I think Daleys in Northern New South Wales occasionally do grow a dwarf fig variety. But you can prune them harder.

Edible gardens questions

Q: What's the name of the plant that looked like paw paw [in the video]?

CW: That’s babaco. It’s a hybrid. One of its parents is mountain paw paw, which is also edible.

Q: Are the native citrus you mentioned edible?

CW: Absolutely. The native citrus are, I believe, all edible, and there's about three of them available from nurseries. One of them is the famous finger lime, which is naturally very variable in its population, so you get purple ones and ones that are yellow flesh and green. They’re now internationally famous and fashionable, and relatively well available. The desert lime is around a bit too, which is a rounder, smaller fruit.

Q: What soil type and water needs does taro have?

CW: It’s pretty good in all soils. It does like a very moist soil though, so it's actually pretty ideal in a clay soil. However, I've grown it in a sandy soil as well, and as long as you keep the water up, it's fine.

So I'd say unfussy about soil type, but definitely at the higher end of water use. Some people will tell you that it needs almost to be flood irrigated, which is how they grow it famously in Hawaii. But that's not true. In my experience, with the right varieties, just treat it like a standard summer vegetable. Definitely don't let it dry out, but it doesn't need to be watered in excess of a tomato plant.

Q: Where can you purchase taro to grow?

CW: Generally speaking, if you want to buy official varieties, you have to buy them from online nurseries. As far as I'm aware, there aren’t any nurseries in Melbourne that sell edible taro.

I've got a collection of about six different varieties now, and they come from an online nursery in Queensland called Green Harvest, who sell a whole range of unusual edibles. But quite a few of them, I actually got from buying them at markets. I could recognize the corms, which is the tuber. Diggers sell a purple one.

Sometimes I provide plants for the Friends of Burnley Gardens when they have plant sales, and I do sell taro through them. So perhaps post-pandemic, if we have a sale in the future, they’ll be available from plant sales here at the Burnley campus from the Friends of Burnley Gardens.

Q: If the temperature is too low, will the taro crops die off?

CW: I've grown taro in the field station where we do get frosts, and it's not a scientific trial, but it's certainly a lot of evidence. What I’ve found is you see that the taro plants grow extremely well during summer to about late autumn. You get decent yields. And then they suffer from frost during winter, they collapse, but they come back strongly. That's the real test. Maybe you won't grow taro that well in cold stream, but even then you probably would get a decent crops.

The thing is, it's a food crop. If it looks dreadful during winter, you can still harvest it. It will come back strongly in spring.

Q: How can you tell the difference between edible and non-edible elephant ear plants?

CW: You do need to be careful. The standard elephant ear that people talk about in Melbourne is alocasia, commonly used as an indoor plant. You technically can eat that, but in Polynesia and Melanesia it's used more like a survival food. You've got to cook it for hours to make sure that the calcium oxalate crystals inside the tuber have been eradicated. That applies to normal taro too, but it's not nearly as bad. Look it up on the internet just to make sure that you get the right ID.

Q: What can you do about oranges with thick skins?

CW: If you’re used to the paper thin skin of a commercial orange, then you will find the Melbourne grown one slightly thicker because of the cold. As long as you've got plenty of the fruit inside, it shouldn't be a problem, but make sure you do irrigate citrus properly. So water them over summer and the skin shouldn't be as thick.

Q: What causes small buds on Brussels sprouts?

CW: They’re a winter loving brassica, so I think it's an input thing, meaning you just need more compost and more manure. Make sure it's in as sunny a position as possible. They’re quite heavy feeders, cabbages, broccoli, Brussels sprouts. They like neutral to slightly alkaline soil, so make sure your soil is not too acid.

Q: What should you do after digging out a patch of agapanthus?

CW: First of all, I'm not a complete agapanthus hater, but they're pretty overwhelming and there's probably way too many of them in this city.

