Commentary

HOW BEES AND FLOWERS COMMUNICATE

Study Shows That Bees and Flowers Communicate Using Electrical Fields

February 22, 2013 by Staff

Biology

Bees and Flowers Communicate Using Electrical Fields

Various flowers (Left: Geranium magnificum; Middle: Gerbera hybrida; Right: Clematis armandii) showing a composite of immediately before and after application of charged powder paint. The pattern of powder deposition reveals the shape of the electric field. Image by Dominic Clarke and Daniel Robert

Scientists from the University of Bristol have discovered that flowers use patterns of electrical signals in concert with the flower’s other attractive signals to enhance floral attraction to insect pollinators such as bumblebees.

Flowers’ methods of communicating are at least as sophisticated as any devised by an advertising agency, according to a new study, published today in Science Express by researchers from the University of Bristol. However, for any advert to be successful, it has to reach, and be perceived by, its target audience. The research shows for the first time that pollinators such as bumblebees are able to find and distinguish electric signals given out by flowers.

Flowers often produce bright colors, patterns and enticing fragrances to attract their pollinators. Researchers at Bristol’s School of Biological Sciences, led by Professor Daniel Robert, found that flowers also have their equivalent of a neon sign – patterns of electrical signals that can communicate information to the insect pollinator. These electrical signals can work in concert with the flower’s other attractive signals and enhance floral advertising power.

Plants are usually charged negatively and emit weak electric fields. On their side, bees acquire a positive charge as they fly through the air. No spark is produced as a charged bee approaches a charged flower, but a small electric force builds up that can potentially convey information.

By placing electrodes in the stems of petunias, the researchers showed that when a bee lands, the flower’s potential changes and remains so for several minutes. Could this be a way by which flowers tell bees another bee has recently been visiting? To their surprise, the researchers discovered that bumblebees can detect and distinguish between different floral electric fields.

Also, the researchers found that when bees were given a learning test, they were faster at learning the difference between two colors when electric signals were also available.

How then do bees detect electric fields? This is not yet known, although the researchers speculate that hairy bumblebees bristle up under the electrostatic force, just like one’s hair in front of an old television screen.

The discovery of such electric detection has opened up a whole new understanding of insect perception and flower communication.

Dr Heather Whitney, a co-author of the study said: “This novel communication channel reveals how flowers can potentially inform their pollinators about the honest status of their precious nectar and pollen reserves.”

Professor Robert said: “The last thing a flower wants is to attract a bee and then fail to provide nectar: a lesson in honest advertising since bees are good learners and would soon lose interest in such an unrewarding flower.

“The co-evolution between flowers and bees has a long and beneficial history, so perhaps it’s not entirely surprising that we are still discovering today how remarkably sophisticated their communication is.”

The research was supported by the Leverhulme Trust.

Publication: Dominic Clarke, Heather Whitney, Gregory Sutton and Daniel Robert, “Detection and Learning of Floral Electric Fields by Bumblebees,” Science DOI: 10.1126/science.1230883

