How Cranberries Grow: Spring

Removal of Winter Flood

As warmer weather arrives, usually mid-March, growers remove the winter flood. The vines slowly come out of dormancy and the growing season begins.

Late water (Spring flooding)

You may see a bog re-flooded between mid-April and mid-May as a cultural practice to manage insects, weeds and disease.

Frost Protection

Water is applied through the sprinkler system to protect the cranberry bud and tender shoots in the spring. This can occur anytime the temperature drops below damaging levels, usually between late evening and early morning hours. See the Spring Frost page for more photos and video of frost protection.

Weed Management

As in your home garden, weeds in cranberry bogs must be controlled. This is done by an application of herbicides applied by mechanical means, holding late water (spring flooding) or hand pulling.

Ditch cleaning

Ditches are necessary for the flooding and drainage of a bog. The network of ditches must be kept free flowing. Ditch cleaning is usually done in the spring and fall by hand or a mini-excavator. The mud piles are removed by either a bog vehicle or helicopter.


Typically, fertilizers are applied between mid-May and late August. As native wetland plants, cranberry vines require minimal nutrient supplements. When needed, fertilizers are applied in small doses by helicopter, manually, or through the sprinkler system.

Construction and Renovation of Cranberry Bogs

Many of the bogs in Southeastern Massachusetts have been in production for more than 100 years. Sometimes a bog may be replanted because: the bog may not be level, the variety is a low producer or weeds such as briar, poison ivy, or brambles have overtaken the vines. In such cases, large construction equipment is needed to move the soil, leveling the bog in preparation for planting new vines. Growers also may square off beds to increase operation efficiency. From time to time it is also necessary to upgrade or replace irrigation systems and water control structures.