Blueberries are wonderful plants. Not only do they live for
decades and bear delicious fruits that are need almost no care, but they also
are beautiful in themselves, with white, bell like flowers in spring and hand
some oval leaves that turn orange scarlet in fall. The berries are pretty, ripening
slowly so that clusters are green, red and blue all at once. Even the bare
reddish stems are eye-catching in winter. I often use blueberries in
landscaping a home whether the owners want to eat the berries or not if they
don’t certainly the birds will. The plants look good as hedges, at the edge of
a pond or even near the house as specimen shrubs.
There’re many different blueberry species. The one most
commonly grown for fruit and for ornament is high bush blueberry (vaccinium
corymbosum). It is hardiest of the lot and usually grows to about eight feet
tall if unpruned but sometimes twice that. Low bush blueberry (V.
angustifolium) stays under two feet tall and makes a fine ground cover.
Rabbit-eye blueberry (v.ashei) is highbush species that unlike V.corymbosum,
does not need to be thoroughly chilled in winter and will bear will in the
south. It does not thrive north of Zone 7. V.ashei is a very tall, vigorous
shrub that ripens later than northern blueberries; the fruits are generally not
as sweet but are large and good for baking. In Connecticut, both highbush and
lowbush blueberries grow wild. The wild berries are best of all if you judge by
flavor, even though they’re smaller and picking a pie, may take hours. But what
better way to spend a few summer hours on a sun baked hillside. The next question
is to select the site for blueberry.
Select a Site
Selecting a blueberry site by observing the plants in the
wild can be misleading. The highbush ones often grow in swamps, and while it
may look as if they’re growing with their feet in the water, they’re actually
perched above it, with the ground they grow in soaking up water from below. The
lowbush blueberries appear to scramble over bare, rocky mountaintops where
there seems to be hardly any soil at all, let alone water. But their long roots
are actually snaking down into fissures in the rocks, finding both. The roots
of both highbush and lowbush blueberries spread vigorously underground. You
should give your blueberries a site where moisture is ample but doesn’t just
sit around the roots. Other important factors are full sun so they’ll ripen,
and good air circulation to prevent disease.
Select a Soil
Soil should be loose and light but the most important factor
in growing blueberries is acidity. Blueberries like a pH of about 4.5 and will
grow in anything from 3.5 to 5.5. If you’re not sure whether the soil is acid
enough in your area or in the spot where you want to grow them, has it tested.
If the soil is alkaline you may want to grow something else instead, but if you’re
hell bent on blueberries there’re ways to make your soil more acid. You can add
aluminum sulfate purchased from a garden center, following the directions on
the package or the recommendations of your soil test, but in most cases you can
lower pH simply by digging a lot of acidic organic matter into the soil; rotted
leaves, wood chips, peat moss, shredded bark, sawdust any of these will do the
trick and will also help the soil to retain the moisture that blueberries need.
Planting Blueberry
Buy dormant plants that are two or three years old those any
older are difficult to transplant. You can order them by mail or pick them up
locally. Planting bare root is fine and gives you a chance to see whether the
plants have a good, healthy, fibrous root system rather than just a few stringy
roots. But be sure to keep the roots moist up until the time they go into the
ground this is extremely crucial.
Planting blueberries in early spring in cool climates, late
fall in mild ones; in holes 18 inches deep and equally wide, well enriched with
organic matter. If the planting area has poor soil, enrich it throughout. Don’t
add fertilizer or manure directly to the hole, however, though you may spread
some on the soil surface. Especially for rabbit eyes so the whole bush can be
sun ripened but if you are making a hedge, and then three to four feet apart is
acceptable. Dwarf highbush varieties can also go this close, or they can be
planted in containers. Well, plant lowbush berries about two feet apart. These
can be dug from the wild if you have a source, by removing large pieces of sod
along with the bushes. Though planting blueberries at the same depth at which
they were growing previously or an inch or so deeper, spreading the roots out
in the soil, firming lightly and watering well. Cut back the tops by half and
apply a thick mulch almost six inches is about right of an acidic organic
material such as shredded bark.
