🍈 Whitman Fiberless Soursop

What it looks like

Why this variety

Whitman Fiberless is the soursop for Florida growers who want a local legend: a Florida selection, named for Bill Whitman, the Miami fruit pioneer, and sold grafted by South Florida nurseries, with large fruit and sweet, fiberless flesh that tasters describe as pineapple-like, with notes of apple, mango, banana, and passion fruit combined. It is the soursop that Florida rare-fruit growers trade and treasure, the one whose first harvests from grafted trees are reported with the kind of excitement usually reserved for new mango cultivars, and its sweetness — described as the sweetest soursop some tasters have ever eaten — is the reason. If you want soursop as a Florida fruit, not just a tropical one, Whitman Fiberless is the one to plant.

The trade-off is the same as all soursop, with one naming caution: Whitman Fiberless is sold grafted, and grafted trees fruit sooner and truer than seedlings, so buy grafted stock from a reputable South Florida nursery and do not trust a seedling labeled with the name. Give it full sun, well-drained soil, and steady water, protect it from cold wind, and pick fruit when it softens on the tree, eating it promptly. In Florida, Whitman Fiberless belongs in South Florida ground only, and its sweet, pineapple-like fruit is the reward for buying the real grafted tree and giving it the warmth it needs.

If you are new to choosing between cultivars, the Varieties Matter guide explains why the name after the plant matters as much as the plant itself. Whitman Fiberless is a perfect example: it is not just a soursop in the abstract, it is a soursop with a specific job, a specific history, and specific strengths.

Florida honesty: soursop is a South Florida fruit, and Whitman Fiberless, as a Homestead-nursery selection, is the most Florida of the three — but it is still a zone 10 to 11 tree with no frost tolerance. In South Florida, plant it in full sun and well-drained soil, water steadily, and buy grafted stock. Elsewhere in Florida, do not plant it in the ground. Whitman Fiberless is a South Florida treasure, and treasures that need frost-free warmth should be planted where frost does not come, which is the whole honest story.

How to grow

Plant a grafted tree in spring, in full sun and well-drained, moderately rich soil — soursop wants warmth, sun, and drainage, and it has no frost tolerance at all. Work worm castings and compost into a wide planting hole, stake for the first year or two, mulch thickly, and space for a tree 15 to 25 feet tall. Protect young trees from cold wind, water deeply at planting, and do not plant soursop where frost comes, because a single hard freeze can kill it to the ground. Prune lightly to keep it at picking height, because a soursop picked from a ladder is a soursop dropped.

Set plants 15-20 feet apart in soil with a pH around 6.0-7.0. Work worm castings into the bed at planting and mulch to hold moisture. A well-fed soursop plant rewards that care directly: steadier growth, better bloom, and a show that actually shows up.

Water & feeding

Water deeply and regularly while fruit develops — soursop wants steady moisture through the growing season, and drought causes fruit drop and small fruit. Water at the soil line, mulch thickly to hold moisture, and feed regularly: castings and compost in spring plus a balanced fruit-tree feed through fruiting. Once established, soursop tolerates short dry spells, but a tree that dries out while fruit swells will drop its crop. In winter, reduce water slightly for trees in cool weather, and do not fertilize a cold-stressed tree.

Common problems

• Frost — kills to the ground; soursop is a tropical tree for frost-free ground, and nowhere else in Florida.
• Fruit picked green — soursop does not ripen well off the tree; pick only when it softens on the tree, or fruit will stay bland and hard.
• Anthracnose and fruit rot in wet weather — improve airflow with light pruning, pick fruit promptly when ripe, and remove rotted fruit from the tree.
• Poor fruit set on seedlings — seedlings vary wildly and often fruit poorly; buy a grafted, named selection for known fruit quality.
• Mealybugs and scale in humid, crowded canopies — prune for airflow, treat with horticultural oil, and encourage predators before spraying.

Harvest

Pick fruit when it softens and yields slightly on the tree, and the skin turns from dark green to a lighter, yellowish-green — soursop picked green stays hard and bland, and soursop picked ripe is soft, fragrant, and custardy. Eat fresh with a spoon, scooping the smooth pulp and discarding seeds, or blend into juices, ice creams, and smoothies, which is how most soursop is enjoyed. Eat promptly, because ripe soursop keeps only a few days, and freeze pulp for later use — a soursop tree in full crop feeds a neighborhood, so share the surplus before it softens past its prime.

Saving seeds

Whitman Fiberless is the soursop for Florida growers who want a local legend: a Florida selection, named for Bill Whitman, the Miami fruit pioneer, and sold grafted by South Florida nurseries, with large fruit and sweet, fiberless flesh that tasters describe as pineapple-like, with notes of apple, mango, banana, and passion fruit combined. It is the soursop that Florida rare-fruit growers trade and treasure, the one whose first harvests from grafted trees are reported with the kind of excitement usually reserved for new mango cultivars. Seed will not repeat it: grafted trees fruit sooner and truer than seedlings, and a seedling is a lottery ticket. Plant a grafted tree in spring, in full sun and well-drained, moderately rich soil, space for a tree 15 to 25 feet tall, and protect it from cold — soursop has no frost tolerance at all, and a single hard freeze can kill it to the ground. The full method is in the Saving seeds section of the Soursop guide.