In this episode of "A Rich Spot of Earth" we talk about water: how water was collected and used at Monticello and how to properly water your own plants. We also discuss some of the plants sent back to Jefferson from the Lewis and Clark Expedition, and spend a few minutes on the American Chestnut, the severely endangered native tree that is making a comeback thanks to the efforts of the American Chestnut Foundation (

Featuring Michael Tricomi, Interim Manager and Curator of Historic Gardens; Peggy Cornett, Curator of Plants; Debbie Donley, Flower Gardener; and, Robert Dowell, Senior Nursery Associate at the Center.


Robert Donley: It's July here at Monticello and if you're a gardener in Virginia, you know it's rough out there. The temperature reaches into the 90s almost every day, and it's so humid, 10 minutes outside can leave you drenched.

But flowers like Larkspur, Blanket Flower, and Purple Coneflower are blooming in our flower beds and we’re harvesting tomatoes, beans, and summer squash from the vegetable garden. What keeps our plants happy this time of year? Water. That's going to be our focus this episode.


Michael Tricomi: This is “A Rich Spot of Earth,” a podcast about gardening and the natural world. I’m Michael Tricomi, Interim Manager and Curator of Historic Gardens at Monticello, Thomas Jefferson’s home in Albemarle County, Virginia.


Michael Tricomi: Thomas Jefferson built his home on a mountaintop for the incredible views. But that meant he sacrificed easy access to water. Recently, I sat down to talk about water with our curator of Plants, Peggy Cornett and our flower gardener, Debbie Donley.

Peggy Cornett: Watering or irrigation in Jefferson's Day was challenging, I think. Monticello's water sources were very sparse. The closest major water source was the Rivanna River, which is at the bottom of the mountain, about a mile away. Jefferson's enslaved workers would have to gather water from various sources, including springs that are around the mountain, when they were flowing, which always wasn't the case. The wells would go dry. We believe that there were periods, during drought times, when there were lots of failures in the garden because of the lack of water.

If any watering was done, it was done by the enslaved workforce, and they were hauling barrels of water from the river and from the cisterns. They would have to use buckets to water each plant or run it through a little trough into the garden. It was an enormous amount of work.

Debbie Donley: It's a lot of work with modern hoses, let alone if you had to go collect it at the spring or the river. I can't imagine.

Peggy Cornett: No, it was very difficult. And of course, you're trying not to lose a lot of water while you're transporting it up the mountain, too. That again is another challenge.


Michael Tricomi: Jefferson designed a system for collecting rainwater in underground cisterns. They were constructed from brick and lined with mortar to make them waterproof.

Peggy Cornett: Gutters from the house were channeled into four cisterns that were on each corner of the terraces. They had very ingenious gutters. They were called Philadelphia gutters. So they were inside the roof line, you didn't see gutters hanging out like most people have on their houses. It was buried into the architecture of the house. The water ran down into a series of troughs that ran beneath the terrace boards and funneled into these cisterns. And there was even a well pump that we've restored that's quite ingenious. It would pump the water out of the cistern. But the mortar was not as good as it could have been, so the cisterns would leak. It wasn't as waterproof, as you would like.

He also had an amazing plan to channel water from a spring on Montalto, the big mountain above Monticello, and he wanted to channel spring water in a series of aqueducts down the mountain and then over to Monticello to water the vegetable garden. It would also create a beautiful waterfall coming down Montalto. This was a dream that was never even realized or even begun to realize, but it was a pretty cool idea.

When do plants need to be watered?

Michael Tricomi: An aqueduct stretching from Montalto to Monticello would have been amazing. So how do you know when a plant needs water?

Peggy Cornett: Plants, they usually tell you. I mean, they flag, their leaves droop. You can see it in just newly transplanted seedlings to trees all the way up.

Michael Tricomi: One other way to tell if a plant is too dry, I know that leaf curling we see in the vegetable garden, especially in corn and tomatoes. You'll get that curling of the leaves and that'll be a sign that they're very thirsty. 

Peggy Cornett: I think the leaves are almost trying to reduce the surface area that's transpiring with moisture in it, so they curl up a bit.

