More information on caring for your Citrus trees

Scroll down to find answers to common citrus questions and problems

Choosing the right location

• Citrus trees have been grown in the UK for hundreds of years and in the right spot are easy and really rewarding plants.
• They need plenty of sunlight and somewhere cool but not cold or frosty.
• In the UK that means they do need to be indoors during the winter to protect them from frost.
• In the summer they will be happiest outside on a sheltered patio but they will also do well on a windowsill or in a bright room or conservatory.
• Indoors try to keep your plant away from any radiators, under floor heating or draughts and if on a windowsill keep the leaves from touching the glass.

When can my tree go outside?

• Calamondins, Kumquats, Mexican Limes, Grapefruits and Orange trees should all be kept above 5C so can only go outside for the warmest months of the year.
• Lemon trees and particularly the mature Lemon trees can take cooler temperatures right down to 0 degrees and can go outside as soon as the night time temperature is above freezing. (They will even survive a mild frost if you get caught out).
• We always err on the side of caution when exposing plants to cold temperatures but we have had many reports from the South West and London of Lemon trees doing well outside when trained up walls or kept in pots on sheltered patios.
• If and when you do move your plant outside do be aware that a sudden change in light levels can cause 'sunburn'. To avoid this, place your plant in a partially shaded spot for a few days before moving into full sun or move it outside for a few hours a day until it has adjusted to its new position. Too dramatic a change in light levels can lead to blanching of the leaves and some leaf loss but over time your plant will recover and put on new growth.

Advice on Watering

Getting the watering right is crucial with citrus, the trick is to water only when the soil is dry to the touch and then to water heavily from the top of the pot. You should expect the amount of water your tree uses to change quite dramatically from summer to winter and according to the weather.

How often you will need to water depends on: Air temperature, wind, location (light/dark situation), the size of your plant in relation to its pot and the type of soil.

Both underwatering and overwatering lead to leaf loss and can eventually kill your plant.

How much water should I use?

Water at least 20% of the volume of the pot each time - so 200ml for a small calamondin in a 1L pot, - 1L for a large Lemon tree in a 5L pot.

When the surface of the soil dries out on top, remove the plastic pot from any pot cover or basket and water the plant heavily until the water runs freely through the soil and out of the holes in the bottom of the plastic pot. You might find it easiest to do this in a sink or outside. Don’t forget to throw the excess water away and never let the pot sit in a pool of water. As with most plants, citrus trees will absorb water better and more efficiently if watered in the cool of the morning or evening rather than in the middle of the day. Avoid splashing the leaves with water generally but particularly in the middle of a sunny day.

Things that will affect how much water your plant needs

• The higher the air temperature the more often your citrus plant should be watered, because it will be evapotranspiring more (or ‘breathing’ more).
• The more wind or draft around your citrus plant, the more water it will be using so it will need to be watered more often.
• If your citrus plant is very big in relation to the size of the pot, then the amount of water the pot will hold will not be enough to last it very long, so it will have to be watered very frequently, and thus it is more likely to dry out. In general, the plant should be 2 times the height of the pot. If it is any bigger, the watering becomes more difficult, and you should pot your plant into a bigger pot (see Repotting).
• In a hot summer, plants can need watering up to twice a day when in a small pot but in the winter months this might drop right down to once every 2-3 weeks. It is therefore important to adapt your watering routine as the seasons change, be wary of underwatering in the spring and overwatering in the autumn.
• Citrus plants generally like a well-drained, slightly acidic soil but they do grow well in a variety of soils and more dense clay soils taking longer to drain water through than bark based compost.

How do I know if my plant needs watering?

• If the top few centimeters of the soil becomes dry to the touch, then it is time to water your plant.
• By observing the leaves, you can also tell if the plant needs water. If the leaves start to curl upwards at the edges, or loose their normal glossy green colour, then your plant is already showing the first signs of stress and should be watered straight away.
• After watering you plant, it is a good idea to lift it up and feel the weight of it in your hand. You can then use that as a reference to judge whether the plant needs watering in the future. After a while you will begin to be able to judge quite accurately using this method.
• Sudden and dramatic leaf loss is almost always due to underwatering so watch carefully to catch your plant before this stage.

Symptoms of Overwatering

You should only water when the top of the soil is actually dry to the touch. Most problems come not from watering too much but watering too often. If you consistently overwater your plant, you will starve the roots of oxygen, and prevent them from functioning properly. They can start dropping their leaves a few at a time at this stage and if it continues can lead to root rot and eventually the death of the plant.

