Many fruit trees and plants with colorful flowers (roses and daffodils) have larger pollen grains that don't blow around. You don’t need to worry about them.

Tiny pollen you can’t see causes sneezing and itchy, runny noses.

Pollen isn’t the only problem, though. Some people are allergic to molds from composts and bark mulch as it breaks down. Buy finished compost if you have a mold allergy.

This pesky weed, which grows across the U.S., bothers 75% of Americans with pollen allergies.

If you have a ragweed allergy, watch what you eat and drink. Bananas, cucumbers, zucchini, melons, and sunflower seeds can cause you to itch and swell around your mouth, especially during ragweed season. Your body confuses the proteins in these foods with the proteins in ragweed.

Showering or bathing before bedtime washes off pollen that might be in your hair and on your skin and keeps it off your pillow and bed.

If you’ve been outside when the pollen count is high, change your clothes near your washing machine if you can, so you don't bring the pollen throughout the house, and put them in the laundry before bathing.

Keep windows and doors shut and use an air conditioner with a HEPA filter.

Trees put out pollen in the late winter and spring, and grasses release their pollen in the late spring and summer.

Weeds cause hay fever -- the common name for seasonal allergies -- in the late summer and fall.

Some people are allergic to pollen of cedar trees, which peaks in late winter as well as spring. Warmer winters cause trouble for people with spring allergies: Their symptoms start earlier.

Pollen levels are usually highest between 5 a.m. and 10 a.m. Wait until the afternoon to go outside if you can.

Pollen travels best on warm, dry, and breezy days. Rain washes away pollen, and counts are usually lowest during or just after rain.

Don’t expect to feel better right after getting your first allergy shot. Everybody reacts differently, but it usually takes four to six months of shots -- once or twice weekly at first, then less often -- before you feel any relief.

For most people, their symptoms get better after the first year of shots.

Allergy shots contain a small amount of the thing you are allergic to, so your body can slowly get used to it and not have allergic reactions anymore.

Using an over-the-counter decongestant nasal spray for more than three days at a time could make you more congested. When the effects of the spray wear off, the tissue inside your nose and sinuses could swell more. You might then use more spray -- making the swelling worse.

Consider using a prescription nose spray, which reduces swelling. If you are congested often, see your doctor about a prescription steroid spray.

Louisville tops the list as the worst big city in the U.S. for fall allergies. The city that's home to the Kentucky Derby got the No. 1 spot in 2012 based on high pollen counts, residents’ use of allergy medications, and the number of allergy doctors in the area, the Asthma and Allergy Foundation of America said. Sacramento, Calif., was the best place for people with fall allergies.

If allergies are making your eyes watery or itchy, consider wearing a hat with a wide brim when you are outside. It will help keep pollen from blowing into your eyes.

Wearing sunglasses also helps, and using saline drops after being outdoors washes away pollen from the lining of your eyes.

Taking a vacation might clear up your symptoms for a while, but moving won’t make your allergies go away. Some plants and grasses grow all over the U.S., making them tough to escape. And, within a few years, you are likely to develop allergies to plants and grasses near your new home.