Michael Tricomi: July can be one of those months where you could get a good rainstorm and then just a period of long, dry weather.  

Peggy Cornett: High temperatures.

Debbie Donley: You can time your work schedule around the weather and what the plants need. You don't wanna water in the middle of the day, because so much evaporates.

Peggy Cornett: If you have to plant in dry soil, it's good to get it wet ahead of time, and then also make sure the plant you're putting in the ground the roots are hydrated before you plant those tender roots into really dry soil. It's tough on the plant.

Debbie Donley: I have been transplanting a number of cockscomb and balsam, things like that that have self-sown. I have been following my mother's advice. She would always dig a hole and put water in it before the plant went in. I got out of the habit of doing that, but when I was transplanting these poor little shocked cockscombs from one area to another, I would dig the hole, put the water in, and then put the plant in, and then water it again.

Peggy Cornett: Good technique.

Debbie Donley: And then I always make sure I water it yet again the next morning. It also helps if you don't try to transplant too large of a plant. You wanna get that nice big, beautiful one, but they do suffer a lot more because it's more plant that the roots have to sustain. Smaller plants really catch up to what would be bigger plants and they don't struggle as much. It's good practice to go with the smaller ones.

Michael Tricomi: If your plants are drooping water them immediately. But you don't want to water a little bit every day. You want to water thoroughly and then wait a week or so to encourage the roots to reach down into the soil for moisture. That produces good strong roots.

In our greenhouses here at Monticello, we grow a lot of plants from seed. You need to be careful watering seedlings and potted plants.

Peggy Cornett: If you have a potted plant, you can tell by lifting the pot, and if it's very light, it needs water. And you water in trays and then put the flats in there so that they soak up the water.

Michael Tricomi: I would say that's the best way.

Peggy Cornett: That's the best way.

Michael Tricomi: Definitely.

Peggy Cornett: They can get limp if they're overwatered too.

Michael Tricomi: And if they're sitting in too much water for too much time, you'll start to see signs of fungus, fungus gnats.

Peggy Cornett: My mother used to say, give it a good drink of water and then leave it alone. She'd wait a week or so before she'd water again.

Debbie Donley: I've always been guilty of overwatering. When you take a young plant out of the pot, The top would appear quite dry, but I was amazed at how much water was actually down towards the bottom of those roots. So I've had to amend my ways.

Michael Tricomi: Yeah, you want the plants to reach a little bit with their roots. If they are too wet, they don't have any reason to grow vigorously or too deep. Letting them dry out is definitely a good idea.

Peggy Cornett: That's what I do with my house plants. If they look like they might need water, I wait a week.

Lewis and Clark Plants and Vegetables

Michael Tricomi: Now we're going to talk about some plants that Lewis and Clark brought back from their exploration of the Western United States from 1803 to 1806. Jefferson, then president, commissioned their expedition.

Peggy Cornett: We do have a number of plants in the garden that are fairly drought-resistant. A lot of the plants that were brought back by Lewis and Clark were plants from the plains, such as the Narrow-leaf Echinacea, that's called the Mad Dog Plant. It's a member of the Coneflower genus, and they have really deep roots.

Michael Tricomi: The Latin name is Echinacea angustifolia. If you're wondering how it came to be called mad dog plant, it's used as a medicinal and at one time people thought could cure rabies.

Debbie Donley: One of my favorites is Gaillardia or blanket flower. It's a beautiful daisy-like flower, but it's orange and red and yellow. Very drought tolerant once it's established. It is a perennial, but it will self sow also, so there are lots of them that come up from the parent plant. They are one that benefit from deadheading. You cut the spent flowers off and then it just encourages the plant to put more flowers out.

Lewis's Prairie Flax is another absolutely beautiful plant. It's a sky blue flower. The foliage is a blue-green color, and it's very fine and feathery. It's just a really nice plant that also will self-sow. We have them sowing into the winding walk, which is rock.

Peggy Cornett: That's just a sky blue flower. I think it's such a lovely blue.

Debbie Donley: Very pretty. You can see it all the way across the garden. They bloom late spring, but then they do continue to bloom off and on throughout the season as well.

