Sally Scalera

Brevard County Horticulture Extension Agent
3695 Lake Drive -- Cocoa FL 32926 -- 321-633-1702

Bees important to gardening

May 13, 2006

Just last week we had a request for an old article of mine that was on bees and how to make a bee house. Then, this weekend, I was out working in my yard and I realized that there were butterflies flitting everywhere and bees buzzing all around. That was when it occurred to me that bees are an important part of the garden and a good topic for another article.

Did you know that about 90 food crops are pollinated by insects, mostly bees? Thanks to bees we have apples, citrus, avocado, mango, plums, peaches, pumpkins, squash, strawberries, raspberries, cranberries, carrots, cabbage, broccoli, onions and watermelon. Some of these plants need bees to pollinate them so seeds will be produced for planting the next year. If you add in the crops that are used to feed livestock, that would mean that one third of our food supply is dependent upon flowers pollinated by bees.

Now, I’m not talking about honeybees which live in large hives and can become aggressive when protecting it. No, I’m talking about native bees which are also called pollen bees or solitary bees. There are more than 3500 species of solitary bees in North America. These bees are efficient pollinators and often do the majority of the pollinating of our crops.

Pollen bees have a number of advantages over honeybees as pollinators. For example, they fly rapidly and can pollinate more plants; they are usually gentle and don’t sting; they can work on cloudy days and start earlier in the morning (like 7 a.m. or earlier) and work later in the afternoon then honeybees. Bumble bees, digger bees and sweat bees make up the bulk of pollen bees in most parts of the county. In order to encourage pollen bees we must provide nesting habitats, stop using harmful pesticides and provide suitable plants.

Here are some good ways to increase native bee populations. Start by setting aside some undisturbed areas around our yards. Most bees prefer to nest in dry places and love a sunny location. For ground nesting bees, this means a patch of undisturbed soil in a sunny spot. For wood or stem-nesting bees, this means piles of bamboo sections, branches, hollow reeds or nesting blocks made out of untreated wood.

The second step is to reduce the use of harmful pesticides. The extensive use of pesticides not only on farmlands but also in our landscapes has contributed to the loss of many bees and other pollinators. Even natural herbicides and botanical insecticides can harm bees. To protect bees all pesticides should be applied in the evening when bees are in their nest. The third way is to furnish the pollinators with food by planting the right nectar rich plants for them. Some good bee plants are asters, bee balm, calendula, coneflower, daisies, impatiens, milkweed, mints, nasturtiums, red clover, coreopsis, verbena, salvias and sweet lavender.

Native bees can be mainly divided between soil and wood dwellers. Soil dwelling bees include bumble, digger, sweat, and squash bees. Bumble bees are hard workers that work faster then honeybees and can be out in cooler temperatures. Bumble bees pollinate many of our most common vegetables like tomatoes, eggplants, peppers, melons, blackberries, strawberries and blueberries. quash bees only visit flowers of squash, pumpkin and gourds. They are early risers too and will visit all of the squash flowers by midday when the flowers close up. All of these bees that live underground prefer south-facing, dry, sandy banks that are clear of vegetation.

Wood dwellers include our leafcutters and carpenter bees. The leafcutter bees are partial to legume blooms but will pollinate other crops like carrots. They are most active when the temperatures are above 70 degrees. They are also very efficient pollinators so it takes a lot fewer leafcutter bees then honeybees to pollinate the flowers. Carpenter bees are some of the biggest bees and prefer to create holes in softwoods like pine but will avoid wood that is painted or covered in bark, normally. The entrance to their nest will be a ½” diameter hole. Carpenter bees pollinate several crops like passion fruit, blackberry, corn, pepper and pole beans.

An inexpensive artificial nest, for leafcutter bees, can be created out of plastic or paper straws (approximately ¼ “ to 3/8” in diameter) packed into a coffee can, milk carton or PVC pipe and then all glued together. These artificial nests can then be attached to tree trunks, fence posts, or the side of a building or shed. Make sure they are three to six feet off the ground. Place the nests so that the holes are horizontal and the bees at least receive the morning sun. Also be sure to protect the nests from the elements like rain, snow and wind and from predators like woodpeckers and mice. Other ways to create nests include drilling holes in dead trees and creating bundles of pithy-stemmed plants like bamboo, goldenrod and sumac.