The NEW National Botanic Garden

By Kathy Jentz

A new public garden is growing on private land in Loudoun County, Virginia. The National Botanic Garden is the creation of Peter and Beata Knop, who intend to build up the garden and then leave it to the federal government with an endowment so it will last in perpetuity

Their ambitious plans include converting former cornfields into a worldclass plant collection for education and research that connects people to nature.

Naming Controversy

The news of a new public garden called the “National Botanic Garden” has some people in the local gardening world feeling a bit perturbed. “Yeah, there are a lot of people kind of got their hackles raised by that because there is a ‘national’ Botanical Garden downtown [the U.S. Botanic Garden],” said Peter.

“We’ve got a great National Arboretum, great National Portrait Gallery, great national, everything,” he continued. “There’s no great National Botanic Garden. And after our lifetimes, we’re going to leave it to the nation. That’s where that’s where we got the name national.”

The Knops are selling some of the plants they propagate at the garden as one means of supporting the property. They also host group events and art festivals.

“From an environmental point of view, we see water as being a critical resource,” said Peter, “and America’s love affair with the lawn is not something that thrills us. The only way you’re going to change people is showing them something different that they can look at and understand.”

Purpose and Mission

With more than 1,000 acres of land, much of which is the Amazing Fun Farm that welcomes school children and corporate events, the possibilities are endless. The Knops asked themselves: “How do we stimulate the imagination? How do we get people back into nature?”

With those questions in mind, they set about creating landscapes filled with large-scale sculptural art and fantasy elements.

They have built up 40 acres so far. “We’ll be about 150 acres, with a little over 100 of true gardens,” shared Peter Knop. “Then there will be about 150 acres of natural wilderness.”

Beata designed the Xeric Garden for Peter as a birthday present. “My husband was, at one time, fascinated with cacti,” she explains. “And I saw so many those cacti suffering. They didn’t have a home sitting in the greenhouse or outside. He said do something with them, so I said, okay, you are not allowed to pass that road for one month and I will create this landscape for them.” The result is the East Coast’s largest xeric garden, demonstrating water-wise gardening and low-maintenance garden techniques.

Reclaim and Reuse

Peter Knop is a fourth-generation owner of the land and previously operated a winery and a Christmas tree farm on the property. He then turned to “agricycling,” composting garden waste (leaves, fallen limbs, grass clippings, etc.) and recyclable materials such as newspapers into mulch and soil additives.

The gardens and hardscapes are predominantly made from reclaimed materials. From the brick pathways to wooden sheds, the materials are reused from other projects or repurposed from elsewhere.

Much of the stone and soil used in the garden was removed from nearby developments in Northern Virginia and brought to the location to create the undulating landscape, berms, walls, pathways, and—most notably—a mountain.

That artificial mountain has made the local news several times. Both nearby Dulles Airport and the Manassas National Battlefield Park objected to the project.

“We had a lot of problems building the mountain,” acknowledged Peter. “But now it’s the highest point between the Atlantic and the Blue Ridge you get 360-degree views.”

From the mountain’s summit, you can view four states (Virginia, West Virginia, Maryland, and Pennsylvania). The Knops anticipate it will be open to visitors next year.

Famous Friends

Frank Cabot, founder of the Garden Conservancy, was an early supporter of the project. Beata shared that “he said Peter is doing what God would have done, if he had the time and money.”

Other connections at local public gardens in the area have resulted in sharing plants and advice for developing the gardens.

“As we are just starting to open our wings, we are wide open to suggestions about how we can promote others and vice versa,” said Peter. “We have exchanged plants with numerous gardens, especially from plant collecting trips abroad, where we sometimes come up with some fun plants, like the Bulgarian fig. Another favorite we are studying to see how potentially invasive it might be is the Chinaberry (Melia azedarach), which we know has been a problem further south, but we have a Malta variety, as well as South African, which seem to do well here. We see it as a source of high-value timber as well as a beautiful decorative landscape plant, but are also looking at its potential downsides.”

“One thing we started to discuss is the need to bring in non-natives to replace those we are losing to climate change and invasive bugs. But to bring them in (and to release to the public), we have to be sure that they meet many of the qualities or characteristics of the trees/plants they are to replace from the point of view of their role in the local ecosystem, from being a food source for our existing native critters, from butterflies to mammals and all of our cold-blooded friends, reptiles, etc., and on the other side, do not have negative impacts like allelopathy for our remaining natives. It takes us 10 to 15 years to believe we have something that we do not object to seeing go ‘wild.’ Some of our Mahonia fit that category— 50 years and totally minimal spread.”

Plant Collections

The grounds feature unusual specimens as well as common ones. There are few labels at this point, and a few educational signs are sprinkled about. There are fruit tree orchards, including collections of figs and jujubes, that will be available for picking and fruitthemed festivals.

A swampy low area is host to bald cypress trees and wildlife.

