How to Grow Eureka Lemon Trees

 Eureka lemon trees with yellow lemon hanging between leaves in sunlight

The Spruce / Sydney Brown

Eureka lemon trees produce an abundant crop of fruit throughout the year as well as making 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. Eureka lemon trees are toxic to animals.

Common Name Eureka lemon tree, lemon 'Garey's Eureka'
Botanical Name Citrus x limon 'Eureka'
Family Rutaceae
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
Hardiness Zones 9-11 (USDA)
Native Area California
Toxicity Toxic to dogs and cats

How to Plant Eureka Lemon Trees

When to Plant

Eureka lemon trees prefer to be planted during the spring to avoid cold or hot weather. Dig your hole just as deep and approximately twice as wide as the tree's root ball.

Selecting a Planting Site

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.

Build up a wide mound to plant the tree on top of or select a sloped position so it can receive enough water without you having to worry too much about drainage.

Spacing, Depth, and Support

Prepare a hole as deep as the root ball and about twice as wide as the root ball.

Eureka Lemon Tree Care

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.

Pollination

Lemon trees are self-pollinating, even if you plant a single tree; One blossom contains both male and female parts to allow self-pollination. To help pollination along, you can sacrifice one blossom and rub its interior on the interior of other blossoms which will transfer pollen to the right areas in the flower. When the sacrificial flower wilts, the pollen is used up.

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

Eureka Lemon Trees vs. Lisbon Lemon Trees

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.

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.

How to Grow Eureka Lemon Trees in Pots

A eureka lemon tree can grow in a pot, but it's best if the container remains outdoors when it's not being overwintered. It's a great option if you live in a cool climate, or have the right environment for a citrus tree but you only have limited space. But it's also important to realize that potted lemon trees will have more stress on their confined root systems as well as feeling more vulnerable to cold weather.

Choose a large container of any material that's at least 18-inches in diameter, with multiple drainage holes. Fill with well-draining potting soil. Container plants dry out faster than if they were in the ground and the same holds for potted lemon trees; Water twice a week or daily if the weather is extremely hot and dry.

You will still need to prune a potted tree, and monitor for dead, damaged, or sucker branches. Sucker branches tend to grow from the root next to the tree trunk of younger trees and need to be removed so they don't take nutrients away from the real branches.

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

If you want a clone of your parent eureka lemon tree, you can propagate root cuttings. Unlike some other citrus varieties, lemon trees are pretty easy to propagate from semi-hardwood cuttings. The key is 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. Here's how to propagate a lemon tree.

Harvesting Eureka Lemons

  1. With a sterile, sharp cutting tool, take a 6-inch cutting, making your cut at a 45-degree angle. The cut should be taken right below where a leaf and stem attach.
  2. Use a sharp cutting tool to remove all the leaves except for the top three leaves.
  3. Dip the bottom 2 inches of the cutting in rooting hormone.
  4. Fill a pot that's about 8 inches with equal amounts of perlite and peat moss, then water thoroughly and evenly before inserting the cutting.
  5. Make a 2-inch deep hole in the soil with your finger or a pencil and insert the cutting.
  6. Put a large clear plastic bag over the plant and close it at the bottom of the pot as best as you can with a twist tie or clip. Make a couple of small 1/2 inch to 1- inch slits at the top of the bag to let out condensation and so the plant can breathe.
  7. Put the pot in a very warm and very sunny area that reaches about 75 to 90 degrees Fahrenheit.
  8. Water lightly to keep the soil damp every three days, and make sure the soil stays well-drained.
  9. The cutting will begin to root in about two to three months.

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.

Common Pests and Plant Diseases

All lemon trees are tasty to a variety of pests and are afflicted by many diseases. Pests can include whiteflies, rust mites, mealybugs, aphids, and scale. While established adult trees usually can withstand an infestation or two, smaller, more vulnerable trees can be decimated by any one of these issues. Signs of pest issues will typically appear on the undersides of leaves or on the fruit.

To control and eliminate pests issues, begin by pruning away any dead, unhealthy, or infected areas of the tree. Treat the plant by spraying it with horticultural oil, like neem oil, diluted significantly, reapplying frequently until all signs of infection have ceased.

The most common diseases include citrus canker bacterial disease, and many different fungus diseases, including anthracnose, sooty mold, root rot, and botrytis rot (gray mold), all of which need to be treated accordingly with fungicides.

FAQ
  • Are eureka lemon trees easy to grow?

    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.

  • How long does it take to grow a eureka lemon tree?

    Lemon trees grow at a moderate rate, however, you may not see a lemon until three years after planting.

  • Can you grow a eureka lemon tree indoors?

    You can grow a lemon tree indoors, but it's best to choose a dwarf type like the 'Dwarf Meyer' lemon tree that grows to an average of 5 feet. It's also best if you have a south-facing window to give your tree loads of sunlight.