Lemon trees are one of our favourite garden plants, yet one that seem to give us more trouble than most. Poor crops of fruit, fruit dropping before it ripens, and pale, sickly foliage are just some of the problems that are commonly encountered with backyard lemons.
Most people would agree they’re worth persevering with though. A healthy tree in the right position will reward you with abundant tangy fruit for many months of the year.
Which is the Best Lemon to Grow?
Choosing the right variety for your needs and your growing conditions is part of the secret of growing good lemons. Meyer, Lisbon and Eureka are the common choices, and they are all bear good fruit. Some people grow seedlings, but characteristics including cold tolerance and fruit production will be uncertain on a seed grown plant. The most important differences between varieties are taste of the fruit, the size of the tree, their tolerance to frost, and the time they bear fruit.
Meyer is a popular choice for home gardeners. The fruit is very juicy and has a sweeter (less acid) flavour than the other lemons. The tree is smaller and more compact, and is more tolerant of cool conditions.
Lisbon is a large, vigorous tree that bears large crops of fruit. The old varieties were very thorny, but newer, less thorny strains are now available. It is more tolerant of frost than Eureka.
Eureka is less vigorous and has fewer thorns. It grows well in mild climates and bears most of its crop in summer when the other varieties aren’t bearing fruit.
Winter is the main cropping period for all lemon varieties, but in frost-free areas trees can bear fruit practically all year. Eureka is especially useful for producing fruit in summer.
Learn more about growing Citrus Fruit here
Getting your Lemon Trees off to a Good Start
It takes a lot of work to get a sickly tree back into good health so it makes good sense to avoid this happening in the first place.
1. Choose a healthy specimen at the nursery
When you buy a lemon tree, look for the following:
- a straight, sturdy stem
- leaves are free of blemishes, and any obvious signs of pests or diseases
- leaves are glossy, dark green and turgid (not wilting)
- roots are not growing through the base of the pot
- the bud union (ie. the swollen joint on the stem where the tree has been grafted) has completely healed over
- the potting mix is free of weeds
2. Plant the tree at the right time in the right position
Lemon trees can be planted at any time in frost-free areas. In colder areas, they should be planted in mid to late spring, after the frosts have finished; or grown as a tub plant; protected over winter.
Choose a sunny position, protected from strong wind. The soil should be friable and well-drained. In heavy, clay soils, plant the tree on a raised mound. Where possible add plenty of well-rotted compost to the soil. The soil should ideally have a slightly acidic pH (ideally around 5.5 to 6.5).
How to plant the lemon tree
Dig a hole around twice the width of the pot and about one and an half times as deep. Remove the tree from the pot and gently tease out the roots. Trim off any broken roots with secateurs. Place the tree in the centre of the hole, making sure the tree is planted at the same depth as it was in the pot.
Backfill with soil, gently firm it down, and water in thoroughly. Apply a slow-release fertiliser, and cover the soil with a layer of mulch, making sure the mulch is kept clear of the trunk, otherwise stem rot may occur.
Caring for your Lemon Tree
Lemon trees are shallow rooted so take care not to disturb the roots when digging around the base. Lemon trees require plenty of nitrogen – apply blood and bone or a specially formulated citrus fertiliser which contains about 10% nitrogen in early spring and again in late summer. Well-rotted manure will also help the tree to grow well.
Keep the tree well watered (but not over watered) during spring and summer. A drip irrigation system will help to supply an even supply of water, and a good layer of mulch will help to conserve soil moisture and prevent weed growth.
Most lemon trees do not need pruning unless they become too tall – simply cut back the branches to keep them at a manageable height.
Live in a Temperate Climate?
Find out about other fruit you can grow here
Find out about other fruit you can grow here
What Can Go Wrong
- Temperature. Most lemons only do well if the temperature doesn’t drop below around 3 degrees C. Given that temperature a metre or two above the ground is higher than at ground level; some trees may perform well if protected until the canopy gains some height. Otherwise, they are best grown in tubs and moved under cover in the coldest months.
- Fruit drop. This often occurs as a result of uneven watering, especially when the young fruits are developing. Keep the tree well watered throughout spring and summer to avoid this problem. Also take care when fertilising – too little or too much can aggravate the problem.
- Fruit not forming. There are a number of causes including wet or dry weather, frost damage and insect attack at flowering time.
- Dry fruit. Fruit which is left on the tree too long sometimes become dry and lacking in juice. Long periods of cold weather can also cause developing fruit to dry out.
- Pale green, spindly foliage. Nitrogen deficiency is the main cause of pale foliage – apply a nitrogenous fertiliser.
- Yellowing leaves and bark splitting on the trunk. This is caused by collar rot disease – preventative measures include improving drainage, keeping mulch away from the trunk and choosing plants budded onto resistant rootstocks (eg. Trifoliata and Citrange).
- Warts on fruit. This is caused by citrus scab, a fungal disease which occurs at flowering time in wet weather. It is more common in coastal areas. Spray with white oil at flowering time.
- Swellings on stems. This is most likely caused by the larvae of the citrus gall wasp. If left untreated the tree may die within a couple of seasons. Cut off and burn all affected branches as soon as the problem is detected.
- Bug infestations. The most common bug is the bronze orange bug which feeds on the sap of young shoots, causing them to wilt. If these are not controlled, fruit production is likely to suffer.
- Black soot on foliage and stems. This is caused by sooty mould fungus, which grows on the honeydew secreted by some insects such as scale. Control the insects to stop the sooty mould.
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