Canals cut through the landscape and flow into a lake with 50 small islands—each one planted with a different species of bamboo. This is billed as “America’s largest bamboo garden” and the running varieties are kept in check by that surrounding water.

Some of these tender bamboo shoots provide food for pandas at the National Zoo.

“Bamboo is a very fast-growing plant,” said Peter. “We think that we can modify it or breed it to use for carbon sequestration.”

Art and Follies

The biggest elements of the garden currently in place are the outdoor sculptures. They are mainly formed from recycled steel and are modern in design and theme. Beata Knop is the artist behind the creations.

She is also the visionary behind the HobbitTown, an undulating dragon sculpture, and a castle (still in process). These garden follies are meant to be interacted with—visitors can scramble over the rocks and even enter the little hobbit abodes to make themselves at home there.

Future Plans

“What we’re focusing on now, or trying to, is stimulation of the imagination,” said the Knops. “To have a full and rewarding life, you need to be connected to the earth and imagination is part of it. You need to have pleasure in life. And nature delivers it in spades.”

In future years, they plan to open the property up for regular visitor hours and to start a docent program.

Visiting the National Botanic Garden

The National Botanic Garden is located at 26320 Ticonderoga Road, Chantilly, Virginia.

Currently, the gardens are only open by appointment and during specific weekends and events. To get notification of upcoming events and scheduled openings, sign up for their newsletter at https://nationalbotanicgarden.org/ Garden clubs and other horticultural-related groups can also contact the Knops to set up a visit to tour the grounds on a limited basis. o

Kathy Jentz is the founder and editor of Washington Gardener

Beech Leaf Disease Confirmed in Our Region

The Maryland Department of Agriculture has confirmed the presence of beech leaf disease (BLD) and the associated nematode, Litylenchus crenatae maccannii, in Harford County. Beech leaf disease is a new disease affecting all beech species, including American beech (Fagus grandifolia). The disease has been found in surrounding states, including Pennsylvania, Virginia, New Jersey, Ohio, Michigan, New York, Connecticut, Massachusetts, Rhode Island, New Hampshire, and Maine.

Beech Leaf Disease causes a dark banding or striping between the leaf veins. Trees with severe symptoms are heavily banded with yellowing, shrunken, and thickened leaves. The disease can kill understory trees in two years and mature trees in six to 10 years. Treatments for BLD are currently being researched.

“I applaud the department’s Forest Pest team for their quick action on identifying this disease,” said Maryland Department of Agriculture Secretary Kevin Atticks. “The team will continue to monitor and report the spread of Beech leaf disease as it occurs. Homeowners are encouraged to do the same.”

To report symptoms of BLD, data can be entered on the Tree Health Survey app (https://treehealthapp) or reported by email to fpm.mda@maryland.gov. For additional information, visit the UMD Extension Website at https://bit. ly/3Eny7eO. Additional counties are being tested for presence of the BLD and the nematode. Permanent survey plots have been set up across Maryland since 2019 o

When Should You Plant Flower Bulbs?

Do you regret not having planted flower bulbs every time spring rolls around? Well, time for a change! Don’t forget to plant them this year. Instead, treat yourself to the first spring color in the garden by planting your flower bulbs now.

Okay, this year, you’re actually going to do it. But when exactly should you plant your flower bulbs? Don’t worry: These garden jewels can be planted from September to the end of December. Just be sure to plant them before the ground freezes. Fortunately, the period for planting flower bulbs is plenty long.

Once flower bulbs are on your todo list, it’s time to select them from the huge number of varieties available at your local garden centers or from online/mail order specialty bulb catalogs. The entire assortment can be seen at www.ilsysays.com.

Now you’ve acquired your flower bulbs and you know where you want to plant them. But how exactly? Fortunately, just five easy steps are all it takes.

Step 1: Dig one hole for a group of flower bulbs or make individual holes for planting several single flower bulbs. The size of the flower bulb determines how deep it should be planted. Large flower bulbs (2 inches or larger in diameter) should be planted 6 inches deep and small flower bulbs (1–2 inches) 3 to 4 inches deep.

Step 2: Remove weeds and small stones and then work some garden mold into the soil to improve drainage.

Step 3: Place the flower bulbs gently into the soil with the point on top. Be careful not to press down too hard on the flower bulb, because this could damage it. Large flower bulbs should be planted 3 to 8 inches apart and small bulbs 1 to 3 inches apart.

Step 4: Cover the flower bulbs with the soil dug from the hole.

Step 5: If the soil is very dry, give the flower bulbs some deep watering to get established. o

Soil particles clump together—in what soil scientists call aggregates. These structures can also affect water’s ability to move in soil. Water will move down and through networks of soil pores. Some soil pore walls will retain water as well.

What are Soil Pores?

