Growing Information
Growing cranberries can be easy and fun. Check out our information below or go to our Cranberry Videos page to see how it is done. Select an area of interest.
"Why Grow Cranberries?
About the Plant What Varieties to Grow How to Purchase Plants When to Plant How to Prepare the Soil Caring for the Cranberry Bed Harvesting Protecting Your Plants for the Winter Other Practices to Keep Your Planting Healthy Pest Control Cranberries in the Home
Why Grow Cranberries? Cranberries are one of the healthiest sources for getting your vitamin C and protecting your body against urinary track infections. More studies are showing other beneficial effects because of their high antioxidant content. Each cup of these little red and tart berries are easy to grow, becoming popular as a health food choice, and render a unique addition to the home garden. About the Plant The cranberry is an evergreen groundcover plant native to North America. Only two other species of fruit are native, the lowbush blueberry and the grape. Cranberries have two types of growth habits; runners (rhizomes) which trail on the ground and spread the plant as long as two feet in one season and uprights which are born on the runners in the second and third year and bear the flowers and fruit. The goal is to get the numerous runners to spread quickly in the first two years to cover the ground, and then to produce strong uprights (up to 200 per sq. foot) to produce flowers and fruit. The cranberry plant has a fine root system that only grows in the upper 4 to 6 inches of the soil. These roots do not have rootlets and depend on mycorrhizal associations to absorb nutrients. The root systems are also very able to withstand long periods under water in the winter, which is a genetic trait of many wetland species. Knowing about the plant and growth habit can help you understand how to grow this uniquely american fruit.
How to Purchase Plants Cranberry plants can be purchased as one year rooted cuttings or three to four year ready-to-fruit plants in 6" pots. Six, 6" pots will plant a 4x8 garden plot, although, the more plants you purchase, the faster you can fill in a bed. One year cuttings will take three to four years to fruit. Three and four year old plants should be ready to flower and fruit in the first season as they have developed numerous uprights. When to Plant Cranberries can be planted in the fall through October and early November or in the spring between April 15th to May 31st. Summer planting of 3 year old rooted plants is also possible, so long as plants are purchased in pots and are actively growing. How to Prepare the Soil
![]() Sandy Soils - If your soil is already sandy remove topsoil down 8 inches, add a
6 mil plastic liner, poke plenty of holes in the plastic, and add 4 bales (3.8 cu.ft) of peat moss
for every 32 square feet. Mix in bone meal (1/2 lb), epsom salts (1 cup), rock phosphate (1 lb) and bloodmeal (1 lb) for
every 32 sq. ft. Wet peatmoss with garden hose, or wait until natural rain moistens the peat. Wetting
the peatmoss will be hard. Be patient and add water in a mist, slowly. Mix the pet often to help absorb water. Clay or Silt Soils - If your soil is clay or silty, dig out a garden area 8 inches deep, directly add the peat without the plastic liner. Follow directions as above for adding peatmoss, fertilizer and water. Cranberry beds do well with a formal wood or plastic border around the planting. Raised beds can also be done so that you can
contain the runners as the plants fill out the bed. The goal is to keep weeds from invading the bed, or for the cranberry
plants to overtake the lawn.
![]() When planting, space one year plants, like those from other catalog companies, 1 ft x 1 ft, or closer, with root ball two inches below surface. For Cranberry Creation's plants in six inch pots, plant them about 2.5 ft x 2.5 ft apart.
It bears repeating here that flowers and fruits form on the uprights. Uprights form at the nodes of the runners. Once the bed is filled in with runners, which takes about two years, then you want to start to form uprights. You need to withhold nitrogen, and IF the runners are inhibited from growing strongly they will produce uprights. Hence, the less the fertilizer,the less the runner growth, and the more the uprights will form. Too much fertilizer, and you will reduce the number of uprights that are formed. The best way to see how much fertilizer you need is to test the soil every other year by contacting your Extension Office and getting a soil testing
kit. These tests can give you a better indication of how much fertilizer to add so that you do not over fertilize. Use your test
results and compare them to the commercial grower information found in Washington, Oregon, Wiscosin, New Jersey or Massachusetts.