Peggy Cornett: And it was named after Meriwether Lewis. People were honored with the naming of plants. There's an annual flower that was named after William Clark called Clarkia. Elkhorn flower is another name. It's harder to grow because I think it gets too hot too fast. They're just fussy, but they're beautiful. There's pinks and white. The foliage is quite delicate. They call them Elkhorn Flowers because the shape of the petals look like tiny little elk horns or reindeer horns.

Debbie Donley: But a lot of these plants, even though they're drought resistant, you have to remember that if they're newly transplanted, they still need water until they get acclimated and start growing their roots, even in wintertime, trees and shrubs need water at least the first year.

Michael Tricomi: Jefferson once said "The greatest service which can be rendered any country is to add an useful plant to it's culture." So botanical discovery was an important goal of the Lewis and Clark Expedition.

Peggy Cornett: For the crops that were brought back by Lewis and Clark, he was really trying to introduce edible, useful crops, like the "Arikara" bean...

Michael Tricomi: Arikara bean. Mandan corn.

Peggy Cornett: The Arikara bean is doing great in the garden right now.

Michael Tricomi: It's doing really well. They had very few pods on them on a Friday, and then we came back again on Monday and it was full of pods.

Peggy Cornett: Oh, wonderful.

Michael Tricomi: I think we had rain over that weekend. They really took off.

Peggy Cornett: Lewis and Clark went to Fort Mandan. They encountered the native tribes, the Arikara, the Hidatsa, and the Mandan native people. These beans were called the Ricara or a Arikara bean. It's a little bush bean.

Michael Tricomi: It's a nice bush habit nice, green pods on them, but the bean itself is a dark yellow, you know, Arikara yellow bean, sometimes you'll hear it called.

Debbie Donley: So is it more of a dried bean for soups and things like that?

Michael Tricomi: You could eat it dried, but I have snacked on them when they're green as well. Yeah. They're a great green bean, too.

Peggy Cornett: I've never eaten them green, cause we are always growing the seed.

Debbie Donley: Fix us some for lunch, Michael.

Peggy Cornett: Let's have it, let's do it.

Michael Tricomi: Sounds good.

Peggy Cornett: Yeah, there's a beautiful squash we grew years ago.

Michael Tricomi: I think the Hidatsa squash. It's variegated.

Peggy Cornett: Oh, I hope we get that back. It's beautiful.

Michael Tricomi: We're trying to grow that for this year, so.

Peggy Cornett: The interesting thing about the corn crops, is that they were selected to grow in a very short season, so they actually mature on about a five foot plant because they didn't have a long summer. You think of corn being 12 feet tall or something.

Michael Tricomi: The Mandan red clay corn that we grow in the garden is four to five feet tall and produces ears very fast.

Peggy Cornett: The Mandan Sunflower is beautiful.

Michael Tricomi: Those tower over a lot of the other things we have in the vegetable garden. They are really impressive, massive heads.

Peggy Cornett: And they have to be sown when it's cooler weather, I think.

Michael Tricomi: They do really well sown late spring. I read somewhere that they are typically sown when the frost is beginning to melt in the Dakotas.

Debbie Donley: And they self sow.

Michael Tricomi: Speaking of self sowing, and Lewis and Clark, there was a lot of salsify that we saw coming up along the garden slope, in the orchard as well. They self sow just about everywhere.

You eat the root. It's similar to a carrot in sort of the length and the shape of the root. Oyster plant, it used to be called. Definitely has a distinct flavor to it.

Peggy Cornett: I think that's another one I've never eaten.

Debbie Donley: We need lunch, Michael.

Peggy Cornett: We need to have a...

Michael Tricomi: Yes. Arikara beans and salsify.

Peggy Cornett: Louis and Clark lunch.

Michael Tricomi: I can make a soup. It's, yeah. It's lost favor with people, I think. It's just one of those lost vegetables that you see only in certain historic gardens.

Peggy Cornett: It looks like a parsnip, doesn't it?

Michael Tricomi: It's similar, yeah. It's pretty white.

Peggy Cornett: I love parsnips.

Harvesting vegetables and flowers in July

Debbie Donley: Are they the ones that can give you the phyto?

Michael Tricomi: Yes. Unfortunately, I've experienced that before.

