What Is the Best Mix for Potted Citrus Trees?

“What is the best potting mix for Meyer lemon tree in a plastic pot?  Needs to drain well.” Question from Polly of New Mexico

Answer: We offer several good-fit mixes. Before potting your tree, make sure that the new pot is several inches larger than the old and that it offers excellent bottom drainage. The ideal potting soil should have a balance of good porosity, drainage, and water-holding ability. Ideally, it should be slightly acid, because Meyer lemons grow best in soils with a pH of 6-7. Here are our best OMRI Listed soils for your tree.

  1. Black Gold Natural & Organic Potting Mix
  2. Black Gold Natural & Organic Ultra Coir
  3. Black Gold® Natural & Organic Flower and Vegetable Soil

Growing Potted Citrus

Potted citrus trees require a minimum of 8 hours of sunlight a day to perform well. Warm growing conditions (60 – 75 degrees F) and moderate humidity (45 – 50%) will encourage flowering and fruiting. Bringing plants outdoors in summer, on a sunny porch or patio, helps them grow better year-round.

Good watering, feeding, and care practices will keep your plant happy. Water plants deeply until the water drains from the bottom of the pot. Allow pots to become moderately dry between watering–the tops should be dry down to a minimum of 3 inches. (Outdoor plants may need to be watered almost daily, while indoor plants require less frequent water.) During the winter months, when growth naturally slows, the watering regime should be reduced. Signs of overwatering include leaf yellowing and drop and eventually stem death. Trees allowed to become too dry may also unexpectedly drop some leaves.

Fertilization is essential, any slow-release fertilizer formulated for citrus would be ideal.

I hope that these tips help!

Jessie Keith

Black Gold Horticulturist

How Do I Bud Graft a Lemon Tree?

“I need help grafting a lemon tree branch to my small lemon tree (3 ft. tall). How soon should I graft the tree so the fruit can grow, or is 3 ft. tall OK to graft? What is the best technique for grafting? Is there any plant hormone that I should use for the best results?” Question from Elaine of Daytona Beach, Florida

Answer: Your lemon tree is not too small for grafting. It is not too tricky to graft lemon tree scion onto a dwarf plant (rootstock) as long as the two are compatible, you use healthy stock, and you follow all directions. There are a couple of methods you can try, which do not require supplementary hormones. You will need some special materials, and timing is important when grafting plants.

From what I have read, citrus trees should be ‘bud grafted’ using techniques called ‘chip budding’ or ‘t-budding.’ So, you will be grafting buds rather than branches. Bud-grafting of citrus is best done from mid-spring to fall when plants are actively growing, and it is easy to cut away buds.

Bud Grafting Citrus Trees

Grafting tape protects the graft union and holds in moisture while the bud and rootstock grow together.


Directions: (Click here for more elaborate steps with visual guides for chip budding. Click here for a more elaborate description of t-budding.)

  1. Clean: Clean your grafting knife with alcohol and paper towels between cutting each bud and branch.
  2. Collect: Collect bud-wood using your knife. Be sure to cut away the bud leaving a long chip of wood at the base (see above) to supply it with nutrients and create a good union.
  3. Incise: Make an incision on the rootstock (as shown above).
  4. Graft: Slide your buds into incisions so that they fit well.
  5. Wrap: Wrap the buds with grafting tape.
  6. Tend: Tend to the bud for three or four weeks. Rewrap it if the film becomes loose.
  7. Unwrap: After a month or so, unwrap the buds. The grafted buds should look healthy, and you should see a union of cells and tissue between the bud and branch.
  8. Force Growth: Next you must force the bud to grow by damaging the stem above it so that your new grafted bud is the primary bud at the top of the branch. Identify the closest bud above your grafted bud, cut it in half, and bend it downward. This will encourage your new grafted bud to “take charge” and grow as the primary bud on the branch.

For more details, please click on the links above. They provide full grafting guides for citrus along with lots of informative visuals.

Happy grafting!

Jessie Keith

Black Gold Horticulturist

Why Are the Leaves on My Potted Lemon Tree Disfigured?

Why Are the Leaves on My Potted Lemon Tree Disfigured?

