This list of poison ivy preventatives and remedies is specific to the New England area.

Poison Ivy Season

May - October: The poison ivy season typically begins in early May. It tends to go from zero to one-hundred in about a week; once the first shoots begin to appear, it's time to be concerned. The season ends in late October, depending on the climate.
Year Round: Technically you can get poison ivy at any time of the year. Even when the plant is not in season ivy vines and roots are still active.

What Poison Ivy Looks Like

Poison ivy is a bit tricky because it looks like a lot of other plants. Here are some ways to distinguish it – in New England:

“Leaves of three; let it be.” Three leaves per grouping – on each stem. Typically the orientation of the leaves is like a playing card club – leaves are about 90 degrees to each other.
Leaves are shiny with oil. Later season it tends to dry out.
It’s very low to the ground. Never more than a foot high – usually around 10″ tall. It can grow up to 4 feet high but it's rare to see this in the Boston area.
Leaf edges are smooth – no edge serrations or designs.
Poison ivy's color and sheen changes throughout the season:
- Early Season - May: Leaves are red and then turn to a pale green. They can either be dry in appearance or very shiny.
- Full Season: Very bright deep green. Smaller leaves are lighter green; bigger leaves are deeper green.
- Late Season: September - October: Leaves are reddish and tend to be drier in appearance - not shiny.

Where Poison Ivy Lives

Wooded areas - wherever you're riding.
It tends to grow around edges of shaded areas – not too shaded. This often means the edges of trails – on which you’re riding. It rarely thrives in direct sunlight.
It tends not to grow in grass; it doesn’t like competition. It will usually be the only plant in it's spot; but it can be right next to other plants that look kind of similar.

How To Avoid Poison Ivy:

Know what it looks like.
Wear long socks.
Try this: Invisible Glove. We’ve never used this.
Don’t ride in poison ivy areas during the season.
Don’t crash into it.
Don't ride through it; if you have to change a flat after riding through poison ivy, you will regret it.
Carry latex gloves in your repair kit in case you have to do mechanical work on your bike - particularly your tires.

What To Do If You Frolic In Poison Ivy

You want to wash up as soon as possible; within minutes is best. However, we've continued rides for a few hours after rolling in ivy, cleaned up when we got home, and not contracted it - even though some of us at Overland Base Camp are very allergic. There are two discret steps to washing up:
- Step One: Scrub with cold water - and no soap, yet. Cold water is better than hot because cold water closes pores; hot water opens pores. Closed pores make it difficult for the urushiol to get into your system.
- Step Two: Wash with soap. The issue is that soap breaks up the urushiol and makes it easier to absorb through your skin, so you want to remove as much of the oil as possible with cold water before applying soap.
We've found Cat's Tongue cleaning towels to work really well. It appears to remove the oil without breaking it up. It's a great on-ride trail fix if you end up in poison ivy.
Rubbing alcohol works marginally better than soap and water.
Tecnu works marginally better than soap. We have not had good success with this.
Jewel Weed. The fluid in the stalk of jewel weed helps prevent poison ivy. If you ride through ivy, you can apply jewel weed salve to the area and help prevent the spread of poison ivy. It typically grows in the vicinity of poison ivy. Yellow flowers. Here's a video that shows how to apply jewel weed. Thanks to Matt Roy for telling us about this!
Shoes, gloves, clothing, and bikes that come in contact with the plan need to be washed. Poison ivy oil can be active for a couple years. Unfortunately, washing leather and suede doesn’t always remove all the oil. Some people recommend Fels-Naptha as a home remedy for washing leather and suede.

What to do if you get poison ivy:

Symptoms appear within 3-7 days. And last about 1-3 weeks. Yay.
Hot water – as hot as you can stand it – helps reduce itching immediately and for a few hours; hot water helps draw out histamines that make the area itch. Our suggestion: pour hot water on a face cloth and apply to the rash; it feels so good and eliminates itching for a while.
Ice water or ice cubes applied locally can reduce itching for a short time.
Anti-itch drugs can potentially help. Benadryl or Lanacane are two examples.
Calamine Lotion: The FDA has asserts that it has little, if any, effect. We've found the same to be true.
It's not contagious: Once you’ve got it you cannot pass it on to others. Even if you have lesions that leak, the liquid does not contain urushiol.

Why Avoid Poison Ivy

Poison ivy oil stays on clothes, tires, pedals, brake levers, and anything it touches. Even months later you can still get a rash if you touch those items that have been contaminated. The oil can remain active for a couple years. Even washing clothing does not typically remove all poison ivy oil.
The more often you get it, the worse you tend to get it. It is an allergic reaction.
Most people are allergic to it, about 85% of the population. It’s super unfun to get it. Very itchy in a bad way and it lasts for a couple-three weeks.
The poison ivy rash can cause long-term scarring.
The rash has a rather unpleasant appearance.
It's really itchy. The more you scratch, the more it itches.

Random notes:

I heard from Matt Roy that one of the reasons that poison ivy is so prevalent in the Boston area is that it was actually a crop raised by farmers. Why would someone raise poison ivy? Apparently its very high in vitamin C, cows are not allergic to it. Farmers used poison ivy to feed cows.

Sources: