http://www.oregonlive.com/hg/index.ssf/2009/08/growing_citrus.html
'Meyer' lemon is a good choice in the Northwest.
Growing citrus
by The Oregonian
Monday August 10, 2009, 5:24 AM
With its thrilling scent and sunny fruit, citrus can be a rewarding -- and not overly difficult -- plant to grow. Here are some hints on growing this heat-loving group of plants, courtesy of "The Bountiful Container" by Rose Marie Nichols McGee and Maggie Stuckey:
In the Northwest, plant sour rather than sweet citrus, which takes a long stretch of hot weather to ripen. Meyer lemons are particularly well-suited for our milder summers.
Almost all citrus available to home gardeners is grafted onto dwarf rootstock, which keeps them 2 to 5 feet tall. Still, repot at least a couple of times over the years to reinvigorate them with fresh soil and some root pruning.
When repotting, clip off any roots circling the pot. Then take a knife and cut down the sides and bottom of the root ball. For a tree in a 24-inch container, McGee removes a full inch or more of soil and roots. Spring is best for repotting.
Check the grafting union (a diagonal slash on the trunk), and if growth appears below the graft, cut it off. These suckers will drain vigor from the top of the plant and won't produce good fruit.
After planting, mulch the soil surface with wood chips or bark mulch to help keep the roots from drying out.
Citrus trees like rich, acidic soil and are heavy feeders. Once a month, use fertilizer especially for citrus or look for one labeled for rhododendrons. If the fertilizer doesn't contain iron, supplement with chelated or micronized iron. Yellow leaves, especially along the veins, indicate iron deficiency. McGee also gives her citrus a shot of fish emulsion or liquid seaweed "if things are looking shaggy."
Only two pests bother citrus: spider mites and scale. If ants crawl on or near your citrus, look for scale. (Ants feast on the sweet substance exuded by the scale insects.) Use a cotton ball soaked in alcohol to clean off the scale, which like to hide on the underside of leaves. After a week, check the plant again.
For spider mites, which can cause stippling or mottling of the leaves, mist the plant with water every two to three days.
Plants can stay outside until temperatures start to go below freezing. If it looks like the mercury will drop to 33 or 34 for just one night, throw a tablecloth or sheet over the citrus. McGee brings hers indoors around December or January for several weeks and then returns it outdoors.
-- HGNW staff
