Guides

Plain-English writing on allergy season — what's in the air, how to read a pollen forecast, what to take, and when to actually see a doctor. New pieces published through the season.

The basics

• When does allergy season start?
  Tree, grass, ragweed, and mold — when each one begins, when it peaks, and when it ends. Plus why "allergy season" is really four overlapping relays, not one continuous stretch.
• Pollen count explained — what the numbers actually mean
  A reading of "high" means different things for trees, grass, and weeds. Here are the real thresholds (grains per cubic meter) and how to interpret a forecast in your daily routine.
• The year-round allergy calendar
  Month by month: what's pollinating, when, where. Useful for planning outdoor events, travel, and prescription refills.

Symptoms

• Is it allergies or a cold?
  Runny nose, sneezing, congestion — the overlap is real. Here's how to tell them apart quickly: the one symptom that almost always means allergies, why discharge color matters, and how the pollen count changes the math entirely.
• Is it allergies or the flu?
  Spring is both peak allergy season and still flu season. Here's how to tell them apart — and why flu has a 48-hour treatment window that makes getting this wrong genuinely costly.

Pollen by type

• Tree pollen: oak, birch, maple, and friends
  Which trees cause the most trouble, how to tell which is getting you, and why oak pollen seems to coat everything yellow for three weeks every April.
• Grass pollen: the May–July grind
  Once tree season ends, grass picks up the baton. Worst offenders by region, why mowed lawns still release pollen, and why symptoms often get worse on breezy afternoons.
• Ragweed: the late-summer finale
  August through first frost. Why ragweed ruins the last good weather of the year for about 20% of Americans, and what (if anything) actually works against it.

Cross-reactivity & food

• Oak & birch pollen: why raw apples and stone fruits make your mouth itch
  If raw apples, peaches, or cherries tingle during spring allergy season, you have oral allergy syndrome. Here's the protein biology, which foods are affected, and what actually helps.
• Grass pollen cross-reactivity: tomatoes, potatoes, melons, and OAS in summer
  Grass pollen allergy can trigger oral reactions to tomatoes, potatoes, kiwi, and melon. Here's the profilin biology, the foods to watch, and what to do about it.
• Ragweed cross-reactivity: melons, bananas, and oral symptoms in fall
  Ragweed and mugwort pollen allergy can cause oral reactions to watermelon, cantaloupe, banana, cucumber, and zucchini. Here's what's happening and how to manage it.

Treatment and relief

• When to start allergy medication — and why timing matters
  Nasal sprays don't work the day you take them. Here's how to get ahead of the pollen peak, what to do if you've already missed the window, and why symptoms lag the count even after it falls.
• Antihistamines compared: Claritin vs Zyrtec vs Allegra vs Flonase
  The differences between the big over-the-counter options — how fast they work, how drowsy they make you, how to pick the right one. Plus why Flonase plays a different role entirely.
• Do HEPA filters actually help?
  Short answer: yes, in one specific scenario. Longer answer covers what a HEPA actually does, where in the house it belongs, and why the room-sized ones with the giant fan blades aren't a gimmick.
• When to see an allergist (and what to expect)
  If OTC medication isn't working, if symptoms are worsening year over year, or if you want to know specifically what you're allergic to — here's what an allergist visit looks like from start to finish.

The bigger picture

• How climate change is extending allergy season
  Pollen seasons are starting earlier and lasting longer than they did thirty years ago — a measurable, published consequence of warming. Here's what the research says, in plain terms.

State guides

When pollen season starts and ends where you live, which species dominate, and how the state's regions differ.