I think if you've had to dig them out, make sure that you go over that area. If it's a whole vegetable patch, I think raising the area for vegetable production is good. It doesn't have to have retaining walls, it just has to be extra soil you add from your pathway.

Really get that prepared for spring and add compost, even if it has to be commercial compost initially, manure if you can get your hands on it, and I’d definitely do a pH test too, just to see what your soil is: acid or alkaline. If it's around 6.57, you don't have to really do anything to that. Go for it.

Q: What’s the difference between winter and summer pruning?

Andrew Smith: With fruit trees, the difference between the winter and the summer is that the winter pruning causes a lot of stimulus, a lot of growth. You will end up with an explosion of growth by doing these big heavy cuts or any sort of pruning. Summer pruning actually has more of a dampening effect.

Q: I've planted two feijoas. When and how should I prune?

CW: You can prune them quite hard. Karen Sutherland from Edible Eden Design actually hedges them and they still flower on the inside and fruit. They're really plastic or pliable in that way. You don't have to prune them at all. You can just let them form into a big bush. Or you can prune them to fit a garden bed.

The only pruning I'm going to do this year on a big specimen we have in the field station is to uplift: remove the vegetation from the first 50 centimeters of the trunk, from the soil up, just so that next year, when it fruits, we can get in underneath and pick the fruit as it falls to the ground.

SA: The fruit is just absolutely beautiful. Really, they produce so much fruit. I never had any idea that they were so good. I just haven't paid attention. I think so many people focus on your traditional crops, and just haven't paid attention to all these other wonderful fruit crops that are around.

Q: I have several cool climate bananas planted into my backyard food forest. One has sent out new plant shoots at the base. Are these growing into productive plants, or should they be removed?

CW: By and large, they should become productive plants. The ones we have in the gardens that are very productive all came from side shoots or pups that were brought in by colleagues here.

Q: How do you know when carrots are ready to be plucked out of the soil?

CW: When you scratch around on the surface of the soil and you see that the diameter of the carrot is the size that you want it. So, you've got enough foliage and you push the soil away and you think, yep, that's the size that I want it.

Remember, too, that over winter they can stay in the soil. You don't have to harvest them in one go. If you can afford to have the space occupied, you have the carrots sitting there and just pull them out when you need them. So you're using your soil as a kind of fridge.

Once the season warms up, let's say by October, they'll start to push up this giant flower spike. Then they start getting woody, because they start drawing on the carbohydrate in the root, which is what the carrot is, and they’re spoilt.

Q: Are heat mats useful for plants that normally like warmer weather, so passion fruit or basil, particularly if they want to be kept outdoors?

SA: Heat mats are great for germinating seeds in cooler weather. So now if you have a heat mat, you can probably start doing your tomatoes and your capsicums, chilis, eggplants, all your summer crops that everyone gets so excited about. Even without one, but you’ll probably have more success, higher germination rate, with a heat mat.

I don't know about using a heat mat to actually heat, say, a passion fruit. Passion fruit doesn’t need it.

AS: I think on a large scale, you might be better trying to have some other heat sink arrangement, whether its black rocks to try to absorb some of the solar radiation and then release it.

And remember, mulch will actually promote frost, rather than the other way around. It’s not like a blanket.

SA: Looking for microclimates in your own garden is really a good strategy. So against a north facing wall, where you're going to get a bit of additional heat, can keep some of those crops that would normally be killed off by a lower temperature alive for a bit longer. That's what I've found in my garden anyway.

CW: This is where gardening is about long-term experience and experimenting, because some things will look absolutely terrible, but will recover spectacularly after winter. So it's a question of holding your nerve. When your passion fruit goes yellow, or even your citrus go yellow in winter, there's no point warming. It’s a high energy cost. Unless you want to build a giant temperature control greenhouse, just know that a lot of things will recover in spring, and then you can feed them and then you’ll have six to eight months of fantastic growing.

