Question Time 52!

Another Q&A packed with practical gardening advice, from curl grubs and sick olive trees to thrips, blueberries, wicking beds, Boston Ivy and growing your own passionfruit.

🌿 Plants Mentioned

Vegetables & fruit

• Tomato — Solanum lycopersicum
• Cauliflower — Brassica oleracea var. botrytis
• Blueberry — Vaccinium spp.
• Lime — Citrus × aurantiifolia
• Lemon — Citrus × limon
• Black Passionfruit — Passiflora edulis

Ornamentals & natives

• Olive — Olea europaea
• Lavender — Lavandula spp.
• Rosemary — Salvia rosmarinus
• Ornamental Pear — Pyrus calleryana
• Snow Maiden Grevillea — Grevillea 'Snow Maiden'
• Crepe Myrtle — Lagerstroemia spp.
• Banksia — Banksia spp.
• Boston Ivy — Parthenocissus tricuspidata
• Climbing Fig — Ficus pumila

Plants mentioned as companion/mulch options

• Pea Straw — Pisum sativum
• Lucerne/Alfalfa — Medicago sativa
• Pine — Pinus spp.

🐛 This Episode's Questions

Curl grubs: How to tell beneficial yellow/orange-headed grubs from root-eating black-headed cockchafers.

Olive trees: Supporting mature olive trees showing possible signs of Verticillium wilt, including irrigation, soil health and root support.

Cauliflowers: Identifying whether slugs, snails or earwigs are responsible for damaged leaves.

Rice hull mulch: Why Keith doesn't recommend it as a mulch and alternatives including pea straw and lucerne.

Thrips: Why Success isn't effective against thrips and how Eco-Oil and Eco-Neem can be used.

Blueberries: How often to repot, pruning advice and maintaining acidic soil.

Limes: Why ripe limes can turn yellow — and what happens to their flavour when left on the tree.

Grevilleas & Crepe Myrtle: Can they grow together? Plus designing a garden to provide succession of flowering and attract birds.

Wicking beds: Advice for hot climates, reducing watering requirements and automated irrigation.

Boston Ivy: Why it can take a year to establish and whether it can damage a metal fence.

Passionfruit: Growing black passionfruit from seed, protecting plants from frost and why grafted passionfruit can become invasive.

🧰 Products & Resources Mentioned

• Original LOWY No.1 Anvil Pruner – www.backyardbotanist.com.au
• Neutrog Populate – https://neutrog.com.au
• Neutrog Go-Go Juice – https://neutrog.com.au
• Munash Mineral Rock Dust – https://www.munashorganics.com.au
• MycoGold – https://www.biostim.com.au
• Eco-Oil – https://www.ecoorganicgarden.com.au
• Eco-Neem – https://www.ecoorganicgarden.com.au
• Clyde Compost – https://clydecompost.com.au
• Digger's Club – https://www.diggers.com.au
• The Plant Runner – https://theplantrunner.com

🏆 Plant Runner Giveaway: Congratulations to Gerry, this month's winner, for her question about her 18-year-old olive trees.

Happy gardening! 🌱

Where you can find all things Muddy Boots!

Website: https://www.muddyboots.net.au/
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Transcript

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SPEAKER_01 0:00

Hello, I'm Elizabeth, an obsessive backyard gardener, who might be able to offer you a couple of tips.

SPEAKER_00 0:06

And I'm Keith, a landscape consultant, and I'm also passionate about gardening.

SPEAKER_01 0:11

The one thing we both have in common is muddy boots. Welcome everyone to another QA. As always, we have a load of great questions for Keith to get through, but before we start, we need to announce the three lucky winners of our latest giveaway from the original Lowy and the Backyard Botanist. The original Lowy number one anvil pruner is designed to handle tough pruning tasks with ease for medium to large hands, and is equally at home in either the garden or the workshop. A really great prize. So our three winners of these fabulous pruners are Andrew, whose Instagram account is Grandy Andy. That's number one. Julie, and her Instagram is Julie A.Burton2. And Allie, whose Instagram account is a.macing. Congratulations to you all. We will be in contact with you shortly to arrange delivery of your prize, which you will love. Okay, Keith, let's get started on our first QA. We have got the first question from Lee. He says, I've just dug up some lawn to start another vegetable bed, and I've noticed white curl grubs in the soil, the ones with the yellow head. Last season I had a bed, I had a bed that struggled. The plant started well but then struggled for the rest of the season. I had a tomato plant that was healthy to start with but eventually died. Is it possible that these grubs were the reason for the poor performance? And if so, how do I get rid of them? Everything else in the bed grew well.

