Growing Citrus in the Ground
Growing dwarf citrus trees in the ground can be immensely rewarding, and it naturally produces the biggest and most vigorous specimens. However, before planting a citrus tree in the ground, you must determine whether or not the location you have in mind will provide a suitable home for your new dwarf citrus tree.
On this page:
How Will It Look? | Climate | Location
Soil | Planting | Watering | Fertilizer | Mulches
Suckering | Thorns | Pruning | Pollination | Espaliering
Beneficial Insects | Pest Insects | Frost
How Will Citrus Look In My Yard?
Sometimes people aren't quite sure about using citrus as a landscape plant. In fact, citrus work extraordinarily well in most any landscape, offering beautiful evergreen foliage, lovely (and fragrant) blossoms, and colorful fruit. If you'd like to see some examples of successful landscape plantings, take a look at our landscaping slide show.
Citrus trees purchased through our mail order website are all grafted on dwarf rootstocks that are perfect for container growing. If planted in the ground dwarf trees can be expected to reach “Semi-Dwarf” size – up to around 16 feet in height, depending upon variety. In a pot, the dwarf trees will stay much smaller, especially with judicious pruning. Standard size citrus trees, available at California nurseries, are best suited for growing in the ground and can be expected to get much taller – up to 25 feet, depending on variety. Be sure to provide more space in the ground for standard size trees. Generally, a Dwarf tree needs an 8-10 foot diameter space, while a Standard tree should be provided with a larger growing space – up to 15 feet in diameter.
In general, ground-planted citrus trees are happiest in warm, temperate areas. Some varieties are much more frost-tolerant than others. For information on a specific variety, please refer to our hardiness table.
A sunny, frost and wind-free location with southern exposure is best. (If in doubt, leave the tree in its plastic container and place it in the spot you have in mind. Water as needed, and after a week or two you should be able to tell whether or not it's happy.)
Reflected heat from sidewalks, walls, driveways, or other structures can help to create a warmer "microclimate." Avoid planting citrus trees in lawns that get frequent, shallow sprinklings. Don't crowd your tree, for even though it is a dwarf, it will need room for its eight-ten foot ultimate diameter. The root system can reach far beyond the drip line.
Citrus trees are famous for tolerating a wide variety of soils, including clay. However, good drainage is essential, as citrus trees can't survive standing water for long. To test your drainage, dig a hole 30" deep where you would like to place the tree. Fill with water to saturate the soil. The next day refill it with water. Your drainage is OK if the water level drops 2" in two hours. If the water does not drain well, plant your tree in a raised bed and then amend the soil as described in the following paragraph.
Soils rich in humus are best. For heavy or poor soils, we recommend digging a large hole and filling it back in, half with the best of the original soil, and half with a good-quality amendment mix. Plant the root ball high to allow it room to settle over time. Crown roots should remain visible just above the soil line.
If the plant is growing in a container, gently invert the container to remove the soil intact. Trees that are somewhat dry will usually release more easily from the pot for transplanting. Squeezing the sides of a plastic pot can help to loosen the soil and roots. If planting a bare-rooted mail order tree, shake loose the shavings the roots are packed in before planting. Add the shavings along with your other amendments to the prepared mix for the planting hole.
Take note of the abundant fibrous root system. Straighten out any circling roots and cut off any broken or dead roots before planting. Amend your planting hole as described above. Do not add fertilizer to the soil while backfilling your hole; however, you can apply some to the soil surface after planting. Be sure to tamp soil lightly as you go and water thoroughly after planting to eliminate any large air pockets. Stake the tree as needed until well-established. Green plant tie is a good choice for tying trees to stakes.
Citrus trees are best planted during the active growing season. In summer it is best to plant in the early morning hours when temperatures are cool to moderate. Try to keep the roots out of the sun as much as possible. Water thoroughly after transplanting. If desired, use a solution of Vitamin B-1 Rooting Tonic in the first few irrigations to help fine feeder roots recover more quickly. You may wish to pinch off fruit and blossoms for the first year or two after a new planting to encourage stronger root and branch development.
Consistency is the key with citrus watering! As with so many plants, citrus trees like soil that is moist but never soggy. How often to water will vary, depending on soil porosity, tree size, and temperature. Allowing the top of the soil to dry slightly is OK. A simple moisture meter, available at garden supply stores, can be used to determine moisture down to about a 9” depth. Generally, when the meter indicates a root moisture level of about 50%, (center of dial) it is time to water. Always store your moisture meter dry between uses to keep it functioning properly
A wilted tree that perks up within 24 hours after watering indicates the roots got too dry. Adjust watering schedule accordingly. A tree with yellow or cupped leaves, or leaves that don't look perky AFTER watering can indicate excessive watering and soggy roots. In that case, water less frequently.
In the ground, citrus prefer less frequent, deep waterings to frequent, shallow sprinklings. Creating a watering basin around the drip-line of the tree can aid in deep watering. As the tree grows, be sure to expand the basin as needed to keep it as wide as the spread of the branches. Deeper watering promotes deeper root growth and strengthens your tree. Generally, once-a-week watering works well for in-ground plantings. Be sure to adjust based on weather conditions!
In general, it is probably best to water in the morning, but if plants are dry or wilted it is better to water them immediately, rather than wait until morning. See our watering page for more.
Citrus trees feed heavily on nitrogen. Your fertilizer should have more nitrogen (N) than phosphorous (P) or potassium (K). Use at least a 2-1-1 ratio. Miracid Soil Acidifier is a water-soluble product that works well and is a 3-1-1 ratio. In some regions, you may be able to find specialized citrus/avocado fertilizers. Buy a good brand and apply according to package directions.
Any good citrus formula will contain trace minerals like iron, zinc, and manganese. Many all-purpose products will work. Just add trace mineral supplements if your fertilizer is deficient. We prefer slow release fertilizers in the granular form rather than fertilizer stakes. Follow rates on the package carefully as fertilizers come in different strengths, release rates, and application schedules. We recommend that you fertilize more often than recommended with most slow release fertilizers. Foliar applications of trace minerals in the form of kelp or other soluble fertilizers can be effective. Yellowing leaves indicate lack of fertilizer or poor drainage.
Commercial organic fertilizers can work well for citrus trees. Lily Miller, Dr. Earth and a number of other companies now sell Organic tree fertilizer formulations. Supplement granular applications with foliar sprays of fish emulsion and kelp. Some people brew compost ‘teas’ which can be helpful when applied to plant roots.
Liberal use of mulches will conserve precious water and help inhibit weed growth. A 2-3 inch layer of redwood shavings, fir bark, compost, or other organic matter can be very helpful for water retention. To reflect heat and hasten fruit ripening, some people mulch with light colored gravel or crushed rock. “Living mulches” such as nitrogen fixing clovers can also be planted between trees in an orchard. To avoid root diseases, always keep grasses and other vegetation away from the root collar area. Keep all mulches at least six inches away from the base of the trunk.
Know where the graft union is on your tree. It can usually be seen as a diagonal scar between 4 and 8 inches from the soil. Remove all shoot growth below the graft. These so-called "suckers" take vitality from the top of the tree (the fruiting wood). Especially on young trees, they are very vigorous. Remove suckers as soon as they are observed. See photos.
Thorns are removed from rootstocks when they are grafted. Juvenile fruiting wood will sometimes have thorns. This is a young plant's way of defending against grazing animals. As the tree matures, thorns will not appear as often. Prune off thorns if desired.
Citrus may be pruned as desired to achieve the look you want. Pruning is fine any time of year, except in the winter for outdoor trees. Pinching back tips of new growth can help trees to maintain a round form, without impacting future fruit.
Citrus will look fuller with occasional pruning to shape leggy branches. Very leggy branches can indicate the need for more light (etiolation).
Some trees may develop erratic juvenile growth above the graft. Don’t be afraid to completely prune off an erratic branch if it is too irregular or crossing another branch. Other fruitful branches will replace it. Any growth above the graft can eventually bear fruit. Well-pruned trees have higher fruit yields and are less prone to branch breakage.
Citrus are self-pollinating, even indoors. Some people enjoy pollinating their trees and can do so by using a small soft brush or cotton swab to transfer pollen among the flowers.
Citrus trees can be trained fairly easily to grow on trellises. Simply use green garden ties to hold branches in place and prune to encourage desired branching patterns. Select specimens with an open growth habit that will most closely match with your intended espalier design. See this link for some tips on espaliering citrus trees: http://www.gardenguides.com/118929-espalier-citrus-trees.html
Spiders, lady beetles, lacewings, and preying mantids (praying mantis) are just some of the beneficial critters you may see around citrus trees outdoors. You can even buy some predator insects in local nurseries for release in your garden.
One reputable source for beneficial organisms is ARBICO.
It is important to keep your tree free of ants, because they will “farm” scales and other honeydew-producing pests, moving them from place to place, milking their secretions, and protecting them from their natural enemies. Ant baits that contain boric acid may be helpful. A recipe for a homemade ant spray can be viewed here.
If you find harmful insects like scales, aphids, or mites, a household spray bottle of water with some mild dish soap could be all you need. Orange TKO, an organic cleaner, works very well at a dilute rate. You can also find specially formulated Horticultural Soap products at local garden centers. Use a soft toothbrush to scrub away adherent scale insects and recheck in a week to see if another treatment is needed. If scale insects persist, the usual nursery treatment is a 1% solution of light horticultural oil. Learn more.
Many citrus varieties can tolerate temperatures as low as 32 degrees for 2-3 hours. See this chart for the lower temperature tolerance thresholds of different citrus varieties.
Even temperate locations can drop below freezing so it's good to have a plan of action ready. Old fashioned Christmas lights (that produce some heat) can be effective, either alone or in combination with frost covers. Anti-transpirant sprays such as ‘Cloud Cover’ can also be effective when used according to directions. Straw mulches, cloth covers and even plastic sheeting can be combined as needed to provide the necessary level of protection. See this link for more on frost protection options: http://davesgarden.com/guides/articles/view/319/