Source: University of Bristol

Image: Dominic Clarke and Daniel Robert

John Scheepers Kitchen Garden Seeds

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The Essential Seed-Starting Timetable
Thank you for having signed up for horticultural emails from Kitchen Garden Seeds, Van Engelen and John Scheepers*. Pictured from top to bottom: Quadrato d'Asti Bell Peppers, Milano Plum Tomatoes, Magenta Sunset Swiss Chard and Heavenly Blue Morning Glories.
As winter settles in across the country, now is the perfect time to snuggle up with our Kitchen Garden Seeds catalog to plan your garden. Make a wish list of the vegetables, herbs and flowers that you would like to grow. Think about what you want to harvest for delicious homegrown and homemade dinners with family and friends, and bracing feasts to put up or freeze for hearty nourishment on cold winter nights like these. Don't forget about flower seeds to fill your gardens with opulent summer and fall flowers~it is so much less expensive than buying individual plants later in the spring. By growing your own from seed, you can select from among the best varieties under the sun. There are few things more rewarding in life. It is contagious goodness borne of one's passion and the magic of seeds. Never underestimate the power of planting.
Part One: Seeds to Start Indoors
Did you ever wonder why certain varieties of seed are started indoors? It is usually because the days to mature harvest exceed the amount of time between your spring Frost-Free Date and your first fall frost. By starting these varieties indoors in advance, you get a four to 14 week jump-start on the development of seedlings. Other varieties like to be started indoors so that you can really pamper them with consistent moisture and warmer temperatures. Real warmth-lovers, like Eggplants, Peppers and Tomatoes, like to be coddled with 24-7 grow lights until they are 'toddler' seedlings when they can start to handle cooler, dark nights.
It's best to consider your seed order in two parts. The first should include the varieties that you must start indoors for transplant into the garden after your Frost-Free Date. You can find your reliable Frost-Free Date by using a nifty chart from the National Oceanic and Atmospheric Administration (NOAA). GO HERE and select your State from the pull down menu. This will generate a PDF file with a list of NOAA data collection sites in your State. In the left column, choose the location nearest or most similar to where you live. Then read across. Use the middle threshold number (32F) and right next to it in the Spring column, will be the 90% probability date. This is your all-important Frost-Free Date.
Eight-week General Seed-Starting Timetable
Here is the general Seed-Starting Schedule for seeds that should be started eight weeks before your Frost-Free Date in your Horticultural Zone.
Horticultural Zones 9 & 10:  Start seeds indoors in early to mid January.
Horticultural Zone 8:  Start seeds indoors in early February.
Horticultural Zone 7:  Start seeds indoors in mid February.
Horticultural Zone 6: Start seeds indoors in late February.
Horticultural Zone 5: Start seeds indoors in early March.
Horticultural Zones 1-4: Start seeds indoors in mid to late March. 
Vegetable and Herb Seed-Starting Timetable
Here is the seed-starting schedule by variety and the number of weeks before your Frost-Free Date.  
Four Weeks: Bitter Melon and Cucuzzi Edible Gourds.
Six Weeks: Asparagus, Basil, Echinacea Root, Fennel (herb and vegetable), Melons, Okra, Onions, Rhubarb and Shallots
Eight Weeks: Amaranth, Anise Hyssop, Bell Peppers, Catnip, Chile Peppers, Chives, Lovage, Marjoram, Oregano, Paprika Peppers, Parsley, Sage, Savory, Sweet Peppers, St. John's Wort, Thyme, Tomatillos and Tomatoes.
Nine Weeks: Broccoli, Cabbage and Kohlrabi (transplant out four weeks before the last frost date).
Ten Weeks: Eggplant, Jicama, Lavender and Lemongrass.
Eleven Weeks: Artichokes, Cauliflower and Leeks (transplant out four weeks before the last frost date).
Twelve Weeks: Brussels Sprouts, Cardoons, Celeriac, Celery, Cutting Celery, Parsley Root and Stevia.
Sixteen Weeks: Rosemary and Strawberries (for first year crop).
Flower Seed-Starting Timetable
These beautiful varieties prefer to be started indoors prior to transplanting out after your Frost-Free Date.
Two Weeks: Baptisia.
Four Weeks: Celosia.
Five Weeks: Alyssum.
Six Weeks: Dahlias and Echinacea.
Eight Weeks: Alternanthera, Amaranth, Baby's Breath, Balsam, Black-eyed Susans, Cutting Ageratum, Canterbury Bells, Catmint Nepeta, China Asters, Cleome, Coleus, Coreopsis, Euphorbia, Forget-Me-Nots, Gaillardia, Globe Amaranth, Hardshell Gourds, Helichrysum Strawflower, Heuchera, Milkweed, Nicotiana, Nigella, Platycodon, Scabiosa, Snapdragons, Statice, Stock, Thunbergia, Tithonia and Yarrow.
Ten Weeks: Hibiscus, Phlox and Victoria Salvia.
Twelve Weeks: Datura, Dianthus, Digitalis, Helichrysum Silver Mist, Heliotrope, Hollyhocks, Johnny Jumpups, Lobelia, Salvia and Viola.
Fourteen Weeks: Verbena.
Midsummer for Fall Use: Ornamental Kale.
Part Two: Seeds to Direct-Sow Easily Outside
The second part of your order should include varieties that prefer to be direct-sown easily into the garden after your Frost-Free Date. These are the vegetables and herbs that magically come to life after you gently nudge them into the warming spring soil for abundant reward: Arugula, Asian Greens, Beans, Beets, Belgian Endive, Borage, Broccoli Raab, Brown Mustard Seed, Carrots, Chamomile, Swiss Chard, Chervil, Chicories, Chinese Broccoli, Chinese Cabbage, Claytonia, Collard Greens, Coriander, Corn, Cress, Cucumbers, Daikon Radishes, Dandelion Greens, Dill, Edamame, Endive, Escarole, Fava Beans, Fennel, Kale, Kohlrabi, Lemon Balm, Lettuce, Lima Beans, Mache, Melons, Minutina, Mizuna, Mustard Greens, Orach, Pak choi, Parsnips, Peas, Pea Pods, Pumpkins, Radicchio, Radishes, Rutabagas, Salad Greens, Salsify, Shelling Beans, Shiso, Snap Peas, Sorrel, Spearmint, Spinach, Summer Squash, Winter Squash, Turnip Greens and Turnips.
We share our best-of-the-best recipes so you can feed your family and friends well without feeling frenzied. Take a look at our practical, hands-on horticultural tips to demystify gardening with seeds (it need not be tricky or difficult. Truth be told, it is a bit more like easy magic.) If you need help with anything, our office hours are Monday through Friday from 9:00 a.m. to 5:00 p.m. Email us at This email address is being protected from spambots. You need JavaScript enabled to view it. or call us at (860) 567-6086. We can help you make your garden more easily tended and productive which in turn will help to keep gardening a happy, essential part of your family's life. Lance Frazon, our seed specialist, is happy to help you in any way possible. He loves to talk seeds.
-To see our seed collection click: Flowers, gourmet fruits & vegetables and aromatic herbs.
-To request a 2013 Kitchen Garden Seeds catalog, click: Request catalog.
-To look at our yummy recipes, like Crab and Shrimp Gratin, click: Recipes.
-Or, call us at (860) 567-6086: we will help you in any way we can!