SPEAKER_00 1:45

Well, I'd say that the tomato is more to do with um maybe pH in the soil. Um that's something that that that really ties them, ties them down and really makes them either go or not. Um Lee sent a photograph of the actual um curl grubs to me. Um and the fact that they've got an orange head means that they're not going to be problematic in the soil. If they had a blackhead, they are problematic. Because black-headed and we call them cockchafers, black-headed cockchafers eat roots of plants, roots of of turf, the works. And then that's the end of that. But the the orange-headed or the yellow-headed cockchafer, they actually eat dead vegetative matter. So in the lawn, for instance, he would have seen them in the lawn because they were in there eating the thatch layer that's in that lawn area. So that's that's um that's comes with older lawns, and that's where you'll get the curl grubs. They're they're not as I said, the the one you've got to worry about is the one that they have in the turf industry and on golf courses, where it is the black-headed cock chafer, and then during the uh during the the the late spring into summer you you see these black beetles, and that's uh that that is the you know the the life cycle starting all over again. So no, you haven't got a problem at all, but you you I would just be suggesting you get as much compost and go-go juice and um rock dust into those into those um beds that you're uh you're gonna be growing in, and I think you'll be perfectly fine.

SPEAKER_01 3:26

Okay, fantastic. Our next question is from Jerry. I have two 18-year-old feature olive trees in my front garden. They are in a large raised bed and have always been happy and healthy, producing lots of fruit. Until now. One of the trees has developed what I think is verticillium wilt. Random branches are dying with the leaves turning brown while the other branches around it continue to do well until they don't. We have been cutting out the dead branches and have given the tree a good feed, but are very concerned. Two factors changed last year. One, we added irrigation to the surrounding plants in the same garden bed. And two, the trees had olive lace bug last year, which we were able to control, but wonder if this may have weakened the tree. The prognosis from Google isn't good. Do you have any recommendations as to how to proceed to try and save the trees?

SPEAKER_00 4:16

Yes, um I'd recommend that you cut back on irrigation and do not apply any fertilizer at this particular stage because that could send them into a bit of a chock uh shock. Uh, I would be suggesting that you get yourself some neutrog populate, which is P-O-P-U-L, and then the the the numeral eight um and and apply that at recommended rates. Sea sole is also another great thing that you can be adding to the to the soil because it'll help stimulate root growth and and cell um production, and I'd be doing that on a weekly basis. And then to try to patch up and and rebalance everything, I would suggest that you get in there and and apply some monash mineral rock fertilizer. So the moneash rock dust, get in there and sprinkle that around the root zone of the trees, not the trunk of the trees. And then if you like, I would be suggesting that you maybe go into some companion planting and stick some some plants that like those sorts of conditions around olive trees, and that would be things like lavender and rosemary. Um, and then of course, um if you uh if you really wanted to go right out there and do the right thing, get yourself a prepping fork and get some mico gold down into the where the root systems are, and that will then strengthen the the the root systems up and give it a much better chance at uh coming good because they look absolutely fantastic, olive trees. Yeah, they do not have a lot of different things. I keep on thinking back to your beautiful olive olive trees at your place. At my old place. They were just magnificent standards, weren't they? Yeah, they were massive, gorgeous.

SPEAKER_01 5:54

Um, what is verticillium wilt?

SPEAKER_00 5:56

And so is that that's verticillium wilt is is a is a fungal disease, and it's something that that you would notice more on on the likes of um uh tomatoes. So they'll get either verticillium or or fusarium. And these are these are fungal diseases, and that's why going to the populate, for instance, it's going to be then providing those plants with the microbes that are going to be fighting off the nasty ones. Okay. Build up build up all the things in the soil by using the the the the the the populate, the the monash rock dust and the you know the the the mycogold, and I tell you it that should set them up and they'll be bouncing back for sure.

