Winter Citrus Care

Harvesting Citrus

How to Tell When Your Citrus Fruit is Ripe

Winter is peak harvest time for many citruses. There’s nothing better than stepping outside and picking your very own fresh and delicious mandarins, oranges, lemons or limes. But how do you know when it’s the best time to pick citrus?

Unlike many other fruits, citrus fruit won’t ripen or become any sweeter after picking. So, it's important to only harvest fruit when they're properly ready. Commercial citrus orchards use special tools to measure the ripeness of citrus fruit, but the best way for home gardeners to test ripeness is to try one! Once the fruit is the correct colour (e.g. oranges and mandarins with bright orange skin), pick a fruit and see if it's as juicy and sweet as you'd expect. If it's not, wait another week and try again. Sweetness and juiciness increase over time, but over-ripe fruit can start to become less juicy.

Why Do Ripe Oranges Start to Turn Green?

Don’t be concerned if your once-orange Valencia oranges start to turn a bit green. The longer the fruit’s left on the tree during warm weather, the more chlorophyll (green pigment in plants) starts to accumulate in the skin. It doesn’t adversely affect the sweetness or the taste of the orange at all. In fact, many people think that these re-greened oranges taste better! Valencia oranges can be left on the tree for several months.

Common Winter Problems

Why Does My Citrus Have Yellow Leaves?

Some citrus trees are less cold-tolerant than others, so their leaves can suddenly yellow with the onset of frosts or cold weather. There’s usually no need for concern, it just signals that the plant is struggling with the temperature. It isn't actually due to a lack of fertiliser, so don’t fall into the trap of feeding. It won’t hurt to throw a frost cloth over the tree, or you can just move potted plants to a warmer position. Otherwise, wait for warmer weather to return.

If the leaves yellow at any other time of the year, the problem is likely to be either a nutrient deficiency, inconsistent watering, or a stress response to insect pests.

Winter Feeding, Mulching & Watering

Winter Feeding

Citrus plants are heavy feeders, so they like to be fed well and often while they’re actively growing. During winter they are slower, so it’s best to keep feeding to a minimum or skip it completely. But, at the tail end of winter, it's time to start feeding citrus trees generously, to prepare them for the busy spring season. Apply a complete citrus food, such as Yates Thrive Citrus & Fruit Granular Plant Food around the root zone of in-ground and potted citrus trees, then water in well.

Winter Mulching

Apply a fresh layer of mulch, such as pea straw or bark chips, around the root zone of citrus trees. Mulch helps retain moisture in the soil, regulates soil temperature, suppresses weeds, and provides a nutrient-rich environment for beneficial microorganisms. Mulch really helps to protect the roots of citrus trees from temperature fluctuations and extreme weather conditions during the winter months. However, prevent the mulch from directly contacting the base of the trunk, as this can encourage Collar Rot Disease.

Winter Watering

Keep the soil or potting mix adequately watered to maintain consistent moisture. Too much water can lead to citrus fruit splitting. Insufficient moisture can adversely affect fruit quality.

Winter Pruning

Prune off Rootstock Growth

If there are shoots growing from beneath the graft union (the bumpy bit at the base of the trunk), trim these back flush with the trunk. These shoots come from the tree's hardy rootstock, but they won’t develop the fruit you're after. Typically, they’re viciously thorny and will eventually take over from the fruit-bearing tree if not removed.

Revive an Old, Unhealthy Citrus Tree

As citrus trees age, sometimes they become less productive. It's fixable though, you can rejuvenate your older citrus trees and encourage them to produce more fruit during the winter months, by pruning them hard.

Hard pruning means cutting back a significant portion of the tree's branches, usually removing up to one-third of its growth. You can use a pruning saw or chainsaw for this job. While removing this much may seem drastic, it can actually help rejuvenate the tree by promoting new growth and improving air circulation within the canopy. The outcome is a healthier tree, with better fruit production in the long run.

When hard pruning older citrus trees, it's important to make clean cuts with sharp pruning shears. Focus on removing any dead, diseased, or crossed-over branches, as well as any branches that are growing too close together. Thinning out these overcrowded branches allows for better air circulation and light penetration.

After pruning, give your citrus tree a generous drink of seaweed solution to help it recover.