Peggy Cornett: The parsnips do.

Michael Tricomi: The leaves, yeah. Make sure you're wearing gloves and long sleeves when you harvest those.

Peggy Cornett: That's another issue with hot weather is you can have skin reactions to some of these plants, especially when you're sweating and your oils are on the surface of your skin. You get contact dermatitis from some of these plants.

Debbie Donley: Figs.

Peggy Cornett: Even squashes and things like that. It looks like I've been burnt on my arms. It doesn't hurt, but discolors your skin.

Michael Tricomi: We were harvesting parsnips from the garden and I had short sleeves and wearing gloves and afterwards I'd notice a rash on my forearms.

Peggy Cornett: Learn the hard way a lot of times.

Michael Tricomi: Yeah.

Peggy Cornett: Yeah. I remember that happened a few years ago.

Debbie Donley: One of our employees looked like an alien.

Peggy Cornett: Oh my.

Debbie Donley: It was bad.

Harvesting in July

Michael Tricomi: As far as harvesting from the garden, anything that's leafy or more delicate, I would definitely recommend doing that in the morning when it's cooler, otherwise it'll just wilt as soon as you pull it out of the ground.

Another big thing we are starting to do this month is a lot more seed saving. Our peas have gone to seed our spinach, brassicas, all the things like that. We're starting to harvest and save them. Ideally they're harvested on a dry day. This way the seed isn't damp to begin with, but yeah, just letting them dry out a little bit further in the greenhouse, and then breaking that down so that we can store it.

Debbie Donley: I've been doing the same thing. The Columbine is nearly all finished with producing seed, the Bachelor's Buttons. It's always a race to get to them before the goldfinches do. The Sweet William, we've also been harvesting that, and I'm actually starting to pull out sweet william plants, cause they're pretty done. But then come August when it's so beastly hot, my enthusiasm wanes. But then September, we start getting some more rain, it's cooler temperatures and the roses are putting out buds again, it just gets you revitalized and ready to keep at it.

Visitor Spotlight

Michael Tricomi: Here's some recent Monticello visitors.

Osage orange

Michael Tricomi: Our Horticulturist Robert Dowell joined Peggy to talk about an interesting tree that Lewis and Clark discovered out West and introudced to the Eastern United States

Robert Dowell: Maclura pomifera is the scientific name, and Osage orange is the common name. Osage refers to a Native American tribe in Missouri and the Arkansas region. This tree is in the mulberry family. Moraceae is the scientific name. A common feature of plants in that family is they often leak a white, milky sap. Figs will often do this, mulberries definitely do this, and if you ever prune a Maclura pomifera, you'll notice the same thing.

Peggy Cornett: It was one of the first seedlings Lewis and Clark brought back to Jefferson in 1804. It became one of the most planted trees in America, because you could hedge it down, and it has thorns and so it's like an impenetrable fence. This was before barbed wire was invented.

Robert Dowell: Right. They are quite thorny, and they can form an intense thicket.

Peggy Cornett: But also the wood has an incredible elasticity. The Native Americans really revered it because it was used for bows. So the name that the French gave it was the bois d'arc, or B O I S D apostrophe A R C, which is bow wood. But then that became corrupted into "bodark," which is B O D A R K, which is just a common name.

Robert Dowell: It's a very tough, adaptable tree.

Peggy Cornett: Very tough.

Robert Dowell: So it can take full sun, it can take very windy conditions, high heat. Its native range is in Oklahoma, Missouri, and northeastern Texas, which can be a very dry, hot, windy, sometimes desolate area.

An interesting fact that I learned today is that one of the national champions of Osage orange, which is the largest specimen of its kind in the United States, is located in Virginia, in Charlotte County, at Patrick Henry's estate. It's a tree that is, or was at one point not too long ago, 60 feet by 64 feet, which is much larger than they occur in the wild, typically.

Peggy Cornett: They used to think that the first ones brought east were by Lewis and Clark, but they've determined by that tree that the Native Americans must have brought it back much earlier.

Robert Dowell: Exactly, yes. Because when Patrick Henry bought the property, the tree was already a hundred years.