SPEAKER_01 6:37

Now we have a question from Jennifer. I need help with my cauliflower plants, which are being eaten. I'm not sure what is eating them, but have noticed heaps of slugs in the soil. So I'm guessing it's either slugs or earwigs. It was growing amazingly, and then two days later it wasn't. So I'm feeling that I may have to cut it off and wait for the next one to grow. What do you think, Keith?

SPEAKER_00 6:58

Um I'd be suggesting that you um you actually just give them a really, really good feed. A really good feed. Um thinking about that sort of a situation is is that there's an imbalance happening and you need to get on top of that that imbalance. Um I think that um feed with what? Feeding feeding it with with because of the the size of the plants, I think I'd be feeding them with with um uh go-go juice. I give them a dose of go-go juice and then some compost around them. Yep. Um I would probably suggest that it would be snails and slugs at this particular time of the year. If you've got mulch underneath them, then it could be um earwigs that were coming up. And you can generally tell the the earwigs will will tend to give you little circular holes in the leaves themselves. So they go up there with their little tiny mouths and just chew around in one little spot. Um and they do that because their food's not available, which is normally aphids. So that's that's what the the earwigs tend tend to uh to feed on. But snails and slugs in this time of the year, this is when the the the little baby ones are just coming into into life, you know, so we're in that early, early season. So so I'd be getting getting stuck into that with um with some some liquid food, um, populate or go-go juice, and just try to you know force them along. Um, and then maybe next year think about adding stuff like the monash rock dust. That will just set your garden up for the high bricks level in your plants that won't be attacked by the pest and disease.

SPEAKER_01 8:36

Good stuff. Anastasia's question is next. Do you recommend rice hulls as a mulch?

SPEAKER_00 8:43

Um no, I don't, because they they're just about pure carbon. So what what that they they might retain the moisture in the soil, but they're not adding anything good really into the soil because um the hulls themselves are carbon, so therefore the microbes are you are stealing the nitrogen deep in the soil in order to break the carbon down. Um and and the other thing too is that they can be blown around and all the rest of it. So it's not a it's not a great um it's not a great mulch as far as I'm concerned. I I wouldn't rate that very highly. If you're going to be using it because you've you've got plenty uh you know access to it, then put put in a nitrogenous fertilizer over the top of it. So sprinkle some um blood and bone over it or some rooster booster or something else like that. Feed the microbes rather than than starve the microbes, so the microbes are not putting the their goodness into where it should be, which is the plants.

SPEAKER_01 9:40

So, what alternative that looks a bit similar to a rice hole? I'm trying to think what it would look like.

SPEAKER_00 9:44

Um well some uh peak. Colour wise pea straw, lucerne, that sort of stuff. But if you're going to be using uh pea straw, make sure that you haven't got doves around because the doves will just get in there and they'll move it everywhere, trying to find the peas that might be in the in the pea straw. Yes, that'll be. I have to I put pea straw down this year and I use Brunning's pea straw. Um and I've had to put a net around it because otherwise the doves would be in there just flicking it everywhere.

SPEAKER_01 10:11

Liz has the next question. I've had an issue over the past few years with trips in my ornamental capital pear trees and underplanting of Raphael's Snowmaiden. I've tried a product called Success, as was recommended to me by a local garden centre, but had zero success. And now they are back with a vengeance. They're distorting the growth with yellowing leaves, and the plants look looking generally unwell. I would love your suggestions on what I could use to eradicate them, and I will need and will I need to treat the soil as well as spray the plants.

SPEAKER_00 10:43

Um well you're wasting your time using success because obviously. Yeah, because um success is for is for caterpillars mainly. Um and thrips are not going to be not going to be phased by putting that on, so that's the reason that didn't work. Um and in the soil, yes, most most insects pupate in the soil, as well as in the leaf litter and bark crevices. I always go back to the old favourite for spraying for thrips and for most of these bugs that that suck living daylights out of your out of your leaves and things, going into using the eco oil and the eco neem. So the old the old saying of um how many how many mil of of eco oil?

SPEAKER_01 11:28

Twelve to twenty oil.

SPEAKER_00 11:30

That's right, yep. Twenty-five mil of eco oil. Yep, uh twelve round. Twelve mil.