There is actually a book out there written by an American botanist called Palms Won’t Grow Here and Other Myths. This is a guy who's been experimenting with growing bananas in parts of the United States where the temperature gets to minus 30 below in winter, and then up to 35 degrees in summer. That's the book that makes Melbourne look like Rio.

Q: What can I grow in clay soils?

AS: There was quite a good book. I don't know whether it's still in print: Grow What, Where. There was a whole section on plants for clay soil, plants for any sort of soil you could think of. That’s a really good reference, if you can get that book.

So for clay soils, it's more about anything that tolerant of water logging. And it even could be where it grows. So if it grows in a winter wet swamp of Western Australia for part of the year, well there's a good chance that it's going to tolerate a clay soil, because clay traditionally has far more water than what a lot of plants actually cope with.

SA: The traditional suggestion for a clay soil is to add organic matter, and over time, try and improve it. You can use gypsum.

AS: I know that there's lots of people that are saying this, but you try doing it yourself, ameliorating the soil. I still think you're far better off just working with what you've got.

SA: I think that’s the more contemporary wisdom with this situation, is stop trying to change things and work with what you have in the garden context when you're looking at soils. It seems to be more popular these days.

AS: If you’re that concerned, then raise the beds, have raised beds, and have the type of soil in there and deal with it that way.

The woody meadow project that the campus is involved with at the moment, they're talking about something like 15 centimeters of substrate that they’re actually just putting on the top, like a raised bed, and then they're planting into that. They're getting fantastic results just from a scoria mix, which is basically I think a nine millimeter down to about a three millimeter particle size. Of course, it doesn't have any nutrients, it doesn't have any water holding capacity, so you may need to add a bit of coconut fibre, slow release fertilizer. But all those things are a way to cope with what's above the soil, rather than having to try to change the soil that’s underneath.

CW: And I'd rather have a garden with clay soil, if it's well managed, then have a super coastal sandy soil. Because clay soil, when it's well managed, retains moisture much more than sandy soil. It has more nutrients locked into it. I had a garden on cracking clay soil, basalt soil, for a number of years. And although it was hard to work sometimes, overall, as long as I kept the moisture in, by late spring with heavy mulch, it was magnificent.

If it's really seriously compacted, it can take a while to de-compact. But organic matter and mulch is the answer. Clay soil is not your enemy.

Q: What can I do in my winter veggie patch as the weather warms up?

SA: My suggestions would be to start sewing your summer crops. That's your tomatoes, eggplants, chilies. But not into the garden, into punnets. And then you wouldn't be planting those out. You'd be growing them up, and you'd be looking at planting out in late October, early November.

CW: I'm going to use these famous heat mats here at Burnley, which is cheating I guess, to get some of these veggies growing.

Late August is a very interesting time of year because it's still cold. It's freezing today. But suddenly September comes, the days warm up. So I think planning where you are going to put the veggies is almost as important too.

SA: Improving the soil as well, for your summer crops.

CW: And if you've got any daggy leftover veggies from autumn, and old zucchinis, clean it all out, get rid of it all. Start working out where you're going to put everything.

You don't have to rush it. You’ve got October, November, even into December, to get these things in.

I'm going to be growing bitter melon for example. I’ve been converted by Vietnamese Australians to that. I love it. So I'll be growing bitter melon this year again. Good for your blood, I think.

Leafy greens, lots of cos lettuce. If you really like fresh carrots, then get that bed prepared, nicely dug so that the roots can penetrate the soil.

SA: You can put potatoes in at the moment too.

CW: Definitely, get those kipflers happening.

Indigenous plants and biodiversity

Q: What species of Indigenous bush tucker plants are success in Melbourne?

SA: My suggestion is Warrigal greens. That's a spinach-like plant and that grows really, really easily.

Yam daisies are a little bit more difficult.

CW: The interest in Indigenous agriculture has obviously been greatly spurred by Bruce Pascoe’s book, and other writers as well.