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WHAT TO DO WITH MY CHRISTMAS CACTUS

Although the poinsettia is the plant most
closely associated with the holiday season, the
Christmas cactus is a great plant that is becoming
more widely given and enjoyed. The Christmas
cactus (Schlumbergera x buckleyi) is not a true
cactus and does not have the prickles that the
name implies. A native of the humid, shaded rain
forests in Central and South America, the Christmas
cactus is an “epiphytic,” a plant that grows
on other plants but is not parasitic. The Christmas
cactus is leafless with flattened, scalloped,
smooth green stems on spineless joints. The tubular,
rose-like flowers have many petals and extend
from the end of the stem segments.
Christmas cactus is unique and versatile
and is sold in a range of sizes from 3-inch pots to
hanging baskets. And Christmas cactus plants
have the virtue of continuing to grow and bloom
in the home for many years after the holidays
are over. “We had one that finally died after 23
years,” said Mark Cobia, a grower in Winter Garden,
Florida. “It is not uncommon for them to
live 10-14 years, though the average life is probably
five years.” Christmas cactus plants come in
more than 65 varieties with a range of colors from
whites and yellows to reds and purples.
Most problems in maintaining the Christmas
cactus seem to come from over- or underwatering.
Because of the name, many assume
that Christmas cactus can survive without any
water. That assumption is not true. To keep your
plant growing well, water thoroughly when the
top half of the soil in the pot feels dry to the touch.
Stick your finger down in the dirt to get a good
reading on the moisture level. After the soil has
absorbed as much water as it can, discard any
remaining water in the saucer. Standing water
will cause problems. Do not water again until the
top half becomes dry again.
The soil in your plant should be well-draining.
Don’t repot your plant until it is obviously
crowded and repot only while it is young and actively
growing. Very old plants resent being disturbed.
If you need to transplant your Christmas
cactus, select a potting mix for succulent plants
(with a little compost thrown in).
To maintain the lovely blooms that arrive
with your plant, keep it in a well-lighted location
away from drafts from heat vents, fireplaces or
other sources of hot air. The blooms will last longer
if they are kept in a cooler spot.
While Christmas cactus can adapt to low
light situations, they will perform better in bright
light. More abundant blooms are produced on
plants that have been exposed to high light intensity.
If you keep your plants in a sunny location
indoors, they will reward you with more blossoms.
Light, however, should be indirect. Direct
sunlight can burn the leaves. If you move your
plant outdoors in the summer, keep it in a spot
that receives filtered light or bright shade. When
it’s time to bring the plants back inside in the fall,
slowly adjust the plant to life indoors by gradually
increasing the number of hours they spend
indoors each day.
Once your Christmas cactus has finished
its initial bloom, you should encourage branching
by carefully pruning the plant. Remove a few
sections of each stem by pinching them off with
your fingers or cutting with a sharp knife. These
sections can be rooted in moist vermiculite to
propagate new plants.
Like poinsettias, Christmas cactus need
some nudging to bloom at Christmas time. Sensitive
to the length of day, you should induce
blooming by controlling the amount of light the
plant gets. Begin the dark treatments in about
early to mid-October to have plants in full bloom
by the holidays. They need to be placed in uninterrupted
darkness for at least 14 hours a day
at a temperature of around 60°-65° F. Christmas
cactus will also bloom if they are subjected to
cool temperatures of about 50° to 55° F. at night.
Plants will be ready for the holidays if the cool
treatments are started by early November. Once
buds begin to form at the end of the leaves,
move your plant into brighter light and feed with
a weak fertilizer high in potash every two weeks
or so. Keep feeding until early summer, then stop.