Advice on Humidity

• Your citrus plant will survive happily indoors in centrally heated houses as long as it is not too dry.
• There is a lot of conflicting advice on misting v.s. not misting citrus trees. We don't mist our trees in the nursery because it is normally fairly damp. We recommend that you only mist your plants if they are in a very dry warm room or if you find that the flowers are not setting fruits.
• If you do have a particularly warm house and you do opt to wet the leaves of your plant then it is best to do this either in the early morning or evening. In full sun, water on the leaves of your plant can act as a magnifying glass and scorch the foliage.
• If your plant is outside it will adapt to the moister conditions and higher light levels and will cope surprisingly well with wet conditions as long as the roots are able to drain properly.
• If it has been particularly hot and you are struggling to keep your plant well watered, you can splash the leaves in the evening when you are watering to cool it down and raise the humidity but avoid doing this in the middle of the day when the sun can scorch the leaves.
• In extremely damp conditions, for example, if you overwinter your citrus in a greenhouse or damp conservatory, it might be worth opening the windows in the middle of the day.
• Spent flowers and dead fruits should be removed regularly from both indoor and outdoor plants to keep the tree looking neat and to avoid fungal problems.

Advice on Feeding

When your Plants4Presents citrus tree arrives it will be well fertilized and should not need any additional feed for the first 4 weeks. After 4 weeks it is a good idea to start using the relevant citrus feed to keep your plant healthy.

• Most plants including citrus trees benefit from additional Nitrogen, Phosphorus and Potassium. General purpose and houseplant fertilizers contain these in various ratios. Citrus trees, however, also need high levels of trace elements including Iron, Calcium, Magnesium, Boron, Copper and Zinc to keep their leaves and fruits healthy. General house plant feeds and tomato feeds etc. contain Nitrogen, Phosphorus and Potassium (NPK) but not all the required trace elements.
• You can buy citrus feed (winter and summer feed) directly from our web site ...click here and we will send your citrus feed to you by post or by phone on 01825 721162
• Made to our own balanced formula this is what we use and recommend although of course there are other options available at your local garden centre. If using these, do check that they have a summer and winter feed and that they contain all the trace elements listed above.
• Summer Citrus Feed is used from March to October and contains more Nitrogen to help your plant put on fresh leaves and summer growth.
• Winter Citrus Feed contains proportionately more Phosphorus and Potassium to help your plant set and develop fruits.
• However, if you run out, either feed is better than none.
• In addition to feeding regularly, it is a good idea to top up your citrus tree compost every spring and to repot it at least every other spring to give it a fresh boost of nutrients.

When to feed?

• Use fertilizer every other time you water your plants in the growing period (when the new shoots appear).
• Outside the growing period, you will find that you are watering less often so every other watering might be once ever 3 weeks which is fine. The fruits will develop using the energy that has been stored up in the leaves and stems of the plants throughout the growing period.

Advice on Repotting

When should you repot?

Citrus plants need to be periodically repotted to maintain a healthy plant - once a year or once every 2 years for trees up to 6ft in height. For trees over 6ft you can usually just top up the compost once a year and repot every 3 or 4 years.

Normally our trees will be sent in a suitable pot and you won’t need to think about repotting for at least six months. However, if you are not sure, a good rule of thumb is if your citrus plant is more than 2 and a half times the height of the pot, then it is ready to be repotted.

Potting should ideally take place in the spring or early summer when the plant begins to show signs that it is growing. Sometimes you might decide to repot your tree in the summer because your plant has grown on a lot or because you are struggling to keep up with the watering. However, avoid potting up your plant in the late autumn or winter unless there is a good reason as it will not be growing and the roots won’t move into the new soil.

What kind of soil?

The size of the new pot should be large enough to allow a few centimeters of new soil around the edge of the old rootball. It can be repotted in any well drained mixture that is slightly acid. Probably the easiest solution is to buy a good quality container or ericaceous compost in a garden centre but you can also use top soil from the garden or 50:50 a mixture of top soil and ericaceous compost with a handful of sharp sand/grit/stones for extra drainage. The ideal pH is 5 to 5.5.

Guidance on Repotting

Remove the old pot (Turn the plant upside down and hold it soil in with one hand and pull the pot off with the other) If the roots are tightly knotted together, gently pull them away from each other so that they will then be able to move out into the new soil. Put a small amount of soil into the bottom of the new pot, lower the plant into the pot and fill up around the edges, compacting the soil gently with your fingers to make sure that there are no air gaps around the edge. Water the plant thoroughly a few times, to make sure the soil is wet.

Older citrus plants can be repotted into the same pot if needed. In this case you should cut away some of the root with a knife or secateurs (approximately a few centimetres) and remove as much of the old soil with your fingers as possible before repotting as above with fresh soil.

Problem solving

The trickiest thing with citrus trees is getting the watering right. Overwatering and underwatering are by far the most common cause of problems in citrus trees.

Overwatering is most common in the winter months or at the change of the seasons from summer to autumn and results in steady leaf drop, root disease and/or lightening of the leaves. Dropped leaves are normally leathery to the touch but if you hold off and really dry the top of the soil out before watering again you should see a full recovery.

