Citrus Masterclass: Grow in ANY Climate!

Scented blooms, glossy leaves, and sweet and tangy fruits sum up the compelling case for growing citrus. They’re a real splash of garden sunshine! There are so many tempting types to choose from: oranges, limes, grapefruits, tangerines, kumquats and calamondins, as well as curiosities like the buddha’s hand citron or the knobbled fruits of kaffir limes.

I’ve grown apples, cherries, nectarines, and a host of soft fruits, and now – at last! – I’m starting my citrus collection, but I needed some advice. I visited Dr Shahnaz Camatchee, a truly inspirational citrus grower in London to glean her expert tips for growing these delectable fruits, no matter your climate.

Best Citrus for Beginners to Grow

I was blown away by Shanaz’s small suntrap garden, which was jam-packed with around 40 citrus plants in containers. My first question, as an eager first-time citrus grower, was what kind of citrus she would recommend for beginners to start with. She had no hesitation in recommending lemons, praising their hardiness – they can cope with temperatures down to around 23ºF (-5ºC) – and their talent for providing a constant succession of fruits. It’s entirely possible to have buds, flowers, baby fruits and mature fruits all on the same plant at the same time, so once you have a lemon tree you’ll never need to buy lemons ever again!

Where to Grow Citrus

When you buy potted citrus, sooner or later the roots will fill the potting mix and you’ll need to pot them on into a slightly bigger container. You can pot on gradually whenever plants get a bit rootbound in their pots. Needless to say, if you’re growing in a warmer climate then your citrus could be planted in the ground instead, as they won’t need special treatment to keep them cosy in winter.

A soil-based potting mix is best for long-term potted plants, and because citrus loves a free-draining soil, mix in about 20 per cent by volume of grit. The best time to pot plants on is usually in spring with the return of warmer temperatures and renewed growth.

Most citrus hail from warm, Mediterranean climates, so they need plenty of sunlight to help form buds, blossoms and fruits. In cooler climates like mine a greenhouse or sunroom makes growing citrus a more realistic prospect, especially if the plants are given a little extra winter protection in the form of horticultural fleece or bubble plastic. But if you’re growing in a warm climate then the sky’s the limit!

If you are gardening in a warmer climate, interestingly you might find that your lemons are still green even when ripe. That’s because it’s the drop in temperature in winter that causes the yellow coloration. The best way to check if any citrus fruit is ripe is to just press with your finger. If it leaves a dent, it’s ready to be harvested. Twist the fruit and gently pull to release it from the tree.

How to Water Citrus

Like many crops, citrus prefer rainwater, so collect what you can and use this if possible. Container-grown citrus can dry out very fast in warm, sunny weather, so inspect plants regularly, and water until it drains out through the holes at the bottom of the pot.

Plants need less water in the winter months and can be left to dry out a bit between waterings. Whatever you do, don’t leave citrus sitting in water, and use lukewarm water if you can. Ideally, when it’s cold, bring your collected rainwater inside to warm up a little before you apply it.

Watering containerised plants can be a challenge, but Shahnaz has a secret weapon: a moisture meter. She uses the probe to instantly check how moist the potting mix is. “More citrus are killed by overwatering than underwatering,” she cautions. “Do not leave the pots standing in water. Make sure they are actually raised up – you can buy pot feet – and make sure that there are plenty of drainage holes.”

If you’re growing citrus indoors you may need to mist the plants with water to keep humidity high.

Feeding Citrus

Feeding is another aspect of growing citrus that needs special attention. Poor nutrition means lacklustre growth, yellowing leaves, and no flowers or fruits. Many types of citrus form fruits during the cooler months, so they need a winter feed that is formulated to support flower and fruit development.

Citrus growing in the ground should do well with a generous annual mulch of garden compost, followed up with regular applications of a balanced organic fertiliser. Since Shahnaz grows her plants in containers like I’m going to, I quizzed her on her feeding regime.

“With citrus you can feed them throughout the year,” she said. “In summertime, every time you water give them a feed, in wintertime it's only once a month. In wintertime they have their specific citrus feed because the fruit that sets in the summer is actually going to mature in the winter.”

Shahnaz shared the secret behind her citrus growing success. “I have recently found a magic potion: fish poo water! I have two fish tanks and once a week, when I do the water change, I get about 70 liters (18.5 gallons). That waters the entire garden, and I have had five times more growth, and more baby fruits have set. I have actually ditched all the citrus commercial feeds, I'm just relying on this. I just water as normal, and it's feeding at the same time.”

Controlling Mealybugs on Citrus Organically

One of the most dreaded pests that Shahnaz sees are mealybugs. The only solution she has found that really works is Castile soap, which is an olive oil-based liquid soap. She dilutes 15ml Castile soap into one liter of water, which she pumps onto plant leaves using a pressure sprayer, either preventatively or when mealybugs are present.

Taking Citrus Cuttings

Shahnaz was kind enough to give me some lush, leafy cuttings without flower buds, which is perfect for propagating more plants. To root cuttings, use a multi-purpose potting mix with a few handfuls of perlite mixed through to ensure a really free-draining mix. This is important for citrus so they don’t wallow in water.

Aim to take cuttings in the cool of the morning when the foliage will be full of water and nice and plump. If you can’t process them straight away, pop your cuttings in a little plastic bag so they don’t dry out.

Trim your cuttings so they’re about 5-8in (13-20cm) long, making a clean, sharp cut just below a leaf joint. Remove all but the top few leaves using a razor-sharp knife or pruners for a clean, precise cut. A blunt cutting edge could crush the stem rather than cutting it, opening it up to disease. To finish, cut off all but the top few leaves to reduce water loss by transpiration from the cutting.

Dip your cuttings into some hormone rooting powder to help stimulate new roots then push them into the potting mix. Secure a clear plastic bag over the top of the pot to create a warm and humid environment which the cuttings will love. Place them on a bright windowsill, but out of direct sunshine so the plants don’t get too stressed out. Once they’ve started showing some fresh new growth this indicates that they have rooted, and at this point you can pot them up into individual pots and grow them on.

Growing Citrus For Health

I was impressed by how productive Shahnaz’s citrus trees are, but she doesn't stop at harvesting just the fruits. “You can boil the leaves for home-brewed citrus tea. The leaves when you crush them have that lovely smell, and you can use them to flavour your salad, your rice, whatever you're cooking.”

Shahnaz is not just a horticultural wizard, she’s a doctor too, and she’s keen to point out the health benefits of growing citrus. “Gardening overall is so beneficial to your mental state and your physical state, the benefits are just enormous, and being a GP I prescribe gardening to patients. Tender loving care, seeing something grow, it's that joy, and it's releasing all those good chemicals. It's why I love gardening.”

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