Growing lemon trees

Is it suited to your area?

Lemons are among the least cold-hardy citrus ^[2][7]. Whether one can live outdoors where you are depends mostly on winter cold. Look at each factor below on its own.

Winter cold (your hardiness zone)

Your hardiness zone describes your typical coldest winter night. It’s based only on winter lows, so it says nothing about summer heat, and it isn’t a planting calendar ^[1]. In Arizona, citrus is grown safely in zones 9b and 10a, and in zone 9a only on slopes where cold air drains away ^[2]. Oregon State describes Meyer lemon as cold-hardy only in zones 9–10 ^[3]. In Florida, most lemons do best in the central and southern parts of the state, while Meyer lemon can be grown statewide ^[10].

Winter chill

Lemons are evergreen and aren’t chosen by chill hours the way apples are. In Florida, flower buds form in late fall and trees bloom from late December into March, and lemons can flower and fruit on and off through the year ^[4].

Frost at bloom

Because lemons often bloom in winter and early spring, flowers can be open when freezes come. Flowers and young fruit are killed at about 29°F ^[4]. New leafy growth is also among the most tender parts of the tree ^[2].

Summer heat

Citrus is grown in southern Arizona’s hot low deserts, including Phoenix and Yuma, so summer heat alone isn’t a barrier ^[2]. Bark that pruning suddenly exposes to strong sun can sunburn; Arizona Extension suggests painting it with white latex paint ^[2].

Seasons of the tree

• Flowering. Mostly late winter to spring in Florida, with some flowering through the year ^[4]. Flowers and young fruit die at about 29°F ^[4].
• Fruit growth. Fruit hangs on the tree for months. Mature fruit is damaged at about 28–31°F ^[4], and Texas A&M notes citrus fruit freezes at about 26–28°F when the cold lasts several hours ^[7].
• Harvest. Lemons don’t ripen after picking. They are often picked once they reach about 1½–2 inches across and then cured indoors ^[4]. Meyer lemon ripens mainly in fall and winter ^[5][11].
• Winter. Leaves drop at about 22–24°F, and wood is badly damaged at about 20°F ^[4]. Mature Meyer lemons are hardier, around 20–22°F ^[6][5].

Several things shift these numbers. On clear, calm nights, leaves can be 3–4°F colder than the air temperature ^[7]. Trees that have had weeks of gradually cooler weather (“hardened off”) can take 5–6°F more cold than trees still growing actively ^[7][13]. Young trees and trees carrying a lot of fruit are less hardy ^[6][7], and fruit, young shoots, and young trees are the most easily hurt ^[8]. How long the cold lasts matters as much as how low it goes ^[6][7].

Cold protection

When a freeze is forecast:

• Pick full-size fruit. Citrus doesn’t ripen off the tree, so leave small fruit, but pick lemons that are ready. Taking fruit off a young tree also helps the tree itself ^[6].
• Water dry soil during the day. Bare, moist soil stores more heat and gives it off at night. Clear mulch and grass from under the tree before winter ^[6][14][8].
• Cover young or small trees. Drape a frost cloth or blanket over the whole tree so it reaches the ground, put it on before sundown, and don’t tie it around the trunk ^[6][9][5]. Keep plastic off the leaves ^[6][8]. Take the cover off the next morning once it warms above freezing ^[6].
• Add gentle heat if you like. Old-style string lights with large incandescent bulbs add warmth under a cover; small bulbs give off little heat. Keep bulbs off the leaves and fixtures dry, since hot bulbs and bad wiring can start fires ^[6][9].
• Protect the graft on young trees. Before a hard freeze, mound loose soil around the trunk above the graft union, and remove it in early spring ^[9][2]. Trunk wraps also help young trees ^[14].

Covers work best on clear, calm nights. They help much less in a windy freeze, when a cold air mass moves in ^[9].

After a freeze, wait. Don’t prune until new growth in spring or summer shows what’s alive ^[13][15][2]. Damaged fruit can be juiced if you pick it soon ^[2].