I do grow yam daisies, and to be perfectly honest with you, I haven't actually eaten any substantially yet. They’re still a bit new to me.

My main focus with Indigenous food plants are two largely arid zone Australian native sweet potatoes, that are closely related to sweet potato. I'm still in the stage of trying to see if we can get them to overwinter in Melbourne. Dr Bec Miller and I have had a student look at the physiology of these plants. They’re delicious by the way, and the tubers get gigantic.

I’m hoping in a year or two, if it’s successful, to talk to the Traditional Owners of these plants. And I know people in Central Australia and Alice Springs with Arrernte people have actually tried to look at how you commercialize one of these plants. So that's a longterm process.

But I agree, the Warragul green, so-called New Zealander spinach, is a really good one to start with. And interestingly, it has this fascinating history that it was a popular vegetable in France and the United States as early as the 1840s. And, to my absolute astonishment, when I went to Brazil a few years ago, it’s the main spinach in Brazil. And they have their own indigenous spinach, which they don't grow. Then when you tell them that what they call spinach is actually an Australian species, it obviously blows their mind as well. So it's a winner to start with.

SA: I've just had my partner bring in these Disphyma, or rounded noon-flour. And you can actually eat the leaves. They're a little bit succulent and salty.

And also Carpobrotus. I believe we can eat the fruit of the Carpobrotus, which is similar. It's a daisy, a large version of these Disphyma. So that's some other native plants that you can eat.

And of course there's a citrus australasica, the finger limes. They're just absolutely phenomenal. So introducing all this stuff into your garden, it can only do good things for you and biodiversity and our cultural heritage.

CW: The Collingwood Children’s Farm are growing a whole range of local Victorian Indigenous plants. So First Nations food crops. And they're doing that in conjunction with the Wurundjeri, who have an office at the Convent, so a close relationship. So go and visit the First Nations food garden at the Collingwood Children's Farm.

AS: As far as the Gardens themselves go, about a quarter of it would be set aside for native plants.

SA: We have a native garden that's completely dedicated.

AS: Yep. And a rainforest, a grassland, and also the rest of the gardens, right from the very start of the 1860s, they were planting Australian trees next to another exotic one. So there's an existing history of Australia natives all the way throughout the gardens.

SA: And it is a large part of our teaching in our plant identification lessons as well.

AS: Students might have to learn up to about 10 or 12 plants a week, and I don't know the proportion of native plants in that, but it would still be still be very high.

Q: What are some plants that people could plant in their garden to keep our biodiversity going?

SA: At Burnley, our different research groups look at a whole different, often native, plants. So our Green Infrastructure Research Group, Dr Nick Williams, looks at biodiversity on rooftops. So how we can actually incorporate biodiversity onto our rooftops in urban areas, and into the future, how do we keep our insects, our pollinators, happier, and keep them with us into the future. So that's one area we're working on with biodiversity and indigenous plants.

From research that I've come across and people that I've spoken to, native insects aren't necessarily just interested in native plants. So they can get food sources from introduced plants just as well as native plants, but there may be some native plants that really do rely on specific pollinators.

AS: I think also, there was a trend to have everything very neat and tidy, and I think we’ve been learning in the last decade is that it's okay to have a patch of weeds in the back corner or sticks lying around. It's about trying to have as many different habitats as you can. Not everything has to be neat and tidy and swept.

Perhaps having your own native indigenous plants that are actually in your area. There are lots of different nurseries that sell tube stock. So that's always a good place to start as far as the native plants you should use for your own environment.

But, but mixing it up and having a range of plants. And also letting them go to seed. All that helps.

CW: I think a critical thing too, and Burnley has a tradition of thinking about this, is looking at indigenous plants that are indigenous to your area. So the system we use in Victoria is classifying the whole state around ecological vegetation classes. And you can look this up and you get a species list.

But always realize you can design with indigenous plants. Ecological restoration is not incompatible with aesthetics. You can have drifts of plants and masses, or you can have them mixed like a meadow.