Harvesting ![]() By the end of the first year, you will want to pick off and eat any berries that formed. Harvest them by hand before the first frost. Typically in New England that is around late September to Early October. You can tell when the berries are ready by the brown color of the seeds when you open a berry. If the plants and berries got alot of sun, the berries will be the typical burgundy color of fall. It is a myth that you should pick the berries after a frost. Cranberries cannot stand a frost below 30°F so it is best to pick them before a hard frost. If you want to wait to get more color in the fruit, then make sure you cover the bed with plastic or a blanket during the frost nights. Many people ask how many cranberries one can expect from a planting. Well, my rule of thumb is that, once the bed has filled in
with runners and uprights, you should be able to harvest one (1) lb of fruit for every 5 sqft of bed. NOW, that assumes that
you have about 100 uprights in a square foot of bed area. The way I count the uprights is to take a one square foot square and
place it on the bed and count the uprights in the square. If you have too few uprights, you will need to work to fill in the bed
more with runners by more fertilizer, OR, if you have too many runners, cut back on the fertilizer to balance the growth.
Protecting Your Plants for the Winter ![]() Cranberry leaves are evergreen and they will dry out if the ground freezes and the leaves cannot get moisture. Be sure to protect your plants in during the winter season. You can achieve this by mulching the plants with pine needles or leaves in late November just as the ground freezes(this will protect against the drying effect that winter brings). Another method is to use polyspun row covers or opaque plastic first, then add the mulch. DO NOT use clear or black plastic, as those plastics will heat up the bed in the winter and kill your plants. You will probably want to mousebait under the plastic or leaves to keep rodents from nesting and damaging your plants. They like to chew on the stems during the winter.
To make a simple mouse bait house,take a roof shngle, bend it to a tent, and place a mousebait station under it. Perhaps put two under the plastic. Uncover the plants on April 1st but continue to protect the plants against frost by covering them back up during
frosty nights, mainly after the shoots start to grow in early May. New shoots can stand about 28F but below that they may get
killed, which would eliminate your fruit for that year.
. Other Practices to Keep Your Planting Healthy
![]() Cranberries are self pollinating; two varieties are not needed. Bumble bees and honeybees benefit pollination. Anything you can do in your garden to encourage bumblebees will help you produce more cranberries.
Pest Control We recommend that you do not use any form of pesticides in your garden bed. Now, having said that, if you do get a leaf or fruit disease there are organic and nonorganic sprays you can use for various insects and leaf diseases. We will mention a few here. Cranberry Tipworm = Cranberry tipworm is relatively new to cranberry country. These buggers can eat the young tip of the upright in the spring and summer, and prevent the upright from fruiting the following year. There are expensive chemicals you can purchase, but I suggest that, if you get this insect, you use a number of yellow soapy traps to catch the buggers when they first take to flight in late May. place the pan with water and soap out next to the cranberry plants. The pan needs to be yellow for this to work. Usually you can put them out in May, and keep emptying and refilling the trap with new soapy solution every two weeks. Cranberry Fruitworm = If you get too many berries that have berry fruitworm, you can use a trick I use and look for red berries in August. If the berry is red in August, that means it has been infested with a worm. Pick off those berries and the few around that berry, as the worm may have moved to another fruit by that point. Dispose of those berries. Red Spot and Berry Fruit Rot = These two diseases are easy to control with an organic copper spray. If you find leaf spot or if alot of your fruit rots before harvest, you can spray copper weekly from late june to early August. Follow the directions on the label to determine what the amount and timing should be. If you have any further problems or would like to know more about cranberry pests, you may purchase the Maine Cranberry Grower's
Guide at your local Cooperative Extension Office. Or you may contact the Massachusetts IPM Notebook: Cranberry Experiment Station
P.O. Box 569, East Wareham, MA 02538 (617) 295-2212 There are many sources of information on cranberry pest control on the web these days.
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