- Author: Rich Zimmerman
The Meyer Lemon, Citrus x meyeri ‘Improved’, is a colorful presence in the winter garden. The tree’s green foliage punctuated with oblong orange-yellow fruit fits easily into holiday season decorations.
The Meyer lemon was introduced to the United States in 1908 by a U.S. Department of Agriculture plant explorer named Frank Meyer. He found the plant, a hybrid cross between a lemon and an orange near Beijing, China. The Meyer lemon was quickly introduced as a home orchard and container tree and sold primarily in the western United States. Unfortunately most of the Meyer lemon trees cloned until the early 1970’s were symptomless carriers of the Citrus tristeza virus (Closterovirus genus) a virus which causes decline, stem pitting and seedling yellows in citrus species and threatened the California citrus industry. This prompted regulations by the California Department of Food and Agriculture and the US Department of Agriculture to destroy most existing Meyer lemons. Fortunately, Don Dillon, a nurseryman, at Westwind Nurseries in Fremont California found a virus-free specimen that was subsequently certified and released by the University of California in 1972. All current Meyer lemons are derived from this virus free budwood and are sold as the Improved Meyer lemon, Citrus x myeri ‘Improved’.
The Meyer lemon is a thornless, shrubby, semi-dwarf plant well suited for container gardening. It can grow to six feet in containers but can be kept shorter by pruning. The usual rootstock is the Yuma Ponderosa lemon. The tree flowers intermittently during the year, providing lemons year-round although the heaviest set is in the spring. The blossoms are purple tinged and highly aromatic. The tree has cold and heat resistance comparable to sweet oranges and can be grown over a wider range than standard lemons or limes. It is hardy to 28 oF and can withstand short intervals of even colder temperatures.
The fruit is medium sized, oblong to elliptical with a thin, smooth, fragrant and tightly adherent yellow-orange rind. The fruit will self-store on the tree and the rind will become a deeper orange with time. The flesh is yellow to a light orange-yellow and very juicy with numerous seeds. The aroma and flavor of the Meyer Lemon is distinctive and the juice slightly acidic. The fruit has ben promoted as a ingredient in California cuisine by numerous chefs including Alice Waters. Its distinctive flavor has been added to salads, glazes, desserts and even bread. The ripe fruit is too tender and juicy to be successful as a commercial variety without significant loss during handling and shipment. The primary source of Meyer lemons for culinary use is from home-grown trees making the improved Meyer lemon one of the most widely grown home citrus varieties for both its fruit and ornamental beauty.
Try growing a Meyer lemon if you are looking for a productive, decorative tree that is relatively easy to care for. Meyer lemon trees need moderate water, especially in summer and container grown trees should never be allowed to completely dry out. Regular application of a citrus fertilizer will keep the foliage dark green and the tree productive. Although the Meyer lemon is susceptible to many citrus pests and diseases, well tended trees are generally pest and disease free. Management guidelines for citrus pests and diseases can be found in UC IPM Pest Management Guidelines for Citrus referenced below.
- University of California Riverside Citrus Variety Collection:
- UC IPM Pest Management Guidelines for Citrus:
- Meyer Lemon Wikipedia Entry:
- Discussion of the Improved Meyer Lemon Program:
Reuther, Walter; Leon Dexter Batchelor, E. Clair Calavan, Herbert John Webber, Glenn E. Carman, Robert G Platt (June 1989). Citrus Industry: Crop Protection. University of California. p. 195. ISBN 0-931876-24-9.
- Author: Bud Veliquette
In a couple of days, we will be moving back to Sonoma County, so this will be my final blog for the Solano Program. We will miss being in this nearly frost-free climate of zone 17, but we are happy to be back in a forested rural area. Our home in Occidental is in Sunset’s zone 15, where winter temperatures can dip into the upper 20’s during a cold snap. The New Sunset Western Garden Book shows a detailed climate zone map of the entire Bay Area (pages 32,33), including the inland Delta areas. Aside from the milder zone 17, Solano County includes a big chunk of zone 15, 14, and 9, which is near Vacaville.
One way to beat the frost is to plant the most sensitive plants, like Lantana (Lantana camera) with some other more frost hardy plant, like California lilac (Ceonothus spp.) (see photo), seen cascading over a retaining wall in my neighborhood. The evergreen foliage protects most of the sensitive parts of the Lantana as an unexpected symbiosis.
