How to Grow Eureka Lemon Trees

 Eureka lemon trees with yellow lemon hanging between leaves in sunlight

The Spruce / Sydney Brown

The juicy, tangy, sour fruit from the Eureka lemon tree (Citrus x limon 'Eureka') is sold commercially around the globe alongside the Lisbon variety. Although similar in look and taste, they do have several distinct differences.

Eurekas don't have such a prominent mammilla (protruding nipple), and their skin is more textured. Eureka lemon trees don't have the thorns you find on the Lisbon type, but, they aren't quite as cold tolerant, and need to be moved indoors if there's even the slightest sign of frost. Eurekas also have a more spreading growth habit and open form, while Lisbon lemon trees are more upright and their fruit grows inside the dense canopy of the tree as opposed to the outside.

As well as producing an abundant crop of fruit throughout the year, Eureka lemon trees make an attractive garden addition. The foliage turns from a bronze shade to a bright green when established, and their white blooms are fragrant, pretty, and have a purple-tinged bud. They can be planted throughout the year in warm climates and reach maturity within three years. If you plan to overwinter them indoors, plant them in the spring after any danger of frost has passed.

Botanical Name Citrus x limon 'Eureka'
Common Name Eureka lemon tree, lemon 'Garey's Eureka'
Plant Type Evergreen tree
Mature Size Up to 20 ft. tall
Sun Exposure Full sun, partial shade
Soil Type Loamy, sandy, clay
Soil pH Well-drained, moist
Bloom Time Spring
Flower Color White
Hardiness Zones 9-11, USDA
Native Area California
Toxicity Toxic to dogs and cats

How to Plant Eureka Lemon Trees

Lemon trees are particularly sensitive to cold weather conditions. The trees really need a warm and sheltered position to thrive.

Because they like a lot of water, it isn't recommended to plant your Eureka lemon tree directly into a flat lawn, especially if there are drainage issues. Not only will the surrounding grass not appreciate so much water, but the tree could get oversaturated.

Building up a wide mound to plant the tree on top of, or selecting a sloped position will mean it can still receive enough water without you having to worry so much about drainage.

Eureka Lemon Tree Care

Growing your own Eureka lemon tree isn't too tricky if you live in a hot Mediterranean-type region where it can get plenty of sun in well-drained soil--it is native to California. Even if temperatures dip in winter, because these trees do well in a dwarf form in containers, they can easily be moved indoors for overwintering.

Light

Access to plenty of sunlight is a must for Eureka lemon trees—ideally, at least 10 hours a day. Although they can cope in a partial shade location, they won't produce an abundant harvest, and their growth rate will slow significantly.

Soil

You'll need well-drained soil for your Eureka lemon tree. Preferably it'll be loamy or sandy, and they thrive in acidic conditions.

Water

Eureka lemon trees are more water-hungry than the Lisbon variety. Ensuring the soil is kept consistently moist is recommended. In the summer, you may need to water the tree every day.

Don't be tempted to mulch around the tree as this can result in waterlogging. Although these trees like to be kept moist, they can't stand saturated conditions or standing water.

Temperature and Humidity

Well-suited to Mediterranean-style climates, Eureka lemon trees aren't a cold-tolerant species. If temperatures reach as low as 20 degrees Fahrenheit, your tree will likely not survive outside. They also don't cope well with harsh winds and need a sheltered location.

When the temperatures drop, container-grown trees should be moved indoors to a warm and sunny spot until the return of warmer temperatures.

If your house is very hot and suffers from dry air, using a humidifier can help to ensure the tree receives enough moisture and remains healthy and fruiting.

Their preference is to be kept in temperatures of around 75 degrees Fahrenheit or above for year-round fruiting, although increased cold hardiness does develop as they mature.

Fertilizer

Heavily fruiting trees like the Eureka use up a lot of energy and are always hungry as a result. They appreciate organic matter being added to their soil and having a bi-annual feed with fertilizer that is specifically designed for citrus trees.

Lemon tree with yellow lemons hanging from branches in sunlight closeup
The Spruce / Sydney Brown
Lemon tree branch with a yellow lemon hanging in middle of leaves closeup
The Spruce / Sydney Brown
Lemon tree with yellow lemons and winding trunk in between green foliage and awning with purple flowers on top
The Spruce / Sydney Brown

Harvesting Eureka Lemons

It can take at least three years before your tree is fully established and ready to produce a healthy crop. If you do spot any random flowering in advance of this, it can be a good idea to remove them to allow all the energy to be conserved to support appropriate early growth.

This type of lemon tree is known for producing a good crop throughout the year when the conditions are right.

As with all citrus fruit varieties, the Eureka lemon won't ripen off the tree. It should remain there until soft to the touch and fully ripened and ready to use.

Pruning

Because of their open-spreading habit, Eureka lemon trees won't need pruning regularly the way the upright Lisbon variety will. It'll just be a case of trimming away diseased, damaged, or overcrowded sections. This can be done at any time of the year on an evergreen tree like this.

Over the years, Eureka lemon trees can reach up to 20 feet in height. If you want to keep them more compact, pruning may be more of a necessity.

Propagating Eureka Lemon Trees

Unlike some other citrus varieties, lemon trees are pretty easy to propagate from semi-hardwood cuttings. Be sure to select healthy, new growth during the late spring or early summer and cut a section that doesn't have any flowers or fruit on it.

Make sure the cuttings are kept in a moist but well-drained medium in warm conditions while waiting for them to root.

Overwintering

This type of lemon tree is generally best overwintered indoors unless you have particularly mild winters. They are not known for their frost tolerance and they don't take well to the soggy conditions that can be created by mulching.

Make sure you position them in a warm, bright spot if you want to continue to be able to produce a good fruit harvest. Be careful temperatures are not overly hot, though, as those that mimic those of early spring can encourage a more abundant bloom.