“Ever since I started my lemon tree from seed, its leaves appear cut around the edges. I’m not overwatering. Today I gave it Jobe’s Organics Fruit & Citrus fertilizer and treated with Bonide Systemic Insect Control, both of these being used for the first time, as I haven’t done anything but water and mist it since its birth. When its first leaf appeared, it was small and oddly shaped. I thought it was a “lucky” leaf, like Nemo’s “lucky” fin in Finding Nemo (lol). I have kept a fan on it on medium to make it strong that continues to run (for months and months now). I don’t think that’d be causing this. If it’s a pest, I have no idea which one. Thank you so much for your time.” Question from Bradley of Cleves, Ohio

Answer: There are a number of reasons that may explain why your citrus leaves look malformed and discolored. Both physical and nutritional problems are among the possibilities. Let’s start by covering the essentials for growing indoor citrus.

Indoor Citrus Growing Needs

Indoor citrus trees require a minimum of 8 hours of sunlight a day to perform well in addition to warm growing conditions (6075 degrees F) and moderate humidity (45 – 50%). Bringing plants outdoors in summer, on a sunny porch or patio, helps them grow better year-round. Plant them pots that drain well, and provide a potting soil with good porosity and water-holding ability, such as Black Gold Natural & Organic Potting Mix, which is OMRI Listed for organic growing. Regular fertilization is essential, but pots require light fertilization with granular fertilizer. Water plants deeply until the water drains from the bottom of the pot. Allow pots to become moderately dry between watering–the tops should be dry down to 3 inches. (Outdoor plants may need to be watered almost daily,  while indoor plants require less frequent water.) During the winter months, when growth naturally slows, the watering regime should be reduced. Signs of overwatering include leaf yellowing and drop and eventually stem death. Trees allowed to become too dry may also unexpectedly drop some leaves.

Troubleshooting Your Citrus Woes

It helps to take potted lemon trees outdoors in summer.

Lack of fertilizer, excess fertilizer, and low humidity can all contribute to the leaf troubles you are experiencing. Your tree had no fertilizer for a while, which can cause various nutrient deficiencies, and now it has a lot if you used Jobe’s Organics Fruit & Citrus fertilizer spikes. Moreover, the fan may help with stem strength, but fans are also drying and reduce humidity.

Here are my recommendations: Make sure your tree is in a well-drained pot, provide it with lots of sunlight, remove the fan, remove the Jobes’ Organics Fruit & Citrus fertilizer spike and replace it with a granular citrus fertilizer that can be added at lower quantities, and take your tree outdoors in summer to improve stem strength. Also, refrain from using Bonide Systemic Insect Controls. Systemic insecticides are not suited to edible plants because they poison plant tissues. That is why systemic labels says: “It is not meant for vegetable or fruit plants.” Insecticidal soaps are quite effective on most pests. It also helps to occasionally wipe the leaves down.

I hope that this helps your little citrus tree. Be sure to water it a little less in winter to avoid root rot. Generally, citrus trees from seed take several years before they are fruitful. (Click here for more tips on growing indoor citrus.)

Happy gardening,

Jessie Keith

Black Gold Horticulturist

Why Is My Key Lime Losing Flower Buds?

“I have a Key Lime tree that keeps losing the flower buds, so we never get any Key Limes. Do you have any suggestions for the soil that may help? I water the tree every other day during the dry season, and every 3-4 days during our rainy season. Thank you.” Question from Jenifer of St. Petersburg, Florida.

Answer: You can always expect some natural bud drop in any citrus, including key lime (Citrus × aurantiifolia). Flower buds and blooms will typically occur in waves from mid to late winter. If your key lime is losing all of its buds, then many different factors could be the cause. These can include:

  1. Excessive water or extreme drought
  2. Extreme temperature fluctuations
  3. Pest or disease problems
  4. Nutrient deficiency
  5. Leaf loss due to hurricane damage
  6. Dry air

You seem to be watering your tree quite a lot. If it appears to be very healthy, then water it less and make sure you are feeding it with a fertilizer formulated for citrus. Reducing water can actually induce flower bud set! If it looks unhealthy, send a picture, so I can better target the specific problem.

Happy gardening,

Jessie Keith

Black Gold Horticulturist

Growing Lemons, Oranges, and Other Citrus Indoors

Mature Chinotto Sour Orange (Citrus x aurantium ‘Chinotto’) Fruits. (Image by Jessie Keith)

From the seventeenth to nineteenth-century European aristocrats in the north grew citrus and other tender fruits in specialty greenhouses called orangeries. By the early Renaissance, pane glass could be sufficiently produced for the creation of greenhouses large enough to hold tropical and subtropical fruit trees. These glasshouses were status symbols, in addition to being functional.