Bougies to Go
For those of you like me who can’t stand to go without a Bougainvillea (Bougainvillea spectabilis), my solution to zone 15 living is to pot them, which makes them portable and easily placed in a protected place during a frost alert. (see photos)
Break out the Frost Covers
And yes, I’ve found that you can have avocados (Persea americana) in zone 15. But you do have to keep the frost covers handy during the coldest months. We have two at our Occidental condo, and I got the hardiest ones I could find: ‘Mexicola’, which is very cold hardy to 20 degrees F. The Meyer lemon (Citrus x meyeri) is also a favorite of mine. It’s best to get early ripening varieties in frost prone areas, because fruit is damaged at several degrees below freezing. However, frost covers can raise the temperature by 6 degrees, which often is just enough to protect the fruit.
Late Blooming Apricots
I had given up on trying to grow apricots (Prunus armeniaca) in zone 15, but recently I found two late blooming varieties: ‘Harcot’, and ‘Harglow’. The latter is also disease resistant. So, I’ll be putting one or two dwarfs in, in another month or two.
Enjoy this beautiful fall weather.
- Author: Betsy Lunde
Here I am again thinking about the citrus talk on June 23 at Annie’s Annuals by John of Four Winds Citrus and trying to remember all the details of that great talk. When I last visited with all of you via the Master Gardener Blog, I was discussing his ideas of fertilizing your citrus trees. So here we go again . . .
My last sentence was regarding the use of the fertilizer stakes: John does not recommend them as the stakes can create “hot” spots which can burn the roots. He prefers the liquid fertilizers. However, John advised us that he uses time-release fertilizers in the winter months, right up to Thanksgiving. This is a stressed point: Always go into a freeze watered. Water the ground around the tree for the best protection. Keep the citrus trees hydrated during the cold, especially if the temps are going to hit the mid to low teens as a dry, un-watered tree is the most susceptible to the cold. The rule of thumb: the more cold-sensitive the citrus, the faster it grows --- The more cold-hardy the tree, the slower it grows. Goody for our teams who have the slower growing trees! John didn’t tout very many named products, but he did mention “frost bonnets” which Four Winds carries in 3 sizes. Also the use of Christmas lights (the old, warm kind not the new LEDs) can keep the frost at bay; or, just use bubble wrap. Just remember to remove during the day.
Always know where the graft is on your citrus trees. Remember, that all the growth below that graft is root stock! To find the graft, check the trunk of your tree to find the slightly thicker area which is the graft. Some grafts will be vertical like (a V), some grafts will be horizontal around the truck (which can make for a less hardy graft if the tree grows on one side much more than the other.
All citrus have thorns, some varieties more than others. Thorns are NOT a sign of suckers! Only remove the growth below the graft lines to control suckers. Red or purple new growth on lemons equals good fertilizing habits. Too much nitrogen equals leggy, spindly growth.
Some of John’s “per says”:
- Remove all sucker growth.
- Remove growth touching the ground; this allows air circulation inside the canopy of the tree.
- What pruning needs to be done is for strictly cosmetic or looks and is just elective. Citrus trees really don’t need pruning except in case of a broken limbs.
- Removing the “water sprout” (straight upward growth of leaf-bearing stems) doesn’t need to be done unless those branches are keeping lights from inside the tree.
- Don’t worry about crossing limbs – that’s the way citrus grow.
- Remove too many limbs and branches, and sun burn/sunscald can occur on the trunk and larger branches.
- DO NOT pinch the tips on citrus; this will merely result in a tree that has the “pom pom” look.
John advised that the Four Winds website has links to pests, diseases, and products which deal with both. As pesticides, he recommends the following: Orange Guard by TKO; Safer Soap products; and horticultural oil. For ants, Four Winds uses Terro (the product name); Boric acid, and of course IPM (Integrated Pest Management): easiest way to remove scale is blast of water hose – this is also good for aphids. John personally uses his thumbs to remove both scale and aphids or a pencil for to pry larger scale off. This last is not for the squeamish, but effective.