SPEAKER_01 11:37

I don't know, twelve and twenty-five. Which one?

SPEAKER_00 11:39

So neem. The smaller one. Smaller bottle which comes in. The more expensive stuff.

SPEAKER_01 11:45

Yeah, and twenty-five and twelve.

SPEAKER_00 11:47

And twenty-five mil of the eco oil, mix those together into a five-litre sprayer, and then you need to spray the back side of the leaves as well as the front side, because if you spray the if you spray just the front, it ain't getting to the back, and that's where those thrips and all the other things will tend to tend to be. Um the eco oil will smother the smother the bugs and and and kill them. The neem will then become systemic if you spray it on a regular basis, so that anything that comes along later on to chew and suck, it'll kill those good. And then I'd suggest you get out with your munash rock dust and give that a bit of a dose just to increase in increase the soil microbes in the soil and build up the bricks level of the plants that will ward off pest and disease.

SPEAKER_01 12:34

Thank you, Keith. Kimberly is next. I have a few blueberry bushes in fairly large pots, which we repotted last year. They haven't outgrown their pots yet, but I would like to know how often the soil should be replenished. I'm also keen to know your approach to pruning blueberries. Is it necessary? And if so, when's the best time and what is the best way to prune them?

SPEAKER_00 12:54

Um if you potted up last year, then uh they'll require a light trim now just to shape them up to allow light and uh air penetration. So go through and just give them a nice light prune, and they'll they'll be fine. And that will that will then force the the plant to provide energy into the growing of the blueberries. Um plants in pots, they should be changed every three to five years, so in the middle of winter, and always use an acidic potting mix. So you you can buy those from the big green warehouse. It is specifically for acidic loving plants like camellias and azaleas and these sorts of things, but they're also great for blueberries. And then once you've got them in the pots and growing, go and get yourself some pine needles and sprinkle that as a nice thick layer over the top, and then I think that will be fine.

SPEAKER_01 13:45

There you go. Uh now we have a question from Carolyn. She says, I have a lime tree which is planted beside a lemon tree which has never flowered or fruited. I have had many seasons of beautiful green limes, but this year some are green and others are bright yellow and taste like lemon. Is this normal or is the plant lacking something? I always feed it well with neutro products.

SPEAKER_00 14:07

Caroline, there's absolutely nothing wrong with your limes except maybe not enough gin and tonics. You might have to uh start having a few more gin and tonics. We've been conditioned to think of limes as being green because when you go to the supermarket, you go and buy green limes. Limes are exactly the same thing as lemons, they're a citrus, and they will eventually become yellow.

SPEAKER_01 14:31

But they're bright yellow.

SPEAKER_00 14:33

Yeah, and that's what happens. So they've been left on the plant for too long. So therefore, they're they're exuding a lot more sugars and they're making them a lot sweeter. So they're they're more like a more like an orange than they are a lemon in that respect. Yeah. So they'll they'll always colour up. You know, if you leave them on the plant long enough, they'll go from the beautiful spicy uh lime that you love in your in your cooking, because it's got that real, you know, bite to it. Um, but if you leave them on the bush, they'll just become yellow. And that's where they lose lose their flavour overnight.

SPEAKER_01 15:05

So over the stuff.

SPEAKER_00 15:06

Just like the chewing gum.

SPEAKER_01 15:07

The chewing gum?

SPEAKER_00 15:08

Yeah, the chewing gum on the bedpost overnight loses its flavour.

SPEAKER_01 15:12

Oh yeah, it would be revolting. Helen's question is next. I have a ten by ten area outside a bedroom window that I'm trying to plant out and bring birds in for my granddaughter to look out at and love. I was going to plant a crepe myrtle in the middle of the bed and circle it with a number of beautiful pink gravilla called majestic, although I'm finding it very difficult to find these anywhere. When I told the Native Garden Centre what I was trying to plant, he told me I could plant I couldn't plant the myrtle and gravillias in the same garden bed. Is this an accurate warning? And if it is, how do you know what plants go with each other?

SPEAKER_00 15:47

Hi, Helen. Lovely to hear from you again. And um, as I said in the email that we responded back to earlier on, I've never heard a greater load of rubbish in my whole life.