Fine examples still existing palace grounds from the period, to include the Versailles Orangerie, which housed 3000 citrus trees in its heyday. The indoor cultivation of citrus was also perfected at this time, and much of what was learned then still benefits gardeners today.

Many citrus trees produce mature fruit from fall to winter. This is why temperate gardeners must grow them indoors in winter. Choosing the right varieties for indoor culture and giving them the right care will ensure fruiting success.

Good Varieties for Indoor Growing

Orangerie Kruidtuin in Leuven, Belgium (Image by Athenchen)
The Orangerie Kruidtuin in Leuven, Belgium (Image by Athenchen)

For starters, gardeners wanting to grow their own citrus need to choose compact varieties developed for indoor growing. If you start your own orange or lemon from seed, it can take 8-12 years before the plants will begin to fruit. Seed-grown plants will also be very large and quickly outgrow most indoor sunrooms or conservatories without regular pruning.

Good varieties include the calamondin (Citrus x microcarpa), Fukushu kumquat (Fortunella obovata ‘Fukushu’), Chinotto sour orange (Citrus x aurantium ‘Chinotto’), Thai lime (Citrus hystrix), Meyer lemon (Citrus meyeri). All set fruit reliably—especially the calamondin and kumquat. Those purchased from specialty nurseries for pot culture are often grafted onto dwarfing rootstock, though happy specimens may still reach 8 to 10 feet without pruning.

Planting Potted Citrus

Kumquats growing in a winter conservatory. (Image by Abaddon1337)
Kumquats growing in a winter conservatory. (Image by Abaddon1337)

Plant your citrus in an excellent potting mix with good drainage and a slightly acid pH. A 1:1 combination of Black Gold Natural & Organic Potting Mix and Black Gold Cactus Blend will offer a balance of good drainage and needed organic matter for good nutrient and water retention. Plant trees in a substantial, well-drained pot with a fitted saucer. Trees will likely stay in the pot for years, so choose something attractive and well made. The pot should be just a few inches wider than your tree’s root ball. Dwarf trees may begin to flower and fruit at three to five years of age, depending on the variety.

Indoor Citrus Flowering and Fruiting

Successful fruiting starts with healthy flowering. Most varieties flower most heavily in late winter and early spring, but many recommended for indoor growing will continue to flower up until fall. (Click here for a full Citrus variety flowering and fruiting chart.) Almost all cultivated citrus are self-fruitful, which means that they will set fruit on their own without needing another tree for cross-pollination. Good sunlight, fertilization, and care will encourage healthy flowering. The right seasonal care is also essential.

Citrus Year-Round Growing Needs

In summer, bring potted citrus outdoors on a sunny porch or patio. Trees require a minimum of 8 hours of sunlight a day; 12 hours is better. Bathing them in the sunshine will encourage vigorous growth for more successful fruit production because this is the season when newly-set fruit starts to develop. It typically takes between six to nine months for lemons to mature and up to 12 months for oranges and related citrus to mature. During this time, provide them with a quality fertilizer formulated for fruit and citrus and apply as directed.

Cody Hough800px-Calamondin_Orange
A fruitful calamondin orange. (Image by Cody Hough)

Water plants deeply until the water drains from the bottom of the pot. Allow pots to become somewhat dry between each watering–the tops should be dry and the soil below should be moderately dry (stick your finger down to a few inches if you are not sure). Outdoor plants may need to be watered once every 3-4 days while indoor plants may need to be watered every 5-7 days. During the months, when growth naturally slows, the watering regime should be reduced. Signs of overwatering include leaf yellowing and drop and eventually stem death. Trees allowed to become too dry may also unexpectedly drop some leaves.

Those living in zones below USDA hardiness zone 9 must bring their potted citrus indoors in fall. Choose a cool, sunny indoor location. Plants placed in a low-light location with less than 6 hours of sunlight should be provided supplemental light with high-spectrum grow lights. Citrus trees never go fully dormant but instead undergo a period of quiescence during the cold months when growth slows and leaf set stops. During this time, reduce watering and feeding and allow trees to rest. Keeping them in a cool (40-50 degrees F) but humid location during this time is also important as it helps facilitate their natural cycle.

Indoor Citrus Pruning

The highly fragrant, waxy, white flowers of citrus trees will appear in spring. Pruning can occur at any time when plants are actively growing. Simply pinch back growing points and cut back unruly branches. Leggy growth indicates plants are not getting enough light.

