Hamilton Nature Notes: Our Largest Native Fruit

By: Ash Lloyd, EcoHouse Green Gardening Volunteer

The Pawpaw

Incorporating native plants into our gardens is becoming more and more popular as the general public becomes more educated about helping ecological issues, like increasing biodiversity and ensuring food source for wildlife. With this in mind, I would like to draw your attention to a native tree fruit that you may not know and is not found in your local produce aisle: the Pawpaw!

What is it?

The Pawpaw (Asimina triloba) is a small native understory tree that produces delicious, large yellow – brown fruit every fall. Their fruit is described as having a sweet, custard-ish flavour; similar to a mango or a pineapple, yet distinct to the pawpaw. You may be wondering why you have not heard of the pawpaw before, the reason being that their fruit does not make a very good commodity. It is only available for a few weeks in early fall and the fruits do not travel well – bruising easily and spoiling after a week or two. Also, the plant loves shade and does not thrive in traditional field-sized orchards the same as other fruit trees, such as apples, oranges, or plums.

How can you grow Pawpaw tree?

Pawpaws typically only grow from fresh seeds, which cannot dry out or else they will lose their viability. The best way to grow pawpaws yourself is to do one of the following: either purchase some seedlings from a local grower or nursery, or grow your own from seed. The best way to get good seeds is to eat some pawpaw fruit and save the seeds immediately after. Seeds need to be planted in some pots filled with a moist rich soil or substrate. Over the winter, the seed will be stratified. As long as the seeds did not freeze or dry out during the winter, your pawpaw seeds should sprout in the spring!

Where to plant them?

Pawpaw trees prefer a moist, fertile soil that is slightly acidic and well drained. You can ensure that your saplings have an ideal growing location by mixing a thick layer of compost into your soil and checking the pH, adjusting the amount compost if needed. Pawpaw trees form colonies when grown in optimal conditions and enjoy the shelter of a forest understory. They can also be grown out in the open as long as they have shelter from strong winds and excess sunlight.

How to get the tree to fruit?

It can be tricky to get Pawpaws to fruit, as they are not self-pollinating and need at least two trees of different genetic origin. The tree’s flowers are small and brown with a yeasty smell that usually attracts small flies or similar insects to pollinate them. To get a good, regular crop it is common for people to pollinate the trees by hand as the tree’s natural pollinators are not particularly abundant or efficient.

Where can you see one?

Here at Green Venture we are lucky to have a small number of Pawpaws growing on the property! You can see for yourself during the warmer part of the year. None of the trees have developed to the size where they produce fruits and flowers yet, but we are likely only a few years away. We hope to introduce visitors to its wonderful fruit some time in the near future.

Sources

Photo 4: “EcoHouse Pawpaw Trees” by Green Venture 2019