Peggy Cornett: That's incredible. The other interesting thing about the bodark or the Osage orange is that there are male and female trees. The females make this kind of a grapefruit-like fruit. You'll see it along roadsides just down the road from Monticello. And the fruits are out on the road at certain times of the year. The seed is almost like a citrus seed.

Robert Dowell: The fruit itself is like a compound structure of multiple fruits fused together, and if you were to cut one open, it would just exude that white, sticky sap. They're just very messy.

Peggy Cornett: But then the male trees get very stately. There's a huge Osage orange at the Morven estate, for example, just down the road. The bark gets very deeply grooved and it's very tall. a magnificent tree.

Robert Dowell: If you have a male and a female tree, they're able to cross pollinate. You might have a small population, but they're not a threat like autumn olive or Ailanthus or any of the more serious species.

Peggy Cornett: Definitely not a wind-borne fruit.

Robert Dowell: Yeah.


Michael Tricomi: Peggy and Robert also discussed the snowberry bush.

Peggy Cornett: Another Lewis and Clark plant that was brought back was a shrub. It came from the west coast and it bore these beautiful white berries. It was brought to Jefferson, who sent the seed on to Bernard McMahon in Philadelphia, and he was successful in growing this shrub. The Latin name is Symphoricarpos albus, Snowberry Bush.

Robert Dowell: And They're very plump. They look like a berry that's been inflated, almost.

Peggy Cornett: Jefferson sent seedlings to his friend Madame de Tessé in Paris. He was sending her lots of our native plants. He said, it's an object of singular beauty. It may never have gotten to her. I'm not sure if she was actually alive when it got to her. People in those days were shipping things back and forth, even though they may not have known someone might have died. I think that was the case with the Snowberry.

The American Chestnut

Michael Tricomi: Robert wanted to mention one last tree. It has nothing to do with Lewis and Clark but it's blooming now: the American Chestnut.

Robert Dowell: It's one of our great trees of the eastern forest. Unfortunately, a pathogen by the name of Cryphonectria parasitica, accidentally introduced in New York in the early 20th century, has spread throughout the entire native range of the American chestnut and wiped out nearly all of it, at least large, mature specimens.

Peggy Cornett: It was an Asian pathogen?

Robert Dowell: Yeah, a lot of times these plant pathogens are introduced accidentally through the transfer of plant material from one continent to another. It's a story that's played out many times, sadly.

Peggy Cornett: Yeah, that's absolutely true.

Robert Dowell: But thankfully, many trees are still alive and they're in the forest. If you're hiking in the woods in Virginia, particularly the western side, you can often see the American chestnut, but it won't be as a tree, it'll be as a shrub. What'll happen is it'll try to become a tree, and it will send up stems, and inevitably those stems will be girdled by the pathogen and die back, but the roots are still alive, and so there's this constant renewal of vegetation coming from the base of the plant. But they're still quite abundant. Occasionally, one of those stems might get tall enough that it actually blooms, and this is the time of year, when you see those blooms. If you're lucky enough, they might even be big enough to fruit, but that's still quite rare.

Peggy Cornett: It was an important tree at Monticello. The wood was very plentiful here, and a lot of the house of Monticello was built with chestnut wood, and the fences. There was so much of it that they could make paling for all the fences, including the fence that went around the vegetable and fruit garden, which was three quarters of a mile in length and 10 feet high. Used for firewood, it was everywhere. The nuts from the tree was so important for wildlife, and so it was a terrible loss for many reasons. They were ginormous trees. It must have been so heartbreaking. It's sort of like what we're going through now with the dying of a lot of the large ash trees from the emerald ash borer that I hope we can somehow stave off, cause those trees get quite large too.

Robert Dowell: There are isolated cases where resistant trees exist and even can reproduce, but they're so few and far between, and in order to wait for those resistant trees to repopulate the range of the native chestnut, we would have to wait 5,000 years. There is an organization called the American Chestnut Foundation that is trying to expedite the process, and they're back cross-breeding American chestnuts with Chinese chestnuts, which are resistant to this disease.

Peggy Cornett: And they're making big progress.

Michael Tricomi: You can check out their work at

That's it for July! Thanks for listening and check us out in August.

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