Remember when fertilizing citrus during the warm months that citrus pull fertilizer from the drip line, so piling on the selected fertilizer around the trunk isn’t too helpful. You can use granular fertilizers at 60 degrees and above, but suggest liquid for the rest of the year-round applications.
John has his favorite for the home grower: for an orange, he picked the ‘Washington Navel’ as a hardy, easy-to-grow tree; for the mandarin, he favors ‘Gold Nugget’ which not only ripens in the Spring but is quite cold hardy (mine got zapped in the cold but recovered very nicely and didn’t have much die-back). Lemon, he likes the ‘Meyer’; the grapefruit, he selected ‘Oro Blanco’, but advised that the ‘Rio’ (red)
might be better for those who prefer red grapefruit. Limes, he preferred. the ‘Bearss’ as the best for California gardens. The “Kaffir Lime” is recommended for those who cook and eat Near Eastern cuisine. Did you know that the leaves from the “Kaffir Lime” can be frozen for use later?
Another citrus he mentioned for the home grower is the ‘Yuzu’, an acidic citrus with highly aromatic, bumpy rind. Both the juice and peel are prized additions in Asian cooking, especially for ponzu sauce. This tree is extremely hardy into the high teens. It can be used from green rind to yellow color. Be warned, this tree has large thorns and is rangy in appearance.
When deciding what to plant, remember to plant just enough for your family to eat. Also plant trees that produce what your family will eat. It’s not cool to have a ton of fruit rotting on the ground that no one will eat or give to others. Speaking of picking citrus, John suggests that we cut the fruits from the tree leaving them with a short stem, that way the fruit will last longer indoors and the tree can keep its smaller branches intact.
The rest of this blog will be the answers to questions that were asked toward the wind-down of the talk:
- If there no fruit on the tree or no blossoms: You may be carefully nurturing rootstock or, most commonly, the fertilizer doesn’t contain the trace elements required by citrus –check the label.
- “Sour lemons”: 99.99% of the time the tree is merely lemon rootstock.
- Fruits dropping: Citrus will self-thin fruits; if the fertilizer lacks the proper Phosphorus (P) or Potassium (K), more pea-sized fruits will drop.
- A red grapefruit that is not sweet is probably a ‘Ruby’ which needs more heat than our area can give.
- Deer don’t like citrus, but rats do!
- Too hot fertilizer will show up at burnt leaf tips.
When a freeze is near – DO SOMETHING!! Anything: Water, cover, or both!
'Meyer' lemons always shed leaves throughout the year. Not to worry. Again, thorns are natural on citrus trees. If you don’t like getting stuck, you can break or cut them (carefully), the thorns will not grow back.
Fruit color is not a clue to the ripeness of the fruit. The color is actually dependent on the coolness of the nights. Ripe citrus develop a natural carnauba wax coating – look for a waxy sheen on the ripened fruit. Dig up citrus for transplanting in the spring. Paint the trunk of the tree with either a white or light-colored latex paint to prevent scald or sun burn on the trunk. Citrus trees don’t cross pollinate, they are self pollinating, so that a single citrus tree can be alone in the yard.
If the fruits on your citrus tree are distorted then: Congratulations, you probably have citrus bud mites!
When to repot a citrus tree in a pot when the roots are peering out the drainage holes.
Repotting per the industry standard:
- A 5 gallon tree into a 7 gallon pot
- A 7 gallon tree into a 15 gallon pot
- A 15 gallon tree into a 24 inch pot
- A 24 inch pot into a ½ wine barrel
Remember to disinfect your pruners between root prunings, 10 parts water to 1 part bleach. And the final line from John: “use “el cheapo” water meters before watering; it is a good learning tool for the developing your water common sense”. Never leave in the pot or the water meter will die a premature death!
His word on HLB or Citrus Blight: by the time you notice it, your tree is already gone! See what you missed!
- Author: Betty Victor
Sometime ago, I wrote about my sad lemon tree that had blossoms and no leaves. Well now it has one green stem with 2 leaves and a small lemon, yes a lemon!
If you remember this is the tree that I consulted a citrus grower, looked on the IPM web site, and contacted Lance Walhem, who wrote a book on citrus, and they were stumped as to what was going on with it and so they could not give me any information on what I could do.