SPEAKER_01 16:00

Right.

SPEAKER_00 16:01

Um crepe myrtles and gravilliers, why won't they grow together? Well, there's no absolutely no reason. Crepe myrtles will grow in just about any condition you can come across without any love and attention. And gravilliers are exactly the same. The only problem that may may occur might be problematic where the soils are very high in phosphorus. So um, and on the Mornington Peninsula, where I know that you you live, you don't have a high phosphorus content in your soils down there, so the likelihood of that happening is absolutely minimal. Um so we get back to this phosphorus toxicity thing, and we've we've spoken about it before. 82% of Australian natives do not suffer from phosphorus toxicity. However, gravillias and banks are those that that can suffer. But if you use Clyde Compost, the levels of phosphorus in there is not going to have one little iota of problem with uh with the with your uh thingo. With regards to your choice of of uh gravilia, no wonder they're hard to find, as the only grower of that particular variety of um of gravelia is in a new in a in a nursery in New South Wales called McClay Valley Nurseries. And after consideration about what you're trying to achieve is of a concern to me. A crepe myrtle in the middle of the bed surrounded by these gravillias will mean that you won't see the crepe myrtle at all because these gravillias will get between four and a half metres high with a spread of between one and a half and three metres. In order to attract bird life into your garden, you need to have successional flowering to keep the birds coming in. So I hope this by in some way addresses a lot of those concerns that you have with your plants.

SPEAKER_01 17:55

What are you going to plant, hey, Keith?

SPEAKER_00 17:56

Absolutely. There's lots of things that you can plant. Um and I gave her some suggestions. Oh, you did. Good, good, good.

SPEAKER_01 18:02

Okay, now we have a question from Jess. We love Jess from Mona Vane. I live in Warren, New South Wales, which gets very hot in summer with many days over 40 degrees. I'm wanting to start a decent sized vegetable garden, but don't have a good watering system relying on moving hoses. Thinking of the health of the veggies I want to produce, should I put money towards plumbing in a w plumbing in a watering system or keep with the wicking beds which I just fill up when needed? After listening to your last podcast about earthworms not being able to access wicking beds, I'm wondering which is best for a poor-time gardener, wicking beds or raised beds.

SPEAKER_00 18:38

Hi, Jess from Warren. You have a beautiful garden there, love. Um if you've used the wicking beds last summer and you found them to be successful, then I would suggest that you stick with them. Uh if I had my preferences, then I'd be looking to order on your next Clyde Compost delivery to Warren bags of their lignite humates and apply it at 5 litres per square meter, mixed in with Clyde Compost at 10 litres per square metre. The best thing about this possible mix mix is that it will have an amazing water holding capacity because it's the carbon content in the lignite humates that will hold up to 400% of its own size and area in moisture, and that will reduce your your watering requirements. If plants have available water at their root zones, then transpiration is minimized enormously. So I think that's just a great way of doing it. With regards to an irrigation system, if you're going to put one in, uh I would suggest that you have a look at the Dan sprinkler system. There is a company in New South Wales called Dural Irrigation, and they have the um have the Dan sprinklers. Um and you need to set those up off a 20 mil supply of polypipe attached to a tap and where you can actually have an orbit beehive battery-operated uh controller on it with um one station, two stations, or four stations. I've got four stations and mine, and then you can have a Wi-Fi hub, which just goes into your PowerPoint, and that will give you control over that that irrigation system, whether you are up in um i uh at an at an IGA expo, somewhere uh up in Queensland or somewhere else. You can turn your irrigation system on from up there. So, how about all that, Jess? And uh if you need any more information, call me.

SPEAKER_01 20:36

There you go. Fanella has the next question. I planted a badge of Boston ivy against a Cularbon fence in December last year, which the nursery said will climb anything. I'm concerned that it hasn't climbed much yet, and also wonder if it's safe to grow it against the metal fence or if it might cause the fence to rust.

