Citrus Tree

Yes! It is possible to grow lemons, limes and other citrus plants in the Pacific Northwest. Follow these simple guidelines for success:

Grow Citrus in Containers

Our climate is too cold and wet in winter for most citrus plants to survive in the ground. The simple solution is to grow them in pots. Move them outdoors in spring after frosts are no longer a threat, and back indoors in autumn before the first frost.

To transition plants between outside and inside, place them outdoors during the day and indoors at night for a week before moving the plant to its seasonal location.

Plants grown in containers grow slower because of limited root space, and will stay smaller than if they were planted in the ground. Some are grafted to dwarfing root stocks to help plants bear fruit at a younger age.

Growing Citrus Outside

Move plants outside around the average last frost date. In Portland that is mid-March, but this is an average, so pay attention to forecasts for dipping temperatures and protect plants if necessary.

While outside citrus need:

• Light: Full sun, at least 8 hours a day.
• Soil: Use high quality potting soil in containers. When potting, do not add gravel to the bottom of the pot; it raises the water table and can cause rotting in the roots.
• Water: Soil should be moist, never too soggy or too dry. Allow the top 1-2” of surface soil to dry between waterings. In hot temperatures, water more often. Wet the root ball completely, allowing the water to drain. Never allow the roots to sit in water.
• Fertilizer: Plants growing in containers rely on you for nutrients, so applying fertilizer is important. Fertilize in spring and summer only, and follow the directions for application on the container. We recommend EB Stone Citrus & Fruit Tree Food.
• If iron deficiency becomes an issue, treat with a chelated liquid iron product. Signs of iron deficiency are green leaf veins with yellowing between the veins.

Growing Citrus Inside

Move plants indoors around the average first frost date. In Portland that’s in mid-November, but it does vary. Check forecasts for freezing temperatures to be sure your plant is not damaged by cold.

Before moving the plant inside, check leaves and branches for any signs of insect activity. To prevent spread deal with any insects before bringing plants indoors. Some leaf loss is normal when plants move indoors.

Caring for Citrus while they’re indoors:

• Light: Place plants in a bright south-facing window or invest in a grow light. Use full-spectrum bulbs and be sure to turn them off at night.
• Water: In fall and winter plants require less water. Check on them once a week, but continue to allow 1-2” of surface soil to dry between waterings. Do not plants dry out entirely. When you water, wet the root ball completely and allow water to drain out before placing in a saucer. Overwatering is the primary cause of flower bud drop, fruit drop and loss of leaves.
• Fertilizer: Do not fertilize during winter months.
• Blooming: it’s very likely that flowering will occur during winter while plants are inside. This is fantastic because their flowers smell delicious! However, there aren’t many active insects to provide pollination during winter, so hand pollinating is a good idea.

Pollination

Citrus are self-fertile, so just one plant is required for pollination. You may get more fruit if you hand pollinate: use a small paint brush and move pollen from flower to flower. Dropping fruit can be a sign of poor pollination.

Pests

Citrus plants are prone to aphids, spider mites and scale. Sticky leaves, webbing on the back side of leaves, pinholes in leaves and leaf-drop are symptoms to keep an eye out for.

It’s important to correctly identify insect issues before treating so that the appropriate solution can be found. If you’re seeing symptoms, bring leaf or stem samples in to our Information Desk and we can help with diagnosis and treatment options.

• Aphids can be controlled by rinsing them off with a strong stream of water or applying insecticidal soap.

• Spider mites can be controlled by applying Mite X. The active ingredients are cottonseed & clove oilsSpider mites can be controlled by applying miticide. There are several organic miticides available.

• Scale is more difficult to deal with. Young scale bugs are mobile and are hard to see without a microscope. By the time you see them, scale bugs are adults and have laid eggs.

First, physically remove scale insects that are visible on the plant. Using a q-tip dipped in rubbing alcohol can help loosen the hard shell from stems and capture insects that may be hiding out under the shell. Consider removing entire branches if the infestation is particularly dense.

Follow up by spraying to remove invisible mobile insects. Horticultural Oil is an effective spray.

Water thoroughly before spraying and do not spray when temperatures are above 75- 80 degrees, or 24 hours before a freeze.

Monitor weekly and treat plants again if they continue to be plagued by scale.

• Sooty mildew appears when sucking insects like aphids, spider mites or scale, are present. It will go away when the insect issues are treated, or it can be wiped off with a wash cloth.