When should I revisit my porcini patch?

October 26, 2009 3:20 PM

How quickly do porcini grow?

The first fall rains came to Marin county (north of San Francisco) slightly less than two weeks ago, which means bolete season is about to begin - folk wisdom in this area is two to four weeks after the first fall rains. I got into foraging for mushrooms about a year ago, at the tail of last year's season, and by the time I was out and about most of the boletes were already blown (too old to eat, maggoty, etc).

Yesterday on a recon hike I found a clump of very young boletes in an area with mixed pines and oak and medium/high humidity. Each mushroom was no larger than my thumb, so I resisted picking.

The question is: when should I go back?

I do imagine the answer depends at least slightly on the weather, as more rain should mean faster growth. I've heard tell of porcini sprouting and growing to full size within a day during a heavy rain, but I haven't heard anything about how quickly they grow under our current conditions: when the ground contains enough moisture to feel loamy and not crunchy, but there's no rain in the near future.

I know I'll be going back this weekend for sure, but I'm considering taking a day off of work in the middle of the week, as I'm afraid my patch may fall prey to other boletivores. Now that the season is on, I have the bug. :)

posted by quasistoic to science & nature (6 comments total)

My experience has been that if it's going to grow to full size, it'll do it in 1-2 days usually, and 3 days on the outside. So I think you should take a day off. Get those porcinis!
posted by emyd at 3:40 PM on October 26, 2009

Never go past a young healthy porcini mushroom, no matter how tiny. Do you want to let the flies find it first?

Answer: revisit now.
Otherwise: emyd nails it - a bit depending on the weather, of course.
posted by Namlit at 4:02 PM on October 26, 2009

Okay, you win. Tomorrow morning I go back.
posted by quasistoic at 7:15 PM on October 26, 2009

Excellent! (The only thing worse than a insect-riddled porcini is a rotting porcini. You can smell it 50 yards away.)
posted by shinybeast at 7:32 PM on October 26, 2009

As a followup:

I went back to the spot where we had found young boletes on Sunday and found them only slightly larger and untouched by bugs or other people. However, I also soon realized that they weren't Boletus edulis, but Suillus caerulescens (Fat Jacks) instead. I've only been at this for about a year, which is how I managed to make this mistake.

While I can't answer my original question yet, I can say that in the two days that passed, the Fat Jacks didn't get much larger than they were initially (the largest I found on Tuesday was probably 3/4 inch thick by 3 inches tall), but a whole lot more of them popped up. I ended up picking about 1.5 lbs of the little guys from the mixed wood of Douglas Fir, California Buckeye, and ferns. They really liked hiding under the ferns, often just a few feet away from where I was pulling chanterelles the last two weeks. For what it's worth, at the same time and not too far away (think the distance of a city block), I also found a good number of Suillus lakei, Gomphideous subroseus, Amanita phalloides (Death Cap), and some older Lactarious rubrilacteus ("Delicious" milk caps) and Lyophyllum decastes (Fried Chicken mushroom).

We're still not getting proper boletes, but looking more closely at where I'm hunting, I think I need to get away from those Douglas Firs and find some real pines.
posted by quasistoic at 8:04 AM on October 29, 2009

As another followup, a friend in the commercial business said "3 days" in response to the same question, and taking into account the current dry weather (and the recent rains).
posted by quasistoic at 10:48 AM on October 30, 2009