Carica papaya, or Papaya, is a fast growing, short lived tree native to Tropical America. Trees in nature will reach 25 feet (7.62 m) tall with a very straight trunk. Leaves are dark green and glabrous to 2 feet (0.60 m) across, deeply palmately 7 lobed, with the lobes pinnately lobed. It is widely grown for the edible fruit and for the protein-digesting enzyme, papain, which is extracted from the fruit. Plants are very easy to grow and will produce fruit in about 9 months to a year from planting. They can be grown in the landscape in USDA zone 11.
Blooming: In the greenhouse, trees will bloom in about 9 months from seed. The trees are functionally dioecious and you need both male and female trees to produce fruit. Oddly, there are also plants that produce visually hermaphroditic flowers, like the one shown, but these plants are functionally male. The true females bear flowers on the trunk in axils of leaves on stout peduncles. Individual flowers resemble Plumaria flowers, only smaller, with female flowers reaching 1 inch (2.54 cm) across and 2 inches (5 cm) long and are very fragrant. Males are smaller and borne in clusters in the axils or on racemes.
Culture: Carica papaya need full sun to light shade, with a rich well-drained soil mix. In the greenhouse, we use a soil mix consisting of 2 parts peat moss to 1 part loam to 2 parts coarse sand. To this mix we add 14-14-14 Osmocote slow release fertilizer to every 0.01 cubic yards of soil mix. The plants are well watered and allowed to dry slightly between waterings. Keeping the plants too moist will cause root rot. We fertilize the plants monthly to keep up with the rapid growth using a balanced fertilizer. Due to the fast growth of the plants, it is best to transplant from the seedling stage into a fairly large container to start with. Plants will reach up to 10 feet (3 m) tall if grown in 5 gallon containers. Every couple of years, we start new plants and discard old plants. During the winter months, plants need remain on the dry side and fertilizer is used every other month during this period.
Propagation: Carica papaya is best propagated from seed. Seed obtain from the fruit will germinate in 14-21 days after sowing. You must clean all the fruit from the seed or it will not germinate.
Carica papaya was featured as Plant of the Week July 27-August 2, 2007.
Guide to Past Plants-of-the-Week:
Cal's Plant of the Week was provided as a service by the University of Oklahoma Department of Microbiology & Plant Biology and specifically the late Cal Lemke, who used to be OU's botany greenhouse grower and an avid gardener at home as well. If the above links don't work, then try the overview site. You may also like to look at the thumbnail index. ©1998-2012 All rights reserved.