Note that some varieties of orange are seedless. Ask a fruit seller for a variety with seeds.

There is no need to dry the seeds afterwards. Keeping them moist will make them more likely to sprout.

If you are using seeds that have dried out, they are in a dormant state and can take months to germinate, or fail to do so at all. [2] X Research source Professional orange growers soak some slow-germinating orange varieties in gibberellic acid before planting to speed up the germination even more. This is typically unnecessary for a home project involving a handful of seeds, and can easily backfire if the wrong amount is used for your orange variety.

Remember to put a plate or other object underneath the pot to catch the draining water. If the soil is poor at draining, mix in hardwood bark chips. This makes the soil less compact, which lets water drain through faster. [6] X Research source

Stop adding fertilizer once the plant has grown into a young tree. Follow the instructions for a Seedling or Young Tree instead. It shouldn’t need additional fertilizing until its second year.

The best time to re-pot your orange tree is in the spring, before it has put a lot of energy into growing. [11] X Research source Cut off any dead or broken roots before planting. [12] X Research source First sterilize the knife by boiling it or rubbing it with alcohol to reduce the chance of transmitting disease to the tree. Pack the soil gently around the roots to remove pockets of air. The top roots should end up just under the surface of the soil.

Choose an area protected from the wind. To allow for root growth, plant standard-sized orange trees at least 12 feet (3. 7 m) (3. 7m) from walls and other large obstacles, and 25 feet (7. 6 m) from other trees. [13] X Research source If using dwarf orange trees, look up your variety’s requirements. The trunk itself can grow to be 10 feet (3m) wide. Plant the tree at least 5 feet (1. 5m) from foot paths to keep them clear.

Do not cover the trunk with soil, or the orange tree could die.

If your adult tree is exposed to too high temperatures, hang a sun shade or sheet over the tree until the temperature decreases below 100ºF (38ºC). Move your orange tree indoors before a frost occurs. Citrus trees are more vulnerable to frost than heat, although some varieties may be able to survive a mild period of frost.

Typically, the tree can be watered once to twice a week, but this varies depending on temperature, humidity, and amount of sunlight received. Use your judgement and water more regularly during hot, dry seasons, although you should generally avoid watering plants while the sun is high in the sky. If your tap water is hard (mineral-heavy, leaving white scale on kettles or pipes), use filtered water or rainwater instead to water orange trees. [17] X Research source

Young trees 2–3 years old should have two tablespoons (30mL) of nitrogen-high fertilizer spread under the tree 3 or 4 times a year, immediately before watering. Alternatively, mix one gallon (4L) of high quality composted manure into the soil, but only in the fall when rains can wash away excess salts before they cause damage. Adult trees 4 years or older grown outside require 1–1. 5 lb. (0. 45–0. 68 kg) of nitrogen a year. Your fertilizer should say what percentage of nitrogen it contains, which will allow you to calculate how much fertilizer you need to use to achieve the correct amount of nitrogen. Scatter over the root area of the tree and water into the soil, either annually during the winter or in three equal batches in February, July, and September.

Too much manure fertilizer, or manure applied during the dry season, can be a cause of alkalinity.

Healthy adult orange trees will rarely die due to frost, but they can experience leaf damage. Wait until spring to see which branches survive before pruning the dead ones off.