So I decided to let it be and only water it, when I watered my other citrus. I did not even give it any fertilizer as I was sure it would not survive, and it is still a very sad looking tree. I am not sure it is going to survive, but maybe the tree has made the decision to try and survive.
I will be surprised if the lemon it has stays and continues to grow to maturity, but for now it has a lemon.
- Author: Betsy Lunde
On Saturday, June 23, there was an amazing talk by John “Cedar” Seeger of the Four Winds Citrus Growers. He held court at Annie’s Annuals in Richmond. The day was perfect, sunny but not too warm with a gentle breeze as we were given a lecture – fun, not dry – on citrus growing in the Four Winds style. First, though, a few facts about the company.
Four Winds was started in 1946 by Floyd Dillion, a transplant from the Mid West. He came to California to start his own business and because he LOVED oranges, decided to start growing them. He was rather a visionary to notice that men coming home from the War were buying their own homes. He also noticed that the typical house of the time had a small yard with a patio. There was not enough space for a standard size orange tree in those yards, so he decided to figure out how to make the trees smaller or “dwarf” sized so that the tree could be grown in a pot. Through breeding and with plain old hard work and luck, he was able to hybridize dwarf sized trees! His goal of “every yard, an orange tree” was eventually realized. Today Four Winds is the largest producer of dwarf citrus trees.
Floyd is gone now, but his descendants still own the business. His grandson runs the main office in Southern California, while his grand-daughter and her husband (John) run the growing fields in Winters.
Things we learned from John:
How we grow our citrus trees effects the size of the tree. We can control the size of the tree when we grow in containers. If we take a “pip” or seed from an orange and plant it, we will get a tree that will be standard-sized or quite large. If we buy a tree already started, it can be a “semi-dwarf” or a “dwarf” sized tree. The size of the last two is dependent on the root-stock used. It is a good idea to check the tag for the growing size. This is to assure that the tree will fit within the limits of your yard.
John brought up root-stocks for several reasons: 1) the root stock effects the entire tree’s growth; 2) folks get confused as to why citrus on the tree is not consistent with fruit of past seasons (sound familiar?); 3) folks don’t know why the tree has a different foliage pattern than before. John brought up the root stock known as the “Flying Dragon”, a trifoliate-leafed plant primarily known for the wicked knife-like thorns. It used to be a popular and common root stock but is now grown as a “security gate” shrub for around houses and businesses. Four Winds uses a total of 8 root stocks for its propagation of citrus.
Root stocks are chosen for the different varieties based on hardiness and, believe it or not, for seedlessness. In the business, the cutting is the fruiting variety, while the mother is the root stock.
98% of all troubles growing citrus = TOO MUCH WATER! According to John, “drainage is everything”. If you have bad drainage, grow your citrus in containers or on a mound. The mounding method works well as the roots of a citrus of any size are 2 feet down. The exception is if you plant a seed into the soil where it will form a tap-root. Citrus purchased will not form tap roots. It take 5 years to have a citrus tree fill in a wine barrel; by that time, the tree should be 6 feet tall. Plant in a sheltered spot; would you believe that the Meyer lemon is a great houseplant even in California? John swears it’s true!
When you plant a citrus tree in its new container, the top roots, those little frilly roots should be at the surface. If your tree appears to be in “suspended animation” or isn’t showing any signs of growth, physically expose those top roots yourself – it will start showing new growth again.
Citrus trees need more than just N, P & K (nitrogen, phosphorus and potassium). Use a 3-1-1 or multiples of that formula with trace elements. Sea weed products or finished compost supply these needed traces.
If you planted your citrus in or near the lawn, remove the sod or grass no less than 4 feet from the base of the tree. Water the tree with 5-7 gallons of water once every 7 days. In Winters, John waters the nursery trees 3 times a week, with one of those watering containing fertilizer. He suggests that we fertilize citrus year around; those in the ground monthly. A containerized tree can have a thick layer of compost instead on top of the soil. “Good roots = good tops”; healthy roots are either white or tan and firm to the touch. Don’t use fertilizer stakes on the citrus as they can create “hot” fertilizer spots which can burn the roots.
There was more excellent information which I will put down in my next blog.The talk was good, the company fine, the weather lovely, and the shopping afterward was divine!
PS: John LOVES the Master Gardeners!