growing and caring for citrus indoors

I have a Eustis limequat, and it’s producing flowers. Should I be taking a brush and dusting pollen from one bloom to the other? Also, I’m growing it inside. Do I need any additional lighting? I have fluorescent lights as well as full-spectrum UVA/UVB lights that I can use. Someone told me I’d need to get really pricy calcium lights, or something similar.

All the resources I’ve found suggest that citrus flowers are self-pollinating with a very few exceptions. However, your limequat (x Citrofortunella floridana) is growing indoors, so pollination assistance from you will help. Alabama Cooperative Extension, in a publication no longer available online, describes citrus as generally self-fruitful.

Excerpt:
“With the exception of Clementine tangerine and certain tangerine hybrids such as Orlando tangelo, citrus trees are self-fruitful and do not require cross-pollination. Thus, self-fruitful types of citrus can be grown as single trees. Cross-pollination requires that two or more varieties bloom at the same time. Some varieties will not cross-pollinate each other. Satsuma and navel do not produce viable pollen and thus cannot be used for that purpose.”

I looked at several of our books on growing citrus to see if they mentioned any special lighting needs, and Success with Citrus Fruits by Sigrid Hansen-Catania (Merehurst, 1998) simply says that your artificial light source needs to provide 12 hours of light a day, if you do not have a position for the plant near a sunny window. She mentions “specially adapted fluorescent tubes which you can fix to the ceiling about 8-16 inches above the plants,” though she mentions it in the context of providing adequate light during winter months.

University of Missouri Extension has a general article on indoor lighting for plants.

Here is an excerpt from an article (no longer available) from Purdue University Horticulture specific to citrus: “Citrus foliage can adapt to the relatively low light levels typical of our homes. However, if flowers and fruit are what you’re after, you’ll need to give the plants as much light as possible. If natural light is inadequate, you can supplement with artificial lights. A combination of cool white and warm white florescent lights placed close to the plants will help, as will the special ‘grow lights’ that emit the wavelengths of light most important for plant growth. (…)

If citrus is kept indoors year-round, the plants will likely need a bit of pollination assistance when they do flower. Use an artist’s paintbrush or cotton swab to transfer pollen from one flower to another.”

The good news is that I don’t think you need to invest in any additional expensive lighting systems!

on growing tea plants

I am interested in growing tea plants. In particular, I am interested in these: Cyclopia intermedia (honeybush), Aspalathus linearis (rooibos), and Citrus aurantium (bergamot). Also, do you know which local nurseries might sell these plants?

For the first two plants, I consulted Cape Plants by Peter Goldblatt and John Manning (Missouri Botanical Garden, 2000). Cyclopia intermedia and other Cyclopia species (Honeybush) grow in southeast and southwest Africa in what is called “mountain fynbos” regions. The climate is similar to that of Mediterranean areas, so if your climate has wet winters and dry summers, there is a chance you may be able to grow this plant. The South African Honeybush Tea Association has more information about this plant as a source of tea.

Aspalathus linearis, or Rooibos, is found in South Africa from the Bokkeveld Mountains to the Cape Peninsula. The website PlantzAfrica has information about it that suggests it is not often grown in home gardens: “This is thought to be due to the difficulty in propagation by seed or root cuttings and in providing the optimal growing conditions for the plants. In order to grow Aspalathus linearis successfully, seeds must first be scarified and then planted in acid, sandy soils.” The Plants for a Future Database suggests that this plant would not grow with much success in a colder, wet winter climate.

The bergamot which is used to flavor Earl Grey tea goes by the botanical names Citrus aurantium, C. aurantium subspecies or variety bergamia, and Citrus bergamia. According to Purdue University’s New Crops web page, this tree is a native of Southeast Asia: “The sour orange flourishes in subtropical, near-tropical climates, yet it can stand several degrees of frost for short periods. Generally it has considerable tolerance of adverse conditions. But the Bergamot orange is very sensitive to wind and extremes of drought or moisture.” See also the following from University of California, Riverside’s Citrus Variety pages. The tree grows well in Italy and North Africa, but it may not do very well in the Pacific Northwest.

Of these three plants, the only one for which I found a nursery source (in California, not locally) on Plant Information Online was the bergamot Citrus. You may want to call your favorite local nurseries to ask if they ever carry this plant, but I suspect that most will not, as it is not likely to succeed in our climate. You might have better luck growing familiar herbs like chamomile and mint which can be used for tea. You could also make green, black, and oolong tea from the leaves of Camellia sinensis, a plant which will thrive here in Seattle, and should not be too difficult to find. According to Keith Possee, who manages the UW Medicinal Herb Garden, offers the following advice:
“The trick is to pick only two leaves and a bud in the spring flush of growth. If we lived in the tropics, home tea growers could be picking tea most or all of the year, but 48 degrees north latitude is not ideal.” The most important step to learn is how to roll the leaves. Keith recommends this University of Hawaii Extension document entitled Home-Processing Black and Green Tea by Dwight Sato, et al.

