February 20, 1998
The various members of the genus Vaccinium are some of the most valuable shrubs for the edible garden. Not only are they widely adapted, but in addition this family (not speaking botanically!) encompasses some of the most attractive edible plants. Even bottom-line gardeners should be pleased with them, since their fruit is relatively pricey when purchased at the grocery store.
Some of the more popular members of this genus are blueberries (V. corymbosum), huckleberries (V. ovatum and V. parvifolium, along with some hybrids), lingonberries (V. vitis-idaea), and cranberries (V. macrocarpon). Of course, there are lots of mainly ornamental members of this family too; I couldn't live in the maritime Pacific Northwest without at least mentioning that in passing! Culturally, all of these plants have much in common.
All Vaccinium prefer quite acid soil. They really need a pH below 5.8, and most will thrive best if you can drop that below 5.0! Since peat moss is quite acid, it has been the material of choice when constructing new blueberry beds. Unfortunately, there are some growing concerns about the wisdom of harvesting the earth's remaining peat bogs. Because of this I am experimenting with using spent coffee grounds as an alternative acidic material for a new blueberry bed; we'll see if it's worthwhile to recommend. Certainly there's no shortage of them, especially up here in the espresso capitol of the world!
These plants all like a moist soil. They prefer it to be well-drained, but can usually tolerate a poorly drained winter situation, as long as summer conditions improve. A highly organic soil is the easiest way to maintain these conditions, since humus has an incredible capacity for holding water. An organic mulch is a good idea – it helps retain moisture, keeps surface organic content high, and protects the rather shallow roots of these plants.
Because this genus is shallow-rooted, you really need to be careful about cultivation around the plant. Don't use the rototiller to control weeds in the blueberry bed! Instead, weed by hand or with a hoe, and let a good mulch do most of the weed control.
Hardiness does tend to vary from variety to variety, so it really is worth checking before you buy. If you live in a warm climate, shop carefully for types that require less winter chill, such as Rabbiteye blueberries (V. ashei). Gardeners in USDA zones 6-8 can pretty much take their pick of any variety. Most evergreen types of huckleberries are much less hardy than the deciduous huckleberries and blueberries. Cranberries and lingonberries, both of which are evergreen, do not follow this pattern – they are listed as being hardy to zone 3, although that is somewhat misleading since their tops can be severely damaged by temps much below 10F, unless they are well-protected.
Pruning is pretty simple. Young plants don't need pruning, although they will do better if they are not allowed to set fruit for the first year or two (so "prune" off the flowers as they appear). These plants tend to maintain a good shape on their own, so you mainly need to just remove older, less-productive wood.
Fertilizer requirements tend to be light. Nitrogen can be provided organically with cottonseed meal (pull the mulch back, and rake the seed meal gently into the top inch of soil), or chemically using ammonium sulfate; both of these are good, acidic, nitrogen sources. A soil test, or just careful observation of your plants, can reveal if you need to provide phosphorus, potassium, or other nutrients.
A final piece of advice: If you want to eat the berries from these plants yourself, it is highly advisable to purchase ¾" bird netting! I have yet to harvest a single berry from any plant that was unprotected.
All contents © Travis Saling
This page was last updated November 18, 2013