Top tips for growing a healthy and productive citrus tree | Gardening 101 | Gardening Australia

Just down the road from me at his wholesale nursery at Brunswick Heads, expert grower John Mills has grown millions of citrus trees. And today John is sharing his tips for citrus success. How long have you been growing citrus? I started about 45 years ago and it was just one of those things that I really enjoyed. And how many varieties have you got now? I've got about 40 now. Wow. So John, these rootstock seedlings are quite packed in together, aren't they? Yeah, the most important part of the tree is the rootstock that you start with. And the reason why we grow them in the ground like this is to get that perfect root formation. Can you tell me about that over there? Which one's this? It's Trifoliata. It's a very good variety for home gardens. It's a semi-dwarf rootstock. A good average height it'll get to is about four metres. You can put all varieties of citrus on this. On the Trifoliata. If the ground is a bit wet or the ground's a bit dry, it's got a better chance of surviving than some of the other rootstocks. Why is that? It's just harder. It's just hardier. So tell me about the Flying Dragon. The Flying Dragon, it's a dwarf rootstock. See how the Trifoliata, the thorns are pointing upwards? Yep. With the Flying Dragon, they go out. With the smaller backyard, there's a bigger and bigger demand for a Flying Dragon rootstock. Can you plant them quite close together? You can. Yeah, you can probably plant a dwarf a metre and a half apart. Big trend is growing the citrus trees in pots now, but they'll always do better in the ground. Yeah. So this is where the magic happens, John. What have we got here? Now we've got a rootstock here ready to graft. So we've selected a Tahitian lime twig. We call it a bud stick. So what we do, we trim off the thorns and the leaves. So we trim them off neatly. And on that bud stick, there might be 15 buds. Is there a way in particular to select the bud stick? Yeah, you've got to make sure it's nice and firm. And it should match the tree you're going to put it on. So relatively new growth, but established. Yeah. OK, now we're going to trim the thorns and the leaves off the rootstock. OK, we're now going to make an incision to put the bud in. We'll come down about 30 millimetres. Then we go across, and that makes an upside down T. Yeah. We've prized the bark, opened. But just very slightly. Very slightly, yeah. And then we cut a bud. OK. Like that. It's important that they have a nice flat surface. Try not to put your fingers on the face of the bud. So then you just fit it in like that. Slip that in. It becomes part of the tree. A little bit of tape. Start off with that. So you see the bottom of the T? Just below the T. And then you start to spiral up. Ah, OK, so you're going over the budwood as well. You're going over the budwood and over the tape. You're taping over yourself all the time so no water can get in. Right. In three to four weeks' time, when we cut this off, we unravel the tape and you'll see a nice wide bud sitting in there. And is there a reason why you leave the leaves here on? Photosynthesis. OK, to encourage the growth. To encourage the growth. Yeah. How good is citrus? Awesome. Is there an optimum or an ideal time to be planting your trees? Spring, summer. In the autumn is optimum. In North Queensland, you'd be able to plant all year round. But maybe not in Tasmania. Not in Tasmania. That's right. So, John, all that hard work of what we've just seen, the processes of what you've been doing, is this your... That's it. ...the reward? Yeah. It's a Tahitian lime on flying dragon rootstock that we've nurtured for two plus years. And now we've ended up with this. Shall we try planting it? Let's do it. Tell me about your hole. OK, we have a nice square hole. So when the roots start to spread out, instead of going around in a circle, they'll find a corner and go into the corner and penetrate the corner. So we'll place the tree neatly in the hole. We'll then put a little bit of dirt like this. And then we'll put about 50 grams of slow-release fertiliser around there. And then we'll proceed to fill it up. It's important to only plant it to the height that it's already in the container because if you cover the bud union, it wouldn't be good. It could kill the tree. We always put fowl manure around it before we start. It's composted fowl manure. And then we'll put T2 emuls around it. And even though we've put a fair bit of fowl manure around it, a fair bit of emuls around it, our bud union is still well above the compost. Right. Right, it's time to water it in? Time to water it in. All around the small drip line of the tree, give it a nice soaking. Probably water it every three or four days for the first two or three weeks and then ease back to once a week. Right. And then after that, just monitor it. That's a good soak, isn't it? It is. Yeah, okay. So in the first year when you see the flowers, what should we do? I would pull them off. But some people can't bear to pull the flowers off because they've been waiting. They want to get some fruit. Even if it's one or two? That's right, even if it's only one or two. But what is the reason why you pull off the flowers? Well, if you pull off the flowers, then you don't get the fruit and then the growth will go into the tree rather than two or three pieces of fruit. To establish the root system. To establish the root system and the tree. It's got enough fertiliser in the ground to sustain it for a few months. The best time to fertilise citrus trees is July, August and then you give it another application at the end of the summer and keep your mulch up. Yeah, because that really holds down the moisture and the nutrients, doesn't it? Yeah, yeah. Beautiful. Do you feel all the same about all your trees or do you have favourites? I probably do have favourites, but I like them all because they've all got their different values and they've all got their different looks. So I like them all. I just love growing trees. Especially citrus. That's it.