Growing in containers

A container lets you grow lemons where winters are too cold for them. Start a young tree in a pot about 15 inches wide and deep ^[10], and move up to larger pots as it grows, such as 15 and then 25 gallons ^[3]. Water when the top 1–2 inches of soil are dry, then water thoroughly ^[10][11].

On freeze nights, move the pot into a garage or other shelter. Roots in a pot get much colder than roots in the ground and can die if the soil drops much below 32°F ^[9].

Where winters bring regular freezes, bring the tree indoors before nights drop into the 40s°F ^[12]. Give it your brightest window, with at least 6 hours of direct sun if you want fruit ^[12]. Citrus grows best at about 55–85°F ^[12]. Move it back outside once temperatures stay above 50°F ^[12]. Make each move gradually over a week or two so the tree doesn’t drop its leaves ^[12][11].

Harvest

Lemons keep well on the tree, but only until a hard freeze threatens ^[6]. Pick fruit that has reached full size; lemons can be picked while still green and cured at room temperature ^[4]. Meyer lemons ripen mostly in fall and winter ^[5][11].

Pruning

Lemons need little pruning. Avoid pruning in fall, which can push tender new growth just before winter ^[2]. After cold damage, wait until spring growth shows the extent of the damage before cutting ^[13][15]. Meyer lemon’s thorns can be trimmed off at any time ^[11].

Varieties

Pick a variety for your winter cold first. In Arizona, citrus is grown outdoors safely in zones 9b and 10a ^[2]; where winters are colder, a Meyer lemon in a pot is a common choice ^[3][12].

• ‘Eureka’: nearly thornless and fruits through the year, but among the most cold-sensitive citrus ^[4][8].
• ‘Lisbon’: large and vigorous, a bit more cold- and wind-tolerant than ‘Eureka’ ^[4].
• ‘Bearss’: thornless or nearly so, very juicy, with few seeds ^[4].
• ‘Meyer’: a lemon hybrid that is hardier than true lemons, self-pollinating, and good in pots and indoors ^[5][8][12]. Zones 9–10 outdoors ^[3].
• ‘Ponderosa’: another lemon hybrid sometimes grown at home ^[4].

Common problems

Leaves, flowers, or fruit drop

What it looks like: A potted tree sheds leaves, blossoms, or small fruit, often after a move.

Likely causes: Big temperature swings, nights that are too cool, or too much or too little water ^[3].

What to do: Move the tree in or out gradually over one to two weeks, starting with a few hours at a time ^[12][11]. Check soil moisture before watering ^[11].

When to ask an expert: If the tree keeps dropping leaves weeks after you’ve fixed the move and the watering.

Cupped or yellow leaves indoors

What it looks like: Leaves curl or yellow over the winter.

Likely causes: Too much water is a common cause ^[12].

What to do: Let the top of the soil dry out between waterings ^[11].

When to ask an expert: If new leaves also yellow after you adjust watering.

Soft, dry fruit after a freeze

What it looks like: Fruit looks fine at first, then turns soft and puffy and later dry and pithy inside ^[2].

Likely causes: Fruit froze during a cold night ^[2].

What to do: Pick and juice damaged fruit soon. Leaves that are damaged but still attached keep working ^[2].

When to ask an expert: If branches as well as fruit were damaged.

Different-looking shoots after a hard freeze

What it looks like: New shoots with leaves unlike the rest of the tree, or fruit that is seedy, rough, or sour ^[2].

Likely causes: The top of the tree died, and only the rootstock is growing ^[2].

What to do: Arizona Extension advises replacing the tree in this case ^[2].

When to ask an expert: If you’re not sure whether shoots are coming from above or below the graft.

Related plants

Lime, orange, mandarin, and grapefruit are lemon’s citrus relatives. Limes are about as cold-sensitive as lemons, while mandarins and sweet oranges are generally hardier ^[2][8]. Gardenplanner gives general guidance for them for now.