Growing
It is very important to keep the plants moist the first year
they’re growing and any time that fruit is forming. They should be fed fairly
heavily each year at blossom time by top dressing with acidic compost, well-rotted
manure, or a commercial fertilizer designed for acid loving plants such as
azaleas. You can also use cottonseed meal, blood meal, fish meal, ammonium
sulfate, rock phosphate, bone meal or just about anything else you like except materials
such as a wood ashes or lime, that will raise the pH. And don’t fertilize
excessively with nitrogen or you may get vigorous plants with sparse fruit. However;
you can feed again as fruits are forming, but don’t feed past June in climates
where late new growth may be winterkilled. Don’t try to dig fertilizers into
the soil since the plants are shallow rooted; just remove the mulch, apply
nutrient to the soil surface, water well, and replace the mulch. The mulch will
break down and do its part in acidifying and lightening the soil; add some more
each year.
Well, blueberries especially highbush species, benefits from
pruning to keep the plants a size you can pick easily to let sun into the bush to
ripen fruits and to keep a good supply of fresh new growth coming along.
Berries develop on fruiting spurs produced the previous season on side branches
of old main stems. You perhaps won’t have to start pruning until bushes are
three to four years old, but make sure then start thinning them once a year while
they are dormant. Just when they are about to leaf out is a good time because
you can then remove any winterkilled wood. Thin out old, gray canes with lots
of little twigs that have grown beyond bearing age and have no fruiting buds
visible, cutting them at the base of the plant. Favor the newer, redder canes,
keeping 6 to 8 good bearing canes on the bush. Tall, straggly canes can be
headed back, and weak, short, twiggy growth can be removed from tips. Note,
while pruning, that fruiting buds are fatter than leaf buds; avoid removing twigs
with a lot of these.
Pets and Disease
If you buy healthy bushes and take good care of them you will
probably have very little trouble with blueberries. There’re some diseases, but
most modern cultivars have been bred for resistance. If you live in an area
where the berries are more disease prone, apply fresh mulch each year, prune
out debris promptly disinfecting your clippers between cuts and go easy on the fertilizer.
If bushes succumb to botrytis in wet weather the berries shrivel and the tips
die or stunt diseases which are spread by leafhoppers and stunt the plants,
destroy them and start over in a new place. They might occasionally get yellows
disease if drainage is poor and the pH too high. Mummy berry, a fungus that
makes the berries shrivel and harden is often caused by wet weather and poor
air circulation. Remove all debris, especially dead berries hold off on fertilizer
and turn over or replace the mulch in early spring.
The most troublesome pests of blueberries you’ll perhaps have
to cover the bushes with plastic netting or cheesecloth extending clear down to
the ground to avoid losing much of your crop. Spreading the netting on a light
weight metal or wooden frame work with a flap you can lift to enter the cage
will make picking easier. Other pests include blueberry maggot the larva of the
blueberry fruit fly, which enters the fruit and rots it. Clean up dropped
berries and fight the critter by catching it in the fly stage with yellow
sticky traps or by using rotenone. If blueberry stem borers get into the stems
in early summer, causing them to wilt, remove the stems and burn them. Pick off
Japanese beetles or use milky spore disease.
Harvest
If you can bring yourself to do it, you should rub off
developing berries on young plants until they’re three to four years old, to
let the bush put its energy into growth. You’ll start to get abundant crops
when the bushes are about five years old probably about six quarts per bush.
You should pick at least twice a week, just rubbing your thumb over the berry
cluster and letting the ripe berries that look blue are not always ripe. They
should really sit on the bush for a week after they are blue, until they fall
off easily. The fact that the clusters ripen a little at a time means that you
can pick from a single cluster for up to a month and enjoy the berries over a
long period. However if you plant early, middle and late varieties you can harvest
berries from June to September.
Varieties
Most blueberry varieties do not self-pollinate well, so it is
best to plant several. Though popular early varieties include “Earliblue” the
short growing “Northland” and “Collins” which bears in long, uniformly ripening
clusters For midseason grown “Blueray” “Bluecrop”
and “Berkeley” all of which bear abundant crops of large berries. For later
berries grow “Jersey” the shrub is especially handsome, the sweet, dark “Herbert”
and to wind up the season, “Coville”. Good varieties for the north are “Northland”
“Eariblue” Blueray the early “Patriot” the late bearing “Elliott and “Northblue”
which is a self fertile dwarf variety. Tophat is a hardy dwarf that can be
grown in tubs. For rabbit eye varieties the standard favorite is “Tifblue”, a
vigorous, upright bush that bears fairly late. For an early one try “Climax” or
the lower growing “Woodward”. Moreover for midseason try the compact “Southland”
and for late seson the sweet-tasting “Delite”.
