Pawpaws are quite hardy, and strains native to the northern part of their range, from Nebraska through Michigan and into southwestern Ontario, Canada, are able to withstand temperatures down to minus 25. It is doubtful that strains from the Deep South are this hardy.
Pawpaws do not do well in areas that have low humidity, strong winds or cool marine climates. They do best when planted in rich, well-drained soil in a location protected from wind. Pawpaws are normally found in wooded areas and often form dense thickets. Although the pawpaw trees that get the most sun usually produce the most fruit, when the trees are small they should be protected from intense sunlight. Planting them about five to 10 feet from the north side of a house, garage or similar building is often ideal. If you plant pawpaw trees in the open, they should be protected from direct sun for at least the first two years.
You can grow pawpaws from seeds or transplants. Seeds tend to be cheaper. Just plant three to five seeds 1 to 2 inches deep in the fall, in a permanent location. If you wish to plant the seeds in the spring, make
sure they have gone through a 3- to 4-month cold period (stratification) before planting.
The downside with planting pawpaw seeds is that you won’t know a tree’s qualities until it starts bearing fruit. To overcome this, you can choose grafted trees. One grafted variety, Convis, is said to produce pawpaws up to a pound each. Many other varieties are available, but may take some searching to find.
Pawpaws require cross-pollination for fruit set, so plant at least two different varieties for best results. Or, if you plant seeds, plant at least two viable seeds; if you plant grafted varieties, you must plant two different varieties or one grafted pawpaw along with a seedling.
Pawpaw trees normally do not begin bearing fruit until they are 5 years old. However, well-grown grafted varieties sometimes begin bearing earlier.
When planting pawpaw trees, and for subsequent care, follow the normal recommendations for planting any tree or shrub. Here are a few additional tips.
1. Do not neglect to prune the tree after it has been planted. Pruning helps any tree or shrub survive its first year. This is especially important with pawpaws.
2. Water the tree frequently for the first two years. Make sure the soil never dries out, but do not waterlog. With extremely sandy soil, it is nearly impossible to water too much.
3. Water now and then with a bit of soluble fertilizer, such as Miracle-Gro, to help get your pawpaw trees to grow faster and bear fruit earlier.