SPEAKER_00 20:54

Boston ivy is one of the best climbing plants that you can put on just about any surface whatsoever, um, as opposed to say um climbing fig. So the thing about Boston Ivy is that it is a deciduous climber. Um and you'll notice that if if you purchase a Boston ivy this year and stick it in the ground, it will sit basically for the whole year. And the reason for that is that it needs to establish a decent root system throughout the soil. Now uh without getting too technical about how that how this system works, uh suffice to say that the the the Boston ivy sticks to the wall using uh calcium that it takes out of the soil in order to to use those pads to stick. And it's the calcium that makes it probably one of the best um forms of of of attaching itself to any surface because it's not invasive, it's not gonna degrade or damage uh any surface that it's growing on. Oh, okay, good. And now Getting back to the part about the calcium, it needs to get calcium out of the soil first. And the only way that that calcium can be taken out of the soil and supplied to the plant is not necessarily through microbes that live in the soil, but the beneficial fungi that live in the soil that that make that that the calcium that is in the soil available to the plants. So that's probably one of the one of the best ways to say it.

SPEAKER_01 22:27

So does that make sense? Does vanilla will vanilla have had have that beneficial fungi in the soil already, or depends does she need to have added a potential?

SPEAKER_00 22:33

It will come, and if she uses, say, something like populate or go-go juice, um, that will that will help. Or if she uses something like myco gold. Yeah.

SPEAKER_01 22:44

She had to put myco gold in the bottom of the hole. She can still sprinkle, she can still get some. Yeah.

SPEAKER_00 22:50

So that's what I'd I'd be suggesting. You know, it's it's it's the the Boston Ivy is probably one of the least aggressive of all the climbers, but it will sit for a year. And I think you've got some Boston ivy here. It's sitting in the and what's it been doing?

SPEAKER_01 23:04

Hasn't grabbed at the wall yet, but I only put it in a couple I don't know, I can't remember now. Uh autumn. I put it in autumn and nothing.

SPEAKER_00 23:10

So it doesn't, it doesn't it needs to sit and it needs to get that symbiotic relationship happening with the good bugs in the ground first.

SPEAKER_01 23:17

So it's busy working underground at the moment, and next year it will suddenly attach itself with those calcium-y calcium little suckers. Suckers. Okay, fantastic. Uh last question for this QA is from Jan. After listening to the latest podcast about passion fruit, I'm second guessing planting a black passion fruit Passaflora edulus. My grandkids love passion fruit, but they cost a fortune, so I've decided to try growing some. Up until a couple of weeks ago, it was thriving, but we've had some nasty frosts and it's looking rather ill. So after listening to your podcast, I'm wondering if I should abandon that one and plant another in a pot.

SPEAKER_00 23:54

Yeah, you look, you can. Um pots will will tend to attract and hold hold the the the heat around them in a in a better way than the soil will. Um I would be suggesting to you, Jan, that you actually grow your own passion fruits from the seeds of the black passion fruit. Um, and there's some seed companies around that diggers club sell the black passion fruit, the seed company sells them. There's lots of um, you know, they're available pretty easily from any of those sorts of things. The best position to grow um passion fruit is where they are facing east. Okay, so I've I've got I've got three in my garden, um, and the one that performs the absolute best faces due east. The other two face due north, and they are the most affected by the the cold conditions um and also the hot conditions. So if you can find a an eastern aspect, that's going to be the absolute best way to do it. They love plenty of food, so make sure that you've got a well-composted hole that you put them in. Um, and you generally get between five, three, five to seven years out of each particular plant. So have yourself a backup plan um, you know, in you know, after you planted your first one in a couple of years' time, think about another one, booting it, you know, growing a new one from seed. For goodness sakes, do not buy one that's been grafted because you will hate yourself, and so will your neighbours, because that stinking rotten graft will take over one day and it'll rule the world.

SPEAKER_01 25:33

Yes, we know about those. Okay, thank you, Keith. That brings us to the end of another QA podcast. So thank you again to you all for the great questions. Now all we have left to do is announce the winner of the very generous prize from the Plant Runner. And this month the prize is going to Gerry, who is working very hard to keep her 18-year-old olive trees alive. Congratulations, Jerry, we'll be in touch shortly. And to everyone else, don't forget to check out theplantrunner.com for your organic indoor and outdoor plant care needs and happy gardening.

SPEAKER_00 26:03

Happy gardening.

SPEAKER_01 26:05

Thank you for listening to Muddy Boots. For more information on today's podcast, please go to muddyboots.net.au and happy gardening.