Gadenin日本語Get the appWater: steady moisture, never standing water
Pawpaw evolved on river terraces where the water table sits close under the surface all summer. It has no drought strategy: the big leaves transpire heavily, and when the soil dries the tree drops fruit first and leaves second. A young tree that dries out badly in its first two summers frequently dies, and an established tree that dries out in midsummer sheds the crop you hand pollinated for.
For a tree in its first two years, water deeply once or twice a week in the absence of rain, giving five to ten gallons (20-40 liters) slowly at the base so it soaks in rather than running off. From year three onward, water when the top three inches (7.5 cm) of soil under the mulch is dry, and prioritize the six weeks when the fruit is sizing up. Container-grown pawpaws need checking daily in summer heat.
The counterpart is drainage. Constantly saturated soil, particularly cold winter soil, rots pawpaw roots, and the symptom is the same yellowing and wilting you get from drought. Before you add more water to a wilting tree, dig down six inches (15 cm) and feel the soil. Wet soil plus a wilting tree means root rot, and more water makes it worse.
Feeding, and the mulch that does most of the work
Pawpaw is not a heavy feeder, but it responds to fertile, humus-rich ground. A balanced fertilizer applied once as growth starts in spring, and again lightly in early summer for a young tree, is enough. Stop all feeding by midsummer so the wood hardens before cold weather. Overfeeding with nitrogen gives lush growth, soft shoots and less fruit.
Mulch matters more than fertilizer. Keep three inches (7.5 cm) of wood chip, shredded leaves or leaf mold over the whole root zone out to the edge of the canopy, topped up annually and kept an inch (2.5 cm) back from the trunk. It holds the even moisture the tree wants, feeds the soil as it breaks down, keeps grass off the surface roots and moderates soil temperature. Grass growing right up to a young pawpaw trunk noticeably slows it down.
On limy ground the tree yellows between the leaf veins. Correct that with sulfur or an acidifying feed rather than more nitrogen, and use acidic mulches such as pine needles or oak leaves.
| Task | When | What to do |
|---|---|---|
| Spring feed | As buds break | Balanced fertilizer over the root zone, watered in |
| Second feed (young trees only) | Early summer | Half rate; none after midsummer |
| Mulch top-up | Spring and autumn | Restore to 3 in (7.5 cm), clear of the trunk |
| Deep watering | Any dry week in growth | 5-10 gal (20-40 L) slowly at the base |
| Sucker removal | Whenever seen | Cut at ground level, do not tear |
| Shade cloth on | Years 1-2, before hot weather | Roughly 50 percent shade on the sunny sides |
| Shade cloth off | Start of year 3 | Remove entirely so the canopy fills |
Suckers and the patch problem
Pawpaw spreads by root suckers, and in the wild a whole thicket is often one clone. In a garden that habit is a nuisance and a trap. A nuisance because suckers appear several feet from the trunk, draw energy from the tree and turn a specimen into a thicket. A trap because those suckers are genetically identical to the parent, so a patch of them can never pollinate itself no matter how many stems it has.
Cut suckers off flush at ground level as soon as you see them, using a spade or pruners. Cutting them at knee height leaves a stub that branches into several new shoots. Do not dig them out for transplanting either: severing the root that feeds them from the parent damages the parent's root system, and detached suckers rarely survive because they have no taproot of their own.
Also remove any growth that appears below the graft union on a grafted tree. That growth is the rootstock, not the selection you bought, and it will outgrow the top if left.
Through the seasons
Pawpaw is fully hardy through winter once established, down to around minus 25F (minus 32C), and needs no wrapping or protection in most temperate gardens. It leafs out late, well after most trees, which protects the flowers from late frosts and also means a bare pawpaw in mid-spring is normal and not a dead one. Do not give up on a leafless tree until well after everything else has flushed.
The one winter vulnerability is the thin bark of a young trunk, which can split from winter sun on cold days. A loose white trunk wrap or a board on the sunny side for the first few winters prevents it. In late summer, expect the leaves to look tired and slightly yellow; the tree turns clear yellow and drops early in autumn, which is normal rather than a deficiency.
Keep a simple log of the date the leaves emerge, the date the flowers open and the date of the first ripe fruit. Pawpaw seasons shift by two or three weeks year to year, and after two or three seasons of notes you will know when to start checking the fruit rather than guessing.