Underwatering Not watering frequently enough or not watering thoroughly enough to ensure that all the roots receive water can result in a sudden and dramatic leaf drop. It is most common in the summer and in the spring when the amount of water your plant needs suddenly increases. If you have slipped up and allowed your plant to dry out completely don't despair we have seen even some of the most bare and forlorn specimens come back to life with the right care.

Overfeeding Generally it is much more common to under rather than other feed so as long as you are following the recommended dose you shouldn’t need to worry about over feeding. In extreme cases using more than the recommended rate of fertilizer can “burn” the roots, but this is rare.

Underfeeding Citrus trees are really quite greedy feeders and lack of nutrients leads to pale, sickly looking leaves and also a susceptibility to pests.

When the plant doesn’t have enough nitrogen and/or iron the leaves typically turn yellow and or mottled. Once this has happened you will need to feed regularly for some time to get the new leaves to come through green and healthy. Unfortunately once the leaves have got to this stage it is very difficult to return them to a healthy green and most people only get a partial recovery on the old leaves.

Sometimes a plant can struggle to absorb particular elements because the water is hard or the soil can become unbalanced over time leading to a lack of a particular trace elements. Eg a lack of calcium leads to yellow or yellow brown tips to the leaves

TOP TIP You can apply your citrus feed as a foliar feed to help get the nutrients directly to the affected leaves. Simply make it up at half strength and water the solution directly on to the leaves and new shoots. Be sure to do this in the morning or evening so that bright sunlight does not scorch the leaves.

If you find that despite a regular feeding regime the leaves are still coming through light in colour or mottled then you may have hard water and/or need an extra boost of nutrients – give us a call and we’ll be happy to advise.

Advice on Pests

Plants4Presents citrus trees are grafted plants sourced from reputable citrus growers in Portugal, Italy and Spain and it is extremely rare for us to have any problems with fungal diseases or viruses. However like all plants, citrus trees are sometimes susceptible to pests and insects. Sometimes these crawl from one plant to another or sometimes they might fly in or arrive on peoples clothing. Checking your plant every few weeks for signs of trouble will allow you to spot and treat problems before they get hold.

• Aphids - can attack the young shoots and flowers particularly in the Spring and Summer. Watch out for sticky residue on the leaves, green, brown, black or orange bugs on the shoots and/or white specks on the tops of the leaves (these are the shed aphid skins dropping from above). A general purpose pest spray or even just a washing up liquid and water solution will keep these sap sucking greenfly at bay. It is rare for them to get a good enough hold to do lasting damage to the plant but they can limit flower and therefore fruit production
• Caterpillars - like aphids these attack the flowers and young shoots. Butterflies lay their eggs in the flower buds and the baby caterpillars can do quite a lot of damage to the flowers and fruit crop if not caught early. A spray or simply removing all chrysalis and eggs by hand will solve the problem.
• Scale insect - scale is not common but it is quite damaging. Keep an eye out for any stickiness and for round brown circles on the undersides and veins of the leaves, on the branches or fruit. They will slowly weaken the plant and should be treated immediately with a biological pest control or spray (we like S&B invigorator as it’s organic but there are others available at your local garden centre). You will need to remove the visible round suckers – we find baby wipes the easiest but you can use a flat knife or a damp cloth but you will also need to use a spray to get rid of the juvenile scales or ‘crawlers’ that are invisible to the naked eye. SB Plant invigorator works well if applied regularly until they are gone or for a worse outbreak methylated spirits is on old gardeners trick which works wonders and surprisingly doesn’t hurt your tree if done occasionally.
• Cotton Cushion Scale – this is a rare pest but we have seen one or two reports in recent years and it is worth spotting early. The big adult cushions don’t even look like insects but underneath they are breeding hundreds little suckers which will feed on all the goodness from your plant.
• Mealy Bug - these white fluffy creatures are related to woodlouse. They live in the cracks and crevices of the branches and look like cotton wool or trapped fluff. If you do find them a specialist spray or biological pest control is the best way to treat them or in extreme cases methylated spirits applied with a paint brush right into the cracks and bark joins works well.
• Vine Weevil - adult vine weevil are up to 2cm long and leave jagged marks around the outside edges of the leaves they attack. However it is their larvae that do the most damage though, feeding on the roots of a wide range of house and garden plants and weakening them irreversibly. At the first sign of any trouble treat all your pots and houseplants with a nematode solution (See our sister site www.ladybirdplantcare.co.uk for more information on environmentally friendly pest control) and be vigilant for their return.

If you need any help identifying pests on one of our trees then please do get in touch. We can often diagnose the problem over the phone or for more unusual problems do send us photos by email or even send us leaf samples by post and we’ll have a look under the microscope. Once you know what you’re dealing with it’ is much easier to treat the problem and get your tree back on track.