I have a fun one. In the backmatter of Culpeper's Complete Herbal, there's one section called "Of gathering, drying, and keeping simples, and their juices," and in it, Culpeper has this fun thing to argue about roots and sap:

Give me leave to be a little critical against the vulgar received opinion, which is, That the sap falls down into the roots in the Autumn, and rises again in the Spring, as men go to bed at night, and rise in the morning; and this idle talk of untruth is so grounded in the heads, not only of the vulgar, but also of the learned, that a man cannot drive it out by reason. I pray let such sapmongers answer me this argument; If the sap falls into the roots in the fall of the leaf, and lies there all the Winter, then must the root grow only in the Winter. But the root grows not at all in the Winter, as experience teaches, but only in the Summer: Therefore, If you set an apple-kernel in the Spring, you shall find the root to grow to a pretty bigness in the Summer, and be not a whit bigger next Spring. What doth the sap do in the root all that while? Pick straws? ’Tis as rotten as a rotten post.

So, here's my botany question. My understanding is that, in fact, the "sapmongers" were sort of correct--in the fall and winter, sugars go back down to the roots; whereas water continues to be sucked up into the tree until it reaches a winter threshold. In the spring, the sugars shoot back up, hence the explosion of sap. Is this correct? Thanks! lex

Rich said: Hi Lex You and those vulgar sapmongers are correct - this is very much what happens. That is exactly why sugar maples are tapped in the late winter / early spring (warm days, cold nights) when the sap is rising; so Culpeper would have picked a fight with Native American maple syrup makers who knew that for millennia... Not the first time I suppose that an elite-minded "expert" proved to be wrong and those pesky common folk to be correct! And, far from the only thing ol' Nick Culpeper got a bit wrong, like when he cites a French physician, without refuting or even really questioning it, who asserts that eating basil can cause a scorpion to grow in your brain. Unless he was onto something we have yet to discover about basil with a carefully designed study. Culpeper is fun to read, but speaking of long-dead English herbalists, I much prefer Gerard. Check him out if you haven't already. So - from what we know, root growth and activity continues at least when the soil temp is above freezing, even if more slowly in some cases than in warmer months. In the UK I am not sure how often the soil goes below freezing, with the soil being warmer of course than the air especially as you get down to the level of most tree roots; it is certainly milder than Northeastern N. America. Here is a link to one article that is mainly about the impact of climate change on plants, but discusses the winter activity of trees. Here is a quote from it: Much of this winter activity occurs in soil, where an insulating layer of snow can keep temperatures warm enough to support a wide range of biotic activities, such as root growth and microbial respiration. And here is a paper about winter root growth of bulbs. Thanks for the question! Rich the vulgar sapmonger

Rich, Thanks for this. I have been reading Culpeper for my day job of book editor, and he is the first I've read of the ye olde English herbalists. I can't remember where—maybe in Graeme Tobyn—that Culpeper basically took all of the herb parts of his Complete Herbal from either Gerard or was it Parkinson? One of them. Then he added his embellishments of astrology and some lovely tidbits like the one you mention. I wonder if his translation of the London Pharmacopeia was filled with all of these weird remedies. Like grasshoppers being good for colic and crabs' eyes for constipation, or the brains of sparrows to provoke lust. (As you can see, I'm in the living creatures part of the family dispensatory. One of my very favorite things about Culpeper is that half the time, instead of a description of the plant, he will say, "This plant needs no description because everyone knows it," and as someone who was trying to ID these plants and attach to them scientific names—I can say that YES WE NEED THE DESCRIPTION. Thank you for the links. I will read them! Lex, the sap detective