Nagami kumquat hardiness

I live in Redmond, WA and I recently noticed that we have been classified as Zone 8A – 8B instead of 7B. Most sources I read state that year-round outdoor planting for Nagami kumquats is recommended only for Zone 8 and above. What is your take on this? I’ve had a Nagami since November, but it has acted differently from what sources I read indicated. I also have a Meyer Lemon that I bring indoors and it did fine over the winter, but the Nagami shed all its leaves within 2 months starting from January. The peculiar thing was that the leaves shed were all green and healthy, leading me to believe it had entered dormancy. It started to grow new leaves in April, but I’m still puzzled why it entered dormancy in indoor conditions even though the less cold-tolerant Meyer flourished.

Long story short, if the Nagami sheds its leaves every winter, will it ever have enough time to produce mature fruit even if it did survive outside?

If you have any particular kumquat or citrus experts you could recommend, that’d be great! Thanks!

According to a local nursery (Raintree), the Nagami kumquat is hardy to 18 degrees, and may produce fruit here. So if we have a cold snap, as we occasionally do, it may be hard on the tree if it’s growing outdoors–unless you can provide it with protection. A friend of mine has grown kumquats before, and they produced fruit, but I believe a long period of subfreezing temperature killed her tree one winter/early spring.

Growing Citrus by Martin Page (Timber Press, 2008) says that kumquats (Fortunella japonica or synonymously Citrus japonica) are prone to zinc deficiency which results in smaller leaves and shorter shoots. They are considered very hardy, but this may be “due to their long winter dormancy.” Nagami grown in a pot will reach about 4 feet, but outside, it can get to 13 feet tall. Fruit is harvested October to January.

It’s possible your Nagami kumquat dropped its leaves because it was entering dormancy, but there are other causes to consider as well. According to the source cited above, leaf drop in citrus trees can be caused by:

sudden environmental changes (temperature, humidity, etc.)–bringing a plant inside to overwinter is likely to expose it to dry air
underwatering (don’t overcompensate by watering a leafless plant because it has no way of transpiring the water without its leaves; prune it the next spring by reducing shoots by about a third of their length)
overwatering (make sure container drains well; soil that doesn’t drain well can lead to yellowing leaves and leaf drop)

You may want to speak to a local expert at the Western Cascade Fruit Society, or the Home Orchard Society.

Also the nurseries that specialize in fruit trees are good resources:
Raintree

Cloud Mountain Farm

Burnt Ridge

Meyer Lemon tree care guidelines

I did not feed my Meyer lemon plant this summer. The leaves
are light green. Should I feed it before I bring it inside for the
winter or wait until mid-winter?

The pale leaves make me think perhaps there is a nutrient imbalance or
deficiency, but it would be hard to say precisely via e-mail. Pale leaves
might also mean lack of exposure to sunlight. Are the pale green leaves
newer or older leaves? According to the University of Santa Cruz Center for Agroecology, a nitrogen deficiency would be evident if older leaves
lower down on the tree were turning yellow.

According to the book Citrus by Lance Walheim (Ironwood Press, 1996),
nitrogen is the only nutrient which citrus plants need on a regular
basis, and Meyer lemon needs less than other lemon species. A lot depends
on your soil. If the soil is alkaline, this may “tie up” micronutrients
and keep them from being absorbed by the tree. You might want to take
samples of the leaves and soil to your local county extension agent.

The Walheim book offers the following advice on growing citrus in
cold-winter climates:

Make slow transitions from indoors to outdoors and back…The transition
period should last at least three to four weeks. Before bringing the
plant indoors, move it to a location where it receives less direct
sunlight. Gradually decrease exposure to the sun. Unless you’ll be
keeping the plant in a cool location, don’t wait to move plants after the
weather has become cold and your heater is on indoors. ..Just before
moving a plant indoors, hose it off to clean the foliage…

The conditions found in most homes in winter–low light and warm, dry
air–will cause many citrus trees to turn yellow and drop their leaves
and fruit…To prevent his, place the trees in a cool, well-lit location
and try to maintain high humidity. A cool greenhouse, where temperatures
stay above freezing, is ideal…To increase humidity…place the tree on
a large tray covered with rocks and filled with water. Replace the water
as it evaporates.

General indoor care guidelines, also from the Walheim book:

Do not overwater. Let soil dry out partially between waterings.

Fertilize lightly. About 3-4 weeks before taking trees back outside,
increase fertilizer.

So I don’t think you need to fertilize the tree
before you bring it inside. Here is a link to a question from our library’s database, with details on fertilizing Meyer lemon.

Check often for signs of insects.