Purchase a mango cultivar, if possible, as they fruit within four or five years, while seedlings take about three years longer. Choose an anthracnose-resistant variety if you live in a humid climate. Wait until a seedling is at least 4 months old before setting it outdoors.
Select a location for your mango cultivar or seedling in full sun and sandy, acidic soil, at least 20 feet from any other trees. Dig a hole 2 feet deep and 2 feet wide, and mix an equal amount of composted manure into your pile of soil. Set the tree in the hole, at the same level it grew in its container, and tamp the soil and compost mix around its roots.
Water the mango well and continue to water it twice a week while it is getting established, with at least 2 gallons at a time. When it is well-established, drop the waterings to once a week -- and only during dry spells.
Fertilize the tree every two months its first year. Start with one-half pound of 5-5-5 organic fertilizer, as young mango trees can be burned by chemical fertilizer. Increase that amount by about one-fourth pound at each feeding. In its second year, feed the tree only three or four times, each time giving it 2 pounds of organic fertilizer per inch of its trunk's diameter. Switch to a higher potash organic fertilizer, such as 4-10-7, in the same amounts once the mango begins blossoming.
Watch for your mango tree to produce clusters of reddish-white flowers, as early as January in the warmest areas of its range or as late as April in cool and foggy coastal conditions. The fruits should mature five months after the tree blooms. Pick mangoes when they are ripe enough that their stems break easily.
Purchase a self-fertile papaya cultivar, as you can't know the gender of seedlings until they bloom. Plant your papaya in rich, well-drained soil in full sun.
Water it well and mulch it with compost, to protect its shallow roots and keep their soil damp. Make sure the papaya receives at least 1 inch of rainfall or other irrigation per week.
Feed your papaya one-fourth cup per month of 10-20-20 granular fertilizer, or about twice as much 4-10-7 organic fertilizer, until the end of its first year. Then give the plant only 1 cup of the fertilizer per year (2 cups organic), after it fruits.
Watch for your fast-growing papaya plant to flower when it is around 6 months old and to produce fruit when it is 9 to 14 months old. Pick those fruits when they have changed color by about 80 percent.