Imagine strolling out into your own citrus grove in winter, if you will, with an intoxicating aroma of just-ripened oranges and lemons. With a greenhouse, this dream could be a reality-nonthreateningly enjoy the luxury of fresh, homegrown citrus throughout the year. Here is a comprehensive guide to practical tips for successful greenhouse citrus growing that will make your greenhouse transform into a valuable indoor citrus garden even in the coldest climates.
Why Choose Greenhouse Citrus Growing?
The allure of growing citrus year-round extends beyond the simple pleasure of gardening. If you have ever gone to a supermarket during winter, you may be surprised by the prices of some varieties of premium citrus fruits. In growing these plants yourself, the money shall be saved because you will take advantage of every fruit produced without the added costs.
Plus, there’s a potential for year-round income by growing out-of-season fruits. Interest in citrus greenhouse gardening is growing at increasing rates. Grocers and markets are becoming increasingly interested in acquiring unusual, non-native fruits year-round. And because greenhouse vegetable plants are reaching stratospheric heights in terms of desirability, ornamental plants, and tree growers are also starting to take a small interest in growing tropical citrus. It’s a good time to take on this rewarding gardening project.
Choosing the Right Citrus Types for Your Greenhouse
If you're interested in year-round citrus, you must be prepared to maintain and fulfill the specific requirements of the species you wish to grow. You must carefully choose the type of citrus you wish to grow and make sure the particular species of citrus are suited to your location's climate.
The most popular types of citrus grown in greenhouses are lemons, Mexican limes, kumquats, mandarins, and calamondins. Lemons and limes are most often requested by the commercial grower/grocer since the supply of these types of fruits can never keep pace with the demand for the fruit available to order from. Some of the less common or 'niche' citrus types include yuzu, sudachi, and labyrinth pomelos. It will be important to understand these varieties for the grower/operator who plans to anticipate a market for these niche citrus in order to better market them to those consumers who appreciate 'exotic' type fruits.
Citrus Tree Care in the Greenhouse
Care for citrus trees in a greenhouse must find a balance between creating an ideal environment for the plant and not babying it. It pays off when you are particularly attentive to irrigation, fertilization, pruning, and pests by yielding a healthy tree, peak fruit production, and a successful indoor citrus garden.
Watering and Feeding
Citrus trees like to have consistently moist soil but never waterlogged. Overwatering is one of the most common mistakes with container citrus growing and can lead to root rot, a possibly lethal condition. Check moisture in the potting mix by inserting your finger into it an inch deep before watering, and water deeply once it feels dry, letting excess drain from the bottom of the pot. Avoid complete drying of the soil; this stresses the trees, impacting production. During the growing season, spring and summer, feed them regularly with a balanced citrus fertilizer specifically blended for containerized plants. This would include micronutrients such as nitrogen, phosphorus, and potassium but also other elements that are essential to vigorous growth and heavy fruiting.
Pollination
Simply because of the enclosed nature, natural pollinators like bees will not be around, and most of the time, fruit sets may need to be hand-pollinated. When your citrus trees bloom, take a small, soft-bristled paintbrush and carefully collect the pollen from the anthers of one flower - that is the part that bears the pollen. Do this by transferring the pollen onto the part of another flower that is receptive to stigma on the same tree or another, if you have other varieties. Repeat for a large number on each tree to ensure adequate citrus tree pollination. This simple yet important action will increase the likelihood of successful fruit development enormously.
Pruning and Shaping
Pruning and shaping are necessary aspects of care, not only in winter but also throughout the year, especially when dwarf citrus trees are in containers. This helps to keep the size compact and manageable, allows air to circulate inside the canopy, and permits inner branches to receive light for healthy growth and to prevent fungal diseases. Pruning can also be used selectively to shape the tree into a more desirable form.
Special Care in Winter
With the cooling weather and shorter daylight, your winter citrus trees have a natural slowdown and enter a period of relative dormancy. Adjust care to accommodate the cycle in nature. You can decrease the frequency of watering since your trees need less water during the cold months. Stop fertilizing until growing resumes in spring. Keeping the inside of the greenhouse just a little cooler during winter months, about 55-60°F at night, will rest the trees and spring them into heavier bloom. Still, protect your trees from frost and freezing temperatures that might cause damage to foliage and fruits.
Pest and Disease Management
The best pest and disease deterrent is a clean and tidy indoor citrus garden. Regularly clean up fallen leaves, debris, and decaying fruit to minimize insect breeding sites and fungal pathogen inoculum. Keep frequent inspections of your trees for signs of pest populations, such as aphids, scales, mealybugs, and spider mites. If you find any, apply insecticidal soap neem oil, or other recommended organic control methods without delay.
When to Harvest Your Greenhouse Citrus
Harvest time is the happy end to your greenhouse citrus growing effort. Knowing when and how to pick your citrus will ensure optimum flavor and maximize its keeping life.The thing that differs in citrus fruits from most fruits is that they don't continue to ripen after picking. This fact makes picking at the peak of their ripeness extremely important to get the fullest flavor and sweetness. The timing will vary with the cultivar and conditions inside the greenhouse, but there are several critical indicators for ripeness:- Color: Generally, although not always, ripe fruits of citrus display their characteristic bright color - the deep orange of the navel orange, the bright yellow of a lemon, and the deep green of the lime. Note that some varieties, like limes, maybe green but still ripe.
- Feel: Gently press the fruit in your indoor citrus garden. The fruit should be slightly yielding to pressure when it is ripe and full of juice. Avoid fruits with firm or hard feelings.
- Smell: You may sniff the citrus fruit near the stem end; a strong citrus aroma indicates that the fruit is indeed ripe.
- Taste Test: When all else fails, it is down to a taste test in your indoor citrus garden. Select a fruit and taste it if you still are in doubt. If the flavor is sweet and tart, then all other fruits on this tree will be ready for harvest.
How to Harvest Your Greenhouse Citrus
Proper methods of harvesting prevent the fruits from getting damaged and reduce the possibility of diseases. Steps to follow:- Sharp Pruning Shears: Never pull the fruits from the branches, as doing so can damage the tree, putting it at risk from diseases. This should be done with the help of sharp pruning shears that cut the fruit from the branch, leaving a small piece of stem attached to the fruit.
- Harvest in Stages: You need not be in a hurry to harvest the fruits in your indoor citrus garden all at once. Citrus fruits normally ripen in stages, and you can always harvest them in that manner as they reach maturity. This will extend the period of enjoying fresh citrus fruits over a longer period.
- Post-Harvest Storage: After harvest, citrus generally keep best in a cool location with good air circulation. Some types may be kept at room temperature for several days and others refrigerated and stored for up to several weeks.
Conclusion
Greenhouse citrus growing offers a special chance to experience fresh, homegrown fruit whatever the time of year or climate may be. From the financial savings and superior taste to the satisfaction derived from growing your indoor citrus garden, there is little to be said against trying it. Now, take up the challenge of cold climate citrus growing and let your greenhouse turn into a fragrant oasis of citrus delights.