And maybe you have to hire a Burnley graduate to design your garden, if I could just advise that.

One of the things that's fascinating is letting vegetables go to seed. One of the things I love doing is sort of like a cheap party trick, to let a carrot flower and then get students to say what they think that is. And they normally can't imagine. You just don't think of a carrot that you buy at the supermarket or the farmer's market, what it looks like. It's a plant. It has a giant flower spike with beautiful flowers. And when you see a carrot flowering, you won't believe the diversity of invertebrates that just descend on it.

Let weeds flower to a degree. Don’t be afraid to let things flower. That's the key to preserving invertebrate biodiversity anyway, particularly insects.

Q: Where would you find information about the plants that will be unsuccessful in Melbourne in the future due to climate change?

AS: The Melbourne City Council, and one of our graduates is involved with this, went through and modelled anticipated temperatures into the future against the trees street trees that are out there at the moment. So there is some information through the Melbourne City Council. Jacaranda was a tree that came up as being something that was suitable for future climate changes.

CW: I think we're going to be learning a lot about tolerance of all sorts of plants at the summer extremes of maximum temperatures, up to 45, 46 degrees or even the complete horror, the first time in Melbourne we're going to have a 50 degree day sometime in the next five or 10 years. And then the duration of heat waves.

So some things we know are going to do well, like the crepe myrtle, Lagerstroemia, the very traditional ornamental plant. We know that's pretty indestructible.

We’re going to have gardeners, qualified horticulturists, making a lot of observations, and getting the right spot is going to be important. It’s not like everything is going to be desertified. It's just going to be, does this plant now need shelter?

SA: Yeah, that's right. Microclimate is going to be even more important.

Weed and pest management

Q: Are you aware of any studies looking at whether citrus gall wasp causes longterm damage to the tree? It seems that many gall infested trees are very healthy and productive.

CW: I like to look up what people are saying about domestic gardens versus what commercial growers are saying. There's definitely studies that show a significant commercial loss of productivity, but not death, as far as I'm aware.

But in the domestic garden, my parents, for example, are citrus fiends, and have had lemons and grapefruit and oranges for decades, and some high levels of infestation of gall wasp, and they still produce huge crops, with some control. I'm going to do a bit more research.

AS: I don't know of any longterm studies, but we have to keep in mind that citrus, you can heavily prune to a stump and, it will generate. Which I don't think is advisable, necessarily. You're better off working with what you’ve got. But as far as a tree or shrub goes, they are able to regenerate themselves.

So I think a lot of it's about the fact that there’s probably too much fruit on most trees anyway, that we can cope with. We don't usually do any thinning of citrus. If it was a whole bunch of apples, we'd probably be more inclined to thin them off so it didn't snap a branch. It doesn't tend to happen with the citrus. They're a little bit more well spaced, so they don’t cause any structural issues.

I think it's probably a little overemphasized, because it might be part of that sort of tidy mind that sometimes we have, where we feel like we've got to control and reduce things, whereas probably it's not as bad as what we're making it out.

CW: Yeah. I think that the commercial farmer need for optimal growth in yield, which is absolutely fair enough if that's who you are, tends to inform our home gardening. And you don't want to be completely chaotic and spread disease and everything else to other growers, but it’s almost like a Jedi level of thinking that none of us have really done, to think what's the balance between super optimal and what's enough? Because we definitely over-fertilize our gardens, or some people do. Most so-called ornamental plants, native or exotic, don't need fertilizing.

Q: How do you control the cabbage white butterfly on brassicas?

SA: It is difficult, but there's a combination of methods I find works best. If you can spray with a product called DiPel, a bacteria, that will help to control the caterpillars. When they emerge from the eggs, they start feeding on the foliage and the bacillus thuringiensis kills them.

That in combination with hand picking. If you go around and find on the backs of the leaves some little yellow clusters of eggs or singular yellow eggs, just rub them off with your fingers.

