Collier

Collier is a Morus alba by Morus rubra hybrid in the same northern-selection tradition as Illinois Everbearing, and it is usually grown alongside it rather than instead of it, because the two ripen at different times. Collier comes in roughly two weeks earlier and finishes its crop over a much shorter, more concentrated window, which makes it the practical choice for anyone who wants a quantity of fruit at once for preserves, fruit leather or freezing rather than a long trickle of handfuls. California Rare Fruit Growers lists it as a highly productive hybrid with sweet, lightly tart purplish-black fruit. It is rated to Zone 4, forms a dense round-topped tree, grows quickly even in poor soil and is among the last trees in the garden to leaf out in spring, which incidentally helps it dodge late frosts. Fedco Seeds and Planting Justice both carry it.