Indoor Citrus Pests and Diseases

Citrus reticulata 'Encore' (Mandarin Group)
Citrus flowers are white, waxy, and wonderfully fragrant.

Scale is a common problem that occurs on Citrus stems and branches, and aphids, whiteflies, and spider mites are sucking insects known to plague foliage. Horticultural oil and insecticidal soap can help reduce indoor pest problems. Keeping stems and leaves clean is always a good practice; especially when bringing plants indoors in fall. Cleaning stems and leaves and treating them with horticultural oil will keep any hitchhikers from coming indoors. Common fungal diseases, nutrient, and physiological ailments are also known to cause all manner of problems with Citrus. To learn more about frequent pests, diseases, and solutions, visit the UC Davis IPM page for Citrus.

The joy of growing your own citrus is knowing that these long-lived house plants will produce fruits for over 50 years, with good care. To determine when your fruits are ready to harvest, wait until their skins are fully colored and then pick and test a fruit. If the flesh is juicy, and it tastes good, it’s time to harvest!

Growing Limes for Perfect Tequila Tasting

Nothing tastes quite like fresh limes straight from the tree, and they’re easy to grow!

The Cuervo Gold tequila we all swore off of so many times in high school has some big competition these days. There are now over 600 tequila brands on the market and high quality imports elevate this drink from spring break slammers to uptown tasting parties. With tequila coming up in the world at well over $50 a bottle, you’ll want to know a bit more about growing the bartender’s lime to match. Growing limes is easy!

Mexican Lime

Centuries ago, Arab traders brought limes from Asia to the Middle East where Crusaders carried them home to Spain, and later into Mexico. The species Citrus aurantifolia has since split into varietal groups to include larger Key limes and the smaller Mexican “bartender’s” lime. The latter produces the best lime for tequila aficionados.Mexican limes have the thinnest rind of all citrus. This allows the fruit to dehydrate so quickly its cold storage life is severely limited. Store bought limes rarely retain that fresh-picked in flavor, but if you grow your own Mexican limes in a large pot, you’ll enjoy the freshest fruit possible with every tequila tasting.

Beautifully contained lime trees in England.
Beautifully contained lime trees in England.

The Mexican lime variety available from premier citrus growers is Citrus aurantifolia ‘Mexican Thornless.’ This lime tree blooms over spring and summer with small white blossoms that release a heady citrus fragrance. It is very frost tender and best grown in a large pot you can move under cover or indoors for the winter. The container should have not just one, but numerous drain holes in the bottom to ensure there is no over-saturation occurring deeper down.

Growing Mexican Lime

Because all citrus are picky about drainage, use Black Gold Natural & Organic Potting Soil where summers are humid. In the depths of the Southwest, where summers can be very hot and dry, Black Gold Cocoblend Potting Soil will help retain more moisture in the dry heat. For established container-grown limes or other citrus, use Black Gold Citrus, Avocado & Vine fertilizer each year to ensure a plentiful harvest.

Mexican limes are frost-damaged by temperatures below 30 degrees F. Key limes may be slightly more hardy. Either way, plant them in a protected spot or use a large planter with wheels to ensure you can move yours to protection on cold nights or for the entire winter. For those willing to do so, draping a protective blanket or bed sheet over a smaller tree on cold nights is a temporary, yet effective, strategy for overcoming periodic frost.

The biggest challenge is protecting tender citrus tree bark, which is highly vulnerable to sunburn. This is why they are painted white in the orchard; the paint provides the same benefits that zinc oxide provides human sunscreens. You can do the same with watered-down white interior latex on your homegrown citrus too. If not painted, sunburn can result and cause blistering or long cracks in the bark, which cause moisture loss and increase pest and disease vulnerability.

To keep a potted tree to a limited size, thin out interior branches at any time. Time your pruning well by waiting until after fruit harvest to avoid interfering with the flowering process. If you’re growing ‘Mexican Thornless’, any suckers from below the graft union should be promptly removed as they bear large painful barbs.

If memories of tequila shots on the Mexican Riviera seem far more flavorful than those of tequila parties further north, it’s not your imagination. Freshness is everything when you bite into a lime wedge. Why not bring a little bit of Mexico to your own backyard, so whenever life gives you too many lemons, you can always break out the tequila and limes.