Orange trees are pretty to grow and what's more, by planting them in a greenhouse you will have access to fresh vitamin C and delicious citrus flavour right at your fingertips any time of the year. Oranges are a favourite citrus of many and are seen as a symbol of love in Greek mythology. The shiny green leaves which sprout from a citrus seedling are started in a small pot and will grow full and lush with minimal care. Whether you wish to grow California oranges or Florida oranges, use these steps as a guide.
- Skill level:
- Moderately Easy
Things you need
- Growing pots
- Rich Soil
- Spray Bottle
Decide what variety of orange you want to grow in your greenhouse. You may wish to order seeds of a particular variety or plant the seeds from an orange that has fallen out of a nearby orange tree. There is no better way to find what variety you like best than to experiment with growing different seeds. By growing them in a greenhouse you can experiment with growing different types any time of the year and can keep all your seeds, soil and pots in a temperature controlled area conducive to repotting.
Fill medium-sized pots with good drainage holes in their bottoms with rich soil. Use soil with a good amount of humus and add a large handful of clean sand to each pot that is about 10 inches in diameter.
Water the loosely packed soil before planting your seeds. Plant your seeds at least an inch below the surface of the soil. If using small starter pots, one seed in a 2-inch pot is fine. If you are using larger pots you may plant up to five or six seeds in a 10-inch pot but be sure to give them each their own space. These will need to be transplanted into singular pots later.
Place the potted orange seeds in a sunny part of the greenhouse. If it is dim then use a grow light or a 100 watt bulb overhead, no closer than 3 feet above for four hours a day. Make sure that the temperature does not fall below 4.44 degrees Celsius in the greenhouse. Usually this is no problem due the translucent structure of greenhouses; they allow the sun to naturally warm the entire enclosure. However if you live in an extra cold zone then placing a space heater in a corner of your greenhouse without plants can give your plants the extra boost they need. Citruses prefer a temperature of at least 10 degrees C.
Keep soil moist while seeds are germinating with the water-filled spray bottle. They should sprout within three to four weeks. Greenhouses are the ideal place to grow citrus indoors because they naturally collect condensation. If you are lucky enough to have a greenhouse equipped with sprayers from the ceiling that go off on a timer then these are quite useful too.
Water the plants but do not let the roots sit in standing water. Let the leaves grow for at least six months before you start to trim any of them.
Transplant any seedlings that have sprouted in tiny pots to larger ones when the roots are strong enough to be moved and are branching out nearly as wide as the pot. This can be done right in the greenhouse. Waiting six months is an adequate amount of time. Orange trees can grow from 8 to 25 feet high depending on the variety and growing conditions. Depending on how high your greenhouse is you may need to keep them at a certain height once full grown by pruning and trimming though orange trees do not need much pruning. Once trees are established they grow best in large tubs.
Rotate your plants from time to time if you keep grow lights in your greenhouse during the winter that are on one distinct side of the plants. The plants will grow to lean towards the light source, so turning them keeps them even. Clusters of four to six white flowers will bloom prior to the growth of fruit.