And then there's also netting. It depends on how large your garden is as to what techniques you can employ.

AS: I really believe in the ‘get up close and personal with your veggies’ philosophy. And in this case, it means going around, inspecting every leaf, and squashing those caterpillars. Be ruthless.

SA: I agree. It’s about having an intimate relationship with your veggie patch and harvesting every day, if you can, for your lunch or your dinner. If you're there every day, you're more likely to see problems arising.

It goes for every pest and disease in your garden too, because if you're there, you notice it. You can get on top of it really quickly and avoid a big outbreak.

I think that's probably the biggest challenge that people have with their own veggie patches, that it becomes overwhelming at times, especially if diseases or pests take hold. But if you're out there every day and you fix a problem when it's really small, then you can have the best outcome.

CW: The best fertilizer and pest management is the footsteps of the gardener, peasant or the farmer.

Q: How do I keep possums out of my lemon trees?

AS: The possum issue is very difficult. If you can isolate the tree, you've got a better chance.

If you want to exclude possums, you’ve got to be having at least a 1.2 meter gap between where they can jump from and where they can get into the tree. So, whether that's the top of a fence or from the ground or a neighboring tree, that's the only sure way to create a gap.

because you might get enough growth. So you don't need to put much time into August.

Q: How do I get rid of Oxalis? Is it even a problem?

AS: You’ve got to know which Oxalis you’re actually talking about. Some are very ornamental and you don't have to do anything, but if you're talking about the one that's really flowering at this time of the year, which is the yellow flowering one, Oxalis Pescaprae, then most effective - I know it may not be popular at this time – is using glyphosate or Roundup when it's flowering, when it’s forming a new bulb. By attacking it when it's flowering you're stopping it from developing a new growth point for next year. And also the flowers on these yellow flowering ones, they actually have exploding seed heads. So, if you can do anything to actually stop it setting seed, that would be cutting the tops off.

The other thing is you can just cover things up. I'm a great believer that if you've got something in the ground you're not liking, then covering it up with a whole layer of paper or cardboard and then starting again, the no dig method, actually can be quite successful, because you're stopping all the sins down there underneath the layer. And then you just build again. As long as you don't disturb and turnover, then you can get some success that way.

CW: I once destroyed a lawn to grow veggies and in doing so disturbed the Oxalis and ended up with an Oxalis meadow. So then I had to cover the thing for 18 months.

Having said that, in other large veggie gardens that I’ve had, you have them popping up, and as Andrew says, if you shade them out, whether it's covering them at certain times of the year, or just the veggies themselves growing up during the growing season, you can learn to live with them. But it's pretty overwhelming when they go off.

About the Gardens

Q: Are the Burnley Gardens currently open?

AS: Yes. Apart from the field station, which is a separate area that the public can’t go in, the gardens remain open. We don't have any gates, so there's always access through the Swan Street or Boulevard entrance.

Q: Are there any public programs running at Burnley?

AS: Yes, we have a fantastic group called the Friends of Burnley Gardens. They're a volunteer group that raise funds for special projects in the gardens, and they run some public programs. Go to the Friend’s of Burnley Gardens website to have a look of what's coming up and what's available.

Q: Does Burnley have a plant identification service, where home gardeners may be able to have unknown plants botanically identified?

AS: There’s no formal identification. We still get lots of phone calls for plant identification purposes, and I think this is a throwback from when there was a plant advisory service next door at the Department of Agriculture. So occasionally those calls do come through to me. Sometimes people just email me. It's a service we provide just of normal working arrangements, just to help out for the public.

Q: When will the Burnley Plant Guide be available?

AS: It’s a resource that’s available to current students. It’s quite a large ongoing project, where they're trying to release that for non-students. It has been going on for a little longer than anticipated, but all going well, it will be available towards the end of this year.

This event was originally hosted over two live sessions. You can view the webinars, including the complete Q+A sessions, on-demand. Click for the first session and the second session.