The different sizes and shapes of pores support many services in soils that ultimately benefit nature and humans

Pores are in almost everything. Look closely enough and you will find them in the wood and bricks of buildings, your skin, and the ground beneath. Soil pores are the spaces between Earth’s solid pieces (rocks, sands, silts, clays, and organic matter). The Soil Science Society of America’s (SSSA) July 1st Soils Matter blog (https://soilsmatter. wordpress.com/2023/07/01/what-aresoil-pores/) explores how different sizes and shapes of pores support many services in soils that ultimately benefit nature and humans.

Networks of differing pores support the large diversity of organisms living under ground to meet their own needs for water, air, food, and shelter.

Some pores are isolated and surrounded by solids on all sides, like a trapped bubble. Most pores are connected to each other and form pathways reaching far into the Earth. These pores are like the shops, social hangouts, roadways, and commercial flyways of the world below our feet. They are where the action happens.

According to Aaron Daigh from the University of Nebraska - Lincoln, the surfaces of pores are particularly active, with some more so than others. Pore walls built from or lined with clays and organic matter provide a fertile area for the trading, transforming, and storing of desirable chemical compounds such as plant nutrients and food for microorganisms. o

New Plant Spotlight

Aster x ‘Thunderdome’ PPAF

This hybrid with (Symphiotrichum) Aster novae-angliae and Aster oblongifolius has the purple color from the New England Aster parent and fragrant deer-resistant foliage of Aromatic Aster.

With a mounding habit and rowing 36–42" tall and 24–36" wide, plants start blooming in late August through September and into October with rich purple-colored flowers that have yellow centers. The plants have cleaner disease-resistant foliage than the New England Aster as well.

These easy to grow and hardy plants prefer an average to welldrained soil in full sun, that is also drought-tolerant. They combine nicely with other fall- bloomers and ornamental grasses like Blue Grama Grass (Bouteloua gracilis ‘Honeycomb’) and Prairie Dropseed (Sporobolus heterolepis)

For more information, contact Brent Horvath, Intrinsic Perennial Gardens, 800-648-2788, or email BrentH@intrinsicperennialgardens. com. o

Quick Links to Recent Washington Gardener Blog Posts

• Meet the New Fall Intern

• That Burning Feeling

• Balloon Flower Plant Profile

• Tomato Taste Results

See more Washington Gardener blog posts at WashingtonGardener.blogspot.com o

September–October Garden To-Do List

• Keep an eye out for the first frost date. In Zone 6, it is expected between September 30 and October 30. In Zone 7, it is predicted for between October 15 and November 15.

• Divide and transplant perennials—in particular, peonies and iris.

• Pick apples at a local pick-your-own farm or visit a local farmer’s market.

• Pot up rosemary and chives for over-wintering indoors.

• Take cuttings from coleus and begonias to propagate and overwinter indoors.

• Look out for poison ivy vines, which will turn crimson in the fall and be easy to distinguish from other vines.

• Check your local garden center for end-of-summer bargains.

• Put netting over your pond to prevent the accumulation of leaves and debris.

• Start feeding birds to get them in the habit for this winter.

• Attend a local garden club meeting or plant exchange.

• Pick mature tomatoes and peppers to ripen on your window sills.

• Turn your compost pile weekly and don’t let it dry out. Work compost into your planting beds.

• Remove undeveloped or shriveled fruit from fruit trees and compost them.

• Plant evergreens for winter interest.

• Plant garlic bulbs.

• Collect plant seeds for next year’s planting and for trading at the annual Washington Gardener Magazine Seed Exchanges.

• Plant hardy mums and fall season annuals.

• Fertilize your lawn and re-seed if needed.

• Dig up your Gladiolus, Canna, Caladiums, and other tender bulbs; cut off foliage; let dry for a week; and store for the winter.

• Transplant trees and shrubs.

• Harvest your herbs often and keep them trimmed back to encourage leafy growth.

• Bring in houseplants if you took them outdoors for the summer.

• If your conifers start shedding their needles or your spring bulb foliage starts peeking out of the ground, don’t worry. This is normal for our autumn cycle.

• Leave hummingbird feeders out until October 15.

• Start bulb plantings of early-spring bloomers at the end of the month.

• Watch your pumpkins/squash. Harvest them when their rinds are dull and hard.

• Divide ornamental grasses.

• Cut herbs and flowers for drying indoors.

• Plant strawberries in a site with good drainage for harvesting next spring.

• Look out for slug eggs grouped under sticks and stones—they are the size of BBs and pale in color.

• Plant cover crops in vegetable gardens and annual beds (for example, rye, clover, hairy vetch, and winter peas).

• Begin conditioning the Poinsettias and Christmas cacti to get them ready for the upcoming holiday season.

• Bring Amaryllis indoors before a hard freeze. Repot every other year at this time. Store in a cool, dark place and do not water until flower buds or leaves emerge.

• Your summer annuals will be reviving now with cooler temps and some rain. Cut back any ragged growth and give them some fertilizer. They should put on a good show until the first hard frost. o