Lemons

If you live in a hot, sunny place growing lemons is a no-brainer.

Native to Asia (we think), lemons evolved out of a cross between bitter orange and citron during the times of Ancient Rome. Lemons did not become popular until they were introduced to Persia and Egypt around 700 AD. Christopher Columbus brought lemon seeds to Hispaniola (modern day Haiti and Dominican Republic), but lemon trees were seen as medicinal and ornamental plants at that time. Though they didn’t know about Vitamin C back then, James Lind discovered that adding lemon juice to the diet prevented scurvy in 1747.

Lemon leaves, blossom, and fruit (Elena Chochkova) CC BY-SA 4.0

Lemon fruits

Lemons are a type of fruit called hesperidium. Hesperidium are berries with a leathery skin and fruit that forms in sections, called carpels. Within each carpel are hundreds of juice-filled sacs, called vesicles. Lemons contain citric acid, which is what makes them taste sour. Lemons are only a little more sour than limes, but they can be almost twice as sour as grapefruits, with five times the bite found in orange juice.

The lemon tree

Lemon trees (Citrus limon) are evergreen, which means the leaves stay green all year. They do not, however, handle cold temperatures very well. Mature trees can handle occasional light frosts, but young trees need protection in temperatures below 45°F. Lemon leaves and fruit both have waxy coatings that reduce moisture loss. You can grow a lemon tree in a sunny spot in your yard, in a container, or even on a balcony. The blossoms smell heavenly!

Lemon flowers (Jon Sullivan) Public Domain

Lemon varieties

Most grocery store lemons are ‘Eureka’ lemons. This variety is also known as ‘Four Seasons’ because of its continuous production. This is also the most commonly available variety as bare root stock. There is also a pink-skinned variety of ‘Eureka’ that features green and yellow variegated skin. Thinner skinned and seedless “Bonnie Brae’ is grown in San Diego County, CA. If you want to make your own limoncello (lemon liquor), you will want to plant a ‘ ‘Femminello St. Teresa’, also known as ‘Sorrento’ lemons.

Contrary to popular opinion, ‘Meyer’ lemons are actually a cross between citron and a mandarin/pomelo hybrid. Other lemons-that-are-not-lemons include:

• Flat lemons - a mandarin hybrid
• Ponderosa lemon - a citron and pomelo cross
• Rough lemon - a citron and mandarine cross; often used as root stock

Caring for a lemon tree

Lemon trees are relatively trouble free, when grown in an appropriate location. Lemon pruning is normally limited to the standards of removing dead, diseased, and crossing branches. You will also want to remove vertical water shoots. Lemon tree trunks and the upper surface of exposed branches benefit from whitewashing, to prevent sun scald. Regular feeding will help your lemon tree stay healthy and productive. Each of the dosages listed below should be divided into 2 or 3 separate feedings:
    1st year - 3 tablespoons of nitrogen per tree
    2nd year - 1/4 pound of nitrogen per tree
    3rd year - 1/2 pound nitrogen per tree
    4th year - 3/4 pound nitrogen per tree
    5th year and on - 1 pound nitrogen per tree

Understand that 1/4 pound of nitrogen is not the same thing as 1/4 pound of packaged fertilizer. Assume, for example, that your 5 pound bag of fertilizer has an NPK of 10-5-2. This means that out of the 5 pounds, 10% of the bag is nitrogen, 5% is phosphorus, and 2% is potassium. [The rest is filler.] This works out to 1/2 a pound of nitrogen, a 1/4 pound of phosphorus, and 1/10 of a pound of potassium. In all likelihood, your lemon tree will not need those other nutrients, so they are best left out of the equation (especially until after you get a soil test). An easier way to feed your lemon and other citrus trees is to use blood meal or ammonium sulfate.

Blood meal contains 13.25% nitrogen, 1% phosphorus, and 0.6% potassium. To equal one pound of nitrogen, you would need to apply 7-1/2 pounds of blood meal. Five pounds of ammonium sulfate will give you the same amount of nitrogen. Just remember that these feedings are totals for the year and that they should be spread out over three different feedings, ideally in April, June, and August. Lemon trees also benefit from a top dressing of aged compost.

Lemon pests and diseases

The biggest insect threat to your lemon tree (and lemon trees across the country) is the Asian citrus psyllid, which can infect your tree with a fatal disease called huanglongbing, or HLB, for short. Leaf miners will burrow tunnels in citrus leaves, but the damage is mostly cosmetic, unless it becomes extensive. Other lemon pests include aphids, katydids, citrus cutworms, several varieties of mites, mealybugs, glassy-winged sharpshooters, Fuller rose beetles, hoopla beetles, leafrollers, snails, thrips, whiteflies, and nematodes. Several varieties of scale insects are attracted to lemon trees, including, black scale, brown soft scale, California red scale, citricola scale, cottony cushion scale, and purple scale. Lemon tree diseases include alternaria rot, armillaria root rot, anthracnose, brown rot, citrus blast, exocortis, phytophthora-related diseases, and the Tristeza disease complex.

Like other citrus trees, many lemon trees will follow an abundant year with a year of reduced production. This does not mean that anything is wrong.

Lemons are very easy to grow and they can produce an astounding amount of fruit. Get yours today!