Saturday, August 18, 2012

Fruiting Papaya Trees

The process of obtaining fruit from a papaya tree is a relatively long and difficult process if you live in a temperate climate. Due to the papaya's growth patterns and requirements it is almost impossible to grow in temperate climates. This is because papayas typically flower after two years of growth, yet temperate climates get annual freezing temperatures which are lethal for papayas. It is possible to provide cover from light freezes for those in zones 8+ but there is no guarantee of survival. Alternatively you may grow papayas in greenhouses which can provide protection from the winter chill in even lower zones. Heating elements may also be used to grow tropical fruits in just about any freezing climate.

Unless you live in a tropical climate, growing a papaya tree is one major feat, but even more challenging may be harvesting fruit. To set fruit, the papaya must have a sturdy foundation and vigorous growth. I grew my papayas in a raised soil bed allowing for adequate root space. Additionally papayas require a lot of sunshine, water, humidity and nutrients to produce fruit readily. The papayas in my greenhouse went from seed to fruit in about two years, but due to imperfect growth conditions and the size restriction on my greenhouse they yielded small fruits. Papayas typically grow to be over 20 feet tall, but in a backyard greenhouse this is impossible.

A view from inside my greenhouse shows the dominance of my papayas over my other tropical plants. Their rate of growth is truly impressive.
Amazingly, my papaya trees have been fruiting all summer and yet they continue to flower. At first I was hand pollinating the flowers to ensure fertilization, but it seems that they were fertilizing themselves on their own too. Insects and wind can transfer pollen from flower to flower. Just in case hand pollination is required, it is important to distinguish male from female flowers. The easiest way to tell is by the diameter of the flower base, the males are skinny while the female flowers have a larger diameter at their base. This is because inside of the female flowers there is an ovary which makes the flower base bulge. Male flowers have anthers containing pollen required to fertilize the ovary of the female. It is important to note that there are hermaphroditic flowers that contain both an ovary and anthers and thus can self-fertilize but also spread pollen to other females.
These are a few of the papayas on one of my trees right now. I've already harvested some ripe papayas that were about 6 inches long; They were delicious but I found that they didn't ripen evenly.