Nanking Cherry

While the bush is still dormant, take out 3 to 5 of the oldest canes near the ground, then remove dead and damaged wood, crossing branches, and old center limbs to open the middle up. Leave the young wood alone. Flowers form on one-year-old and older growth, so a rolling supply of young canes is what carries the crop, and an open center lets this very twiggy shrub dry quickly after rain, which is the cheapest control you have for blight and branch canker.

Set two or more Nanking cherries near each other in full sun. Seedlings raised from different parents, or two different named strains, will pollinate each other. Nanking cherry requires cross pollination and must have two or more plants in the area, so a lone bush flowers beautifully and sets almost nothing. This is the single most common reason a healthy-looking planting never fruits.

If the bush carried shothole lesions or twig cankers last season, spray chlorothalonil once the petals have fallen. A bush with clean wood does not need this spray. Coryneum spores need about four hours of standing water on a leaf or twig to germinate and infect, and 70 to 80 F is their optimum, so the soft new tissue expanding into wet spring weather right after petal fall is exactly what they colonize first.

In hot dry weather, tap a branch over a sheet of white paper and look for moving specks, and check the undersides of leaves for fine stippling and webbing. If mites are present, treat with insecticidal soap or a 1 percent horticultural mineral oil every 5 to 7 days. Spider mites build up fastest on hot, dry, dusty foliage, and they breed quickly enough that one application only kills what is currently hatched - the 5 to 7 day repeat is what catches the next generation and actually breaks the cycle.

When the cherries in the sunniest part of the bush first turn a salmon blush over the yellow, spray spinosad and repeat every 7 to 10 days until the crop is picked. Malathion is the conventional alternative, also on a 7 to 10 day interval — USU advises the 7-day end, so tighten toward 7 days in warm weather or after rain. The female lays her eggs into the fruit as soon as it begins to color, and once the maggot is inside the cherry no spray can reach it, so the entire program is about killing adult flies in the few days before they lay.

Go over the bush every day or two as the fruit colors, taking the deep red cherries that give slightly to the finger. Chill or process them the day you pick. The fruit is very soft at peak ripeness and has a very short shelf life, so the gap between perfectly ripe and mush is a couple of days, and the birds are working the same window you are.

Once about half the leaves have dropped, and before the heavy autumn rains arrive, spray a fixed copper product over the whole bush and cover the twigs thoroughly. Rake up and destroy the fallen leaves and prune out cankered twigs while you are at it. The fungus overwinters in dormant leaf buds, blossom buds and small twig cankers, and it infects through the fresh scars each falling leaf leaves behind, so copper on those scars is what stops the carry-over into next season. Bud and twig lesions can keep producing spores for two or three years if you let them stand.

Before the ground freezes, wrap hardware cloth or a wire cage around the base of the bush and pull mulch and long grass back away from the canes. Nanking cherry is browsed by rabbits, mice and deer, and that browsing can cause serious injury if no control measures are taken - the canes are thin enough that a winter of chewing at the base kills whole stems outright.