There are few things better than fresh fruit off the tree in your own back yard. To me, the most wonderful times of the year are those months from January to March when the Navel Oranges, Tangerines, and Tangelos ripen around my house, and of course, the smell of the blossoms that had Old Californians sleeping on dedicated sleeping porches just to smell the perfumed air as they slept.
When I'm out at shows for Old California Botanicals, sometimes people come up who are thrilled to be embarking on this experience for themselves, or maybe they bought a house that has trees already there and maybe aren't producing, and they ask for some advice. Here are five really simple tips and tricks from me, your resident Botanical Specialist and Board Member of the County Farm Bureau, that will help you make your trees happy and have you harvesting like an Old Californian in no time!
1. Pruning for Optimal Growth:
Keep an eye out for crossed branches occurring in a tree, like here in this photograph. When they occur, you will want to select the smaller branch to prune away at its base to prevent the branches from rubbing and creating openings for insects and disease.
While it sounds blindingly obvious, pruning is a key aspect of any tree care, but this is especially true for fruit trees. This is something that is worth your while to think about, because if a fruit-bearing vine or tree is pruned correctly, the nutrients that plant produces are more concentrated in the fruit and the places you want the fruit to be. If you hire a professional, make sure they are certified in how to treat fruit trees, or they have experience pruning for a commercial producer (there are some that serve home gardens!). Try asking around at a local fruit tree nursery.
If you are looking to learn for yourself, it pays to do your homework first, but here are some easy principles to start with:
- Prune during late winter or early spring before the growing season begins for the best results (the exception to this rule is if you have a winter-fruiting or blooming variety, of course. Do not prune while fruiting or flowering).
- Trim back any crossing branches to prevent rubbing and potential entry points for diseases.
- Controlling vertical growth can mean it's easier to pick in later years, but you cannot really prune an already tall tree down to size, so consistency is key!
- Thinning branches improves air flow that reduces the possibility that pathogens or pests could harm your tree
- Cutting branches that straggle to the ground ("skirting" the tree) keeps the tree from producing fruit low to the ground that will attract and be eaten by pests
- Always clean your lopers and clippers before you start pruning, in between each plant, and once you are finished to keep your gear in good condition and your trees free from infections and fungus. Keep a bucket with 10% bleach solution to rinse your tools in, or keep a container of Clorox Disinfecting Wipes with your pruning gear.
2. Strategic Fertilization:
Citrus trees have specific nutrient requirements, and providing them with a balanced fertilizer is crucial for healthy growth and fruit production. Use a specialized citrus fertilizer with a balanced ratio of nitrogen, phosphorus, and potassium, like a 16-16-16 fertilizer (the kind at this link comes in bags of various weights if you don't want to carry around 50 pound bags). Apply fertilizer in late winter, early spring, and late summer to provide a steady supply of nutrients. Be cautious not to over-fertilize, as this can lead to excessive foliage growth at the expense of fruit production.
3. Insect Care and Pest Management:
An image of a mature Oriental Fruit Fly, one of the newest invasive pests concerning citrus farmers and home gardeners alike. Quarantine conditions for both farmers and gardeners already exist in Santa Clara, San Bernardino, and Riverside Counties and it has the potential to spread if precautions are not taken. For more on the quarantines, see this link.
Citrus trees are susceptible to various pests, including aphids, scale insects, and citrus leaf miners. In addition to regular pruning:
- Regularly inspect the leaves, stems, and fruits for signs of infestation
- Consider introducing beneficial insects like Live Ladybugs or releasing parasitic wasps to control pests naturally. Some studies have also indicated that California Brittlebrush, a native plant in Southern California, naturally attracts predators for the Asian Citrus Psyllid (here is a source for Brittlebush Seeds).
- Regular treatments every 2-3 months with non-toxic repellants is also an important part of caring for your trees. Neem oil is an effective organic solution (I like to buy the Neem Oil Concentrate to control potency myself) for managing common citrus pests, plus it also works as a fungicide for your tree, vegetables, or flowering plants like roses. On the fruit trees in my garden, I also like to use BioAdvanced Citrus Tree and Vegetable Root Drench every 2-3 months that absorbs in the roots through watering to provide a natural, internal defense against pests. These measures are important regularly, but they are particularly important to combatting the spread of Citrus Psyllid and Oriental Fruit Fly.
Early detection and prompt action are crucial in preventing pest damage to your citrus tree or your produce, or allowing it to spread to your neighbors. Be sure to report pest sightings to your County Agricultural Department. This link contains identification information for major pests to keep an eye out for if you have citrus trees in California. Sometimes they arrive on the bottoms of carboard boxes, so be sure to check your packages!
4. Proper Watering Practices:
Especially living in a hot, dry climate, you may be tempted to water your citrus tree with some frequency, or it may be planted near sprinklers and so it receives little waterings frequently. In fact, the opposite is recommended practice! Water deeply, allowing the soil to dry out between watering sessions. I find one longer deep soak monthly, particularly during dry periods has worked well for my trees. Ensure the soil has good drainage to prevent root rot, or adjust your watering regimen accordingly if you live in an area with clay soils. After all, some of the best Washington Navel Oranges are grown in clay soils (but this is a matter of considerable heated debate between farmers)! If your tree is getting over-watered or is located near sprinklers, you may notice the leaves will turn yellow; this is a sign to cut back. Adjust your watering schedule based on the climate and the specific needs of your citrus variety.
5. Sunlight and Temperature Considerations:
This is a frost-damaged orange after a freeze. The fruit after being damaged by a freeze is inedible. For more information on the cold tolerance of different varieties of citrus, see the blog article at this link.
Citrus trees thrive in full sunlight, so choose a location in your yard that receives at least 8 hours of direct sunlight daily. Certain types of citrus also have different levels of cold tolerance, and it may ultimately depend on your elevation or micro-climate as to which types of citrus do well in your yard. In mine, lemons and limes have not done well, but down the hill, friends of mine have bumper crops!
In general though, you will want to monitor freeze risk. If citrus fruit are exposed to temperatures of 28°F for 6 hours or longer over the course of three consecutive days, you will lose your fruit (seriously, frozen citrus fruit is not a pretty sight). In some cases when temperatures dropped to the teens, water froze inside the citrus trees and caused the trunks to split open, killing the tree! This is what smudge pots, grove fans, or other measures have been used for in commercial groves. For frosty nights, consider:
- Covering the tree and other cold susceptible plants with Frost Cloths or old bedsheets
- Be sure to water the tree in advance of a freeze, because soil moisture helps keep the temperature at slightly above freezing for longer
- If you're growing your citrus tree in a container (dwarf citrus varieties do grow well as topiaries or even inside greenhouses or sunny rooms), move it to a sheltered area during extreme weather conditions
Caring for a citrus tree requires a combination of proper pruning, fertilization, and vigilant insect care. By incorporating these tips into your gardening routine, you'll be well on your way to enjoying a bountiful harvest of delicious citrus fruits from your own backyard. Happy gardening!
Disclosure: Just a quick heads-up – when you click on the links to products I talk about, some of them might be affiliate links. That means if you decide to make a purchase, I might get something for sending you their way. It doesn't cost you anything extra, but it helps me keep the tractor running and the fruit trees growing. So, if you find something useful here and wanna give it a go, I appreciate the support.
