Winter Care for Potted Citrus and Meyer Lemons Indoors

Give indoor citrus at least 6 hours of direct sun, days of 65 to 75 degrees F and nights of 55 to 65 degrees F, and water when the soil is dry 2 inches do...

Published by ThriveThyme

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The Short Answer

Potted citrus can spend winter indoors and still fruit if you get a few things right:

  1. Light. At least 6 hours of direct sun a day, and 8 to 12 is better. A south-facing window is usually best, and a grow light helps when that is not enough (University of Maryland Extension).
  2. Temperature. About 65 to 75°F in the day and 55 to 65°F at night (Maryland). Keep it away from heater vents (Oregon State Extension).
  3. Water. Check once or twice a week and water when the soil is dry 2 inches down (Maryland). Water less often than in summer (Oregon State).
  4. Pollination. Indoors, move pollen from flower to flower with a small dry paintbrush (Maryland, Oregon State).
  5. No winter fertilizer. Feed in spring and summer, and stop by early fall (Maryland).

When to Bring It In

Most citrus is damaged below 32°F, so winter protection is a must (Maryland). Maryland says to bring the plant in before the first fall frost. Oregon State gives Halloween as a rough target in Oregon, with plants going back outside around mid-April. Meyer lemons are only cold hardy in Zones 9 and 10 (Oregon State).

Make the move gradually. Sudden temperature changes can cause leaves, flowers, and fruit to drop (Oregon State). Maryland notes that leaf drop often happens right after citrus comes indoors as it adjusts to new light and humidity.

Clean up pests before the move. Oregon State suggests washing the leaves. Maryland says you can spray horticultural oil or insecticidal soap labeled for houseplants.

Light

Light is what limits indoor citrus the most. Maryland calls for at least 6 hours of direct sun, with 8 to 12 preferred, and says a fluorescent or LED grow light will be needed if the window is not enough. Oregon State notes that cloudy, low light winters often call for extra lighting to get fruit to set.

Temperature and Humidity

Maryland recommends 65 to 75°F days and 55 to 65°F nights. Cooler temperatures help start flower buds. Oregon State suggests nights around 65°F for Meyer lemons and warns against blasts of hot air from heater vents. Nights that are too cool or big temperature swings can lead to dropped leaves, flowers, and fruit (Oregon State).

Citrus does not like dry winter air. Maryland suggests a humidifier near the plant set to about 50 percent humidity. Oregon State mentions a pebble tray or occasional misting.

Watering

Citrus likes steady moisture but not soggy soil (Maryland). Indoors, the bigger risk is too much water.

Maryland gives two quick signs: dropping leaves point to overwatering, and dropping flowers point to soil that is too dry.

Hand Pollinating Winter Flowers

Most dwarf citrus, including Meyer lemons, is self-fertile, so one plant is enough (Maryland, Oregon State). Outdoors, insects do the work. Indoors there are no insects, so you have to move the pollen. Use a small dry paintbrush to pick up pollen from one flower and brush it onto the next (Maryland).

Do not panic if young fruit falls. Potted plants usually set more fruit than they can carry, and Maryland says up to 75 percent of fruit may drop. Meyer lemons ripen mostly from fall to winter, and some citrus takes six to nine months to ripen (Maryland).

Fertilizer and Pruning

Feed only while the plant is actively growing, from spring to late summer. Maryland suggests a fertilizer with a 2-1-1 or 3-1-1 ratio, or one labeled for citrus, and says to stop by early fall. You do not need to feed in winter.

Winter is a fine time to prune. Maryland says you can prune from the time the plant comes in until new growth starts in spring. Remove dead, damaged, and crossing branches, and cut off suckers from below the graft. Keep in mind that pruning timing affects flowers and fruit.

Winter Pests

Indoor citrus often gets scale, spider mites, mealybugs, whiteflies, and aphids (Maryland). Watch for:

Scale is the hardest to control. Maryland suggests checking often so you catch it early. Oregon State adds crushing single insects or spot treating with rubbing alcohol when numbers are small.

Yellow Leaves With Green Veins

Maryland says this pattern usually means the soil is not acidic enough or the plant is short on iron. A soil acidifier with sulfur or a fertilizer with chelated iron can help. Follow the label for potted plants.

Next Steps

Sources