Lance Walheim might be just about the smartest guy around when it comes to growing citrus in gardens.
Lance is a professional citrus grower, co-founder of California Citrus Specialties, a commercial grower of dozens of citrus, including many lesser-known varieties. He is a UC Berkeley graduate with a degree in botany and the author of over 30 gardening books, including the definitive book "Citrus, A Complete Guide to Selecting and Growing Over 100 Varieties." Lance was staff editor at Sunset magazine for several years and served as contributing editor to the 10th, 11th, 12th and 13th editions of the "Sunset Western Garden Book," as well as the 14th edition, now in process.
For several years I've listened to Lance patiently instruct countless home gardeners on everything citrus, from the best varieties, to methods of planting, fertilizing, pest control, pruning, soil and so on.
Perhaps the two points that I hear Lance emphasizing the most are the importance of the correct variety for each person's unique climate and the importance of choosing citrus varieties that will provide the owner with fruit over a long period, not all at once.
Although almost any variety of citrus will grow and flourish wonderfully in just about any Orange County garden, a particular variety may not taste the same in every garden. A variety planted in a Huntington Beach garden may not have the same flavor and sweetness as the same variety just 20 miles away in Anaheim Hills.
Don't choose a citrus variety for your garden because of the flavor of the fruit in the supermarket; it's a huge mistake. Citrus flavor is strongly influenced by climate, especially in oranges, tangerines (also called mandarins) and grapefruits. The amount of a hot, dry summer may make the fruit sweet in one garden yet sour in another.
The other lesson that Lance always encourages is to select citrus varieties that ripen in succession, or at least in alternate seasons. For instance, why have four varieties of tangerines that all ripen at Christmas and then none to pick at other times of the year? Instead, with just a little planning and knowledge, then the right varieties, you can pick sweet, juicy tangerines over at least half the year.
Looking for year-round oranges from your garden? The Cara Cara Navel, Lane Late Navel, and Midknight Seedless Valencia all feature sweet, juicy fruit that are seedless or nearly so. The Cara Cara ripens from winter through early spring, followed by the Lane Late Navel in the spring to the beginning of summer. Then, the Midknight Valencia takes over from early summer through fall. Without much effort you could have fresh oranges in your garden just about every month of the year.
Add to that an Owari Satsuma mandarin, which ripens in November and December, and you can be picking fresh, tasty citrus all year. Try to do that with peaches, plums, apricots or any other fruit.
Dwarf and semi-dwarf citrus can be grown in large containers on a sunny patio, but in my experience the soil is of utmost importance. In pots plant citrus using "cactus mix" — don't worry, citrus can't read. Citrus will love this faster-draining, leaner soil mix. If you can't find cactus mix you can add about one-third decomposed granite, pumice or No. 16 silica sand to a quality all-purpose potting soil and end up with a very good soil for potted citrus. Regardless of the soil you use, it will decompose over time. Either repot or change the soil in your citrus containers every two or three years. You don't necessarily need to go to a larger pot, so long as the roots aren't crowded or circling in the pot.
Speaking of circling roots, when shopping at the nursery it's not always best to pick out the largest citrus in the row. Citrus have a strong tap root as well as traditional branched roots. If the roots have reached the side of the plastic nursery pot, turned and begun growing in a circular manner it may never perform well in your garden. Contrary to your intuition, a smaller citrus that is not rootbound will almost always outperform its larger relative.
Finally, citrus are heavy users of fertilizer. But not just any fertilizer. Citrus need plenty of nitrogen and they need it frequently, especially if they are growing in pots. They also need unusual quantities of iron, zinc and manganese, nutrients that are missing in most fertilizers. Pale, yellow, weak citrus are a common sight around Orange County. Although other factors are sometimes the cause, quite often they just need more fertilizer — the right fertilizer.
Citrus are the most popular fruit grown in Southern California gardens, by a long margin. I can almost hear Lance now, explaining once again to an attentive group of citrus students. He's discussing how important it is to select the right variety for your climate, then the importance of choosing varieties that ripen at different seasons. Thanks Lance, we're listening.
RON VANDERHOFF is the nursery manager at Roger's Gardens, Corona del Mar.
Question: I'm thinking of collecting some of the rainwater that falls on my roof and runs down my gutters. Is this safe to use on my potted plants?
Grace, Laguna Beach
Answer: It's like Dom Pérignon champagne to your potted plants. Yes, yes, yes, rainwater is the best source of water your plants could ever receive. It's clean, full of oxygen and your plants will love it. If it hasn't rained in a while and the roof is dirty, I usually let the first hour or so of rain clean things off a bit, then I start the harvest.
ASK RON your toughest gardening questions, and the expert nursery staff at Roger's Gardens will come up with an answer. Please include your name, phone number and city, and limit queries to 30 words or fewer. E-mail email@example.com, or write to Plant Talk at Roger's Gardens, 2301 San Joaquin Hills Road, Corona del Mar, CA 92625.Copyright © 2015, Los Angeles Times