Malus coronaria Seeds | Sweet Crabapple
LATIN NAME: Malus coronaria
COMMON NAME: Sweet Crabapple
Plant Profile
Sweet crabapple is a small, wide-crowned tree of the eastern North American woodland edge, and it is one of the wild species that gave the cultivated apple its hardness. It usually reaches six to nine metres, with a short trunk that forks low and a crown that spreads wider than it is tall. The twigs are stout and carry short, blunt spurs, and the bark on older wood breaks into small, scaly plates. Leaves are broad, ovate and sharply toothed, with a soft, slightly lobed look; crushed in the hand they smell faintly of apples, a small detail that gives the species away in summer.
The flowers are the reason most people meet it: large, five-petalled, white flushed with pink, intensely fragrant, opening in May across the whole crown at once. Fruit follows in autumn, round, greenish-yellow, two to three centimetres across, and it hangs on the tree well after leaf fall. The fruit is sweeter and less acid than most wild crabapples, which is where the common name comes from, and the flesh is firm enough to make the tree worth picking rather than merely admiring.
Science & Biotechnology
Malus coronaria is interesting to breeders because it is one of the wild North American crabapples that has exchanged genes with the orchard apple wherever the two meet. Populations in old farmland show a spectrum of intermediate forms, and some trees are hard to assign to either parent, which makes the species a live case study in introgression rather than a fixed type.
It is also one of the crabapples used in rootstock and hardy-scion breeding, since it survives winter cold that would injure dessert varieties, and its resistance to some strains of fireblight has been measured in trial plots. The unusually mild fruit is a further point of interest; most wild crabs are sharply acid, and the balance here has been traced to the ratio of malic to quinic acid in the flesh, which is also why the fruit browns slowly when cut.
Uses & Benefits
The fruit is too small and too seedy to eat out of hand, but it is unusually rich in pectin and sets a firm, clear jelly with a flavour closer to quince than to apple. In the eastern states it was a standard preserve fruit in farm kitchens, and it still makes a good sharp jelly and a decent cider when blended with sweeter apples.
The tree itself earns its place as an ornamental: it flowers heavily, it flowers late enough to miss most frosts, and its scent carries a long way on a warm evening. It also feeds wildlife, with fruit that persists into winter and buds that grouse and finches work over in hard weather. As a specimen on a lawn or at the edge of a wood it needs no more than occasional pruning, and it casts light shade rather than the dense shadow of an oak.
Growing from Seed
Seed needs cold and moisture before it will move. Clean the fruit, mix the seed with damp sand in a sealed bag, and hold it at about four degrees Celsius for ten to twelve weeks; a refrigerator is the simplest place. Sow into a deep pot of loam-based compost, cover the seed by its own depth, and keep the pot outdoors from spring so the seedlings grow in natural light. Germination is uneven, spread over six weeks or more, and a proportion of the seed will sit out the first year.
Transplant the seedlings while they are still small, because crabapples make a strong taproot and resent being lifted once it has thickened. Grow them on in a nursery row or a deep pot for two seasons, then plant out in autumn into any reasonable soil in full sun. The first flowers usually appear in the fourth or fifth year, and the first real crop of fruit a year or two after that.
Our Take
A fragrant, cold-hardy crabapple with real garden presence and a useful fruit; worth the wait from seed. Give it sun and